LTE TDD eRAN11.1
Optional Feature Description
Issue
02
Date
2016-07-30
HUAWEI TECHNOLOGIES CO., LTD.
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Contents 1 Change History .............................................................................................................................. 1 2 Voice & Other Services ................................................................................................................ 3 2.1 VoLTE ........................................................................................................................................................................... 3 2.1.1 TDLOFD-001016 VoIP Semi-persistent Scheduling ................................................................................................. 3 2.1.2 TDLOFD-001017 RObust Header Compression (ROHC) ........................................................................................ 4 2.1.3 TDLOFD-001048 TTI Bundling ............................................................................................................................... 6 2.1.4 TDLOFD-081229 Voice Characteristic Awareness Scheduling ................................................................................. 6 2.1.5 TDLOFD-111202 Coverage-based VoLTE Experience Optimization ....................................................................... 8 2.1.6 TDLOFD-111207 VoLTE Rate Control ..................................................................................................................... 9 2.1.7 TDLOFD-001022 SRVCC to UTRAN .................................................................................................................... 11 2.1.8 TDLOFD-001023 SRVCC to GERAN .................................................................................................................... 12 2.2 CSFB .......................................................................................................................................................................... 14 2.2.1 TDLOFD-001033 CS Fallback to UTRAN ............................................................................................................. 14 2.2.2 TDLOFD-001052 Flash CS Fallback to UTRAN ................................................................................................... 15 2.2.3 TDLOFD-001068 CS Fallback with LAI to UTRAN ............................................................................................. 17 2.2.4 TDLOFD-001088 CS Fallback Steering to UTRAN ............................................................................................... 18 2.2.5 TDLOFD-081223 Ultra-Flash CSFB to UTRAN .................................................................................................... 19 2.2.6 TDLOFD-001034 CS Fallback to GERAN ............................................................................................................. 21 2.2.7 TDLOFD-001053 Flash CS Fallback to GERAN ................................................................................................... 22 2.2.8 TDLOFD-001069 CS Fallback with LAI to GERAN ............................................................................................. 23 2.2.9 TDLOFD-001089 CS Fallback Steering to GERAN ............................................................................................... 24 2.2.10 TDLOFD-081203 Ultra-Flash CSFB to GERAN .................................................................................................. 25 2.2.11 TDLOFD-001035 CS Fallback to CDMA2000 1xRTT ......................................................................................... 27 2.2.12 TDLOFD-001090 Enhanced CS Fallback to CDMA2000 1xRTT ........................................................................ 29 2.2.13 TDLOFD-001091 CS Fallback to CDMA2000 1xRTT Based on Frequency-specific Factors ............................. 30 2.3 Increment Value Service ............................................................................................................................................. 32 2.3.1 TDLOFD-001047 LoCation Services(LCS) ............................................................................................................ 32 2.3.2 TDLOFD-001092 CMAS Support........................................................................................................................... 33 2.3.3 TDLOFD-081222 Dynamic Service-specific Access Control ................................................................................. 34 2.3.4 TDLOFD-070220 eMBMS Phase 1 based on Centralized MCE Architecture ........................................................ 36 2.3.4.1 TDLOFD-07022001 Multi-cell transmission in MBSFN area ............................................................................. 38 2.3.4.2 TDLOFD-07022002 Mixed transmission of unicast and broadcast...................................................................... 39
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2.3.4.3 TDLOFD-07022003 Data synchronization ........................................................................................................... 40 2.3.4.4 TDLOFD-07022004 Session admission control ................................................................................................... 41 2.3.5 TDLOFD-080210 eMBMS Service Continuity ....................................................................................................... 42 2.4 Video Service Optimization ........................................................................................................................................ 43 2.4.1 TDLOFD-111205 Busy-Hour Download Rate Control ........................................................................................... 43 2.4.2 TDLOFD-111206 Video Service Rate Adaption...................................................................................................... 44 2.4.3 TDLOFD-110225 Uplink Data Compression .......................................................................................................... 45
3 Radio & Performance ................................................................................................................. 47 3.1 2-layer Mutil-Antenna ................................................................................................................................................ 47 3.1.1 TDLOFD-001001 DL 2x2 MIMO ........................................................................................................................... 47 3.1.2 TDLOFD-001030 Support of UE Category 2/3/4 ................................................................................................... 48 3.1.3 TDLOFD-001049 Single Streaming Beamforming ................................................................................................. 49 3.1.4 TDLOFD-001061 Dual Streaming Beamforming ................................................................................................... 50 3.1.5 TDLOFD-001077 MU-Beamforming...................................................................................................................... 51 3.1.6 TDLOFD-001005 UL 4-Antenna Receive Diversity ............................................................................................... 53 3.1.7 TDLOFD-001058 UL 2x4 MU-MIMO ................................................................................................................... 54 3.1.8 TDLOFD-001062 UL 8-Antenna Receive Diversity ............................................................................................... 55 3.1.9 TDLOFD-081205 UL 2x8 MU-MIMO ................................................................................................................... 56 3.2 Interference Handling ................................................................................................................................................. 57 3.2.1 TDLOFD-001012 UL Interference Rejection Combining ....................................................................................... 57 3.2.2 TDLOFD-060201 Adaptive Inter-Cell Interference Coordination ........................................................................... 58 3.2.3 TDLOFD-001094 Control Channel IRC ................................................................................................................. 59 3.2.4 TDLOFD-001075 SFN ............................................................................................................................................ 60 3.2.5 TDLOFD-002008 Adaptive SFN/SDMA ................................................................................................................ 62 3.2.6 TDLOFD-001098 Inter-BBP SFN ........................................................................................................................... 63 3.2.7 TDLOFD-001080 Inter-BBU SFN .......................................................................................................................... 64 3.2.8 TDLOFD-001081 Inter-BBP Adaptive SFN/SDMA ............................................................................................... 65 3.2.9 TDLOFD-001082 Inter-BBU Adaptive SFN/SDMA .............................................................................................. 66 3.2.10 TDLOFD-070227 PDCCH DCS in SFN ............................................................................................................... 67 3.2.11 TDLOFD-081221 PDCCH SDMA in SFN ............................................................................................................ 68 3.2.12 TDLOFD-070223 Multi-Cell Interference Randomizing and Coordination ......................................................... 69 3.2.13 TDLOFD-080203 Coordinated Scheduling based Power Control ......................................................................... 70 3.2.14 TDLOFD-081217 Interference Detection and Suppression ................................................................................... 71 3.2.15 TDLOFD-081219 Interference Based Uplink Power Control ............................................................................... 72 3.2.16 TDLOFD-081232 Enhanced Uplink Power Control ............................................................................................. 73 3.2.17 TDLOFD-110205
Intra-eNodeB Uplink Coordinated Scheduling ..................................................................... 74
3.2.18 TDLOFD-110206 Inter-eNodeB Uplink Coordinated Scheduling ........................................................................ 75 3.2.19 TDLOFD-111208 Uplink Interference Coordination............................................................................................. 76 3.2.20 TDLOFD-111201 Remote Interference Adaptive Avoidance ................................................................................ 77 3.2.21 TDLOFD-001066 Intra-eNodeB UL CoMP .......................................................................................................... 79 3.2.22 TDLOFD-081207 UL CoMP based on Coordinated BBU .................................................................................... 81
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3.3 QoS ............................................................................................................................................................................. 84 3.3.1 TDLOFD-001026 Optional uplink-downlink subframe configuration .................................................................... 84 3.3.1.1 TDLOFD-00102601 uplink-downlink subframe configuration type 0 ................................................................. 84 3.3.1.2 TDLOFD-00102602 uplink-downlink special subframe configuration type 4 ..................................................... 85 3.3.1.3 TDLOFD-00102603 uplink-downlink special subframe configuration type 5 ..................................................... 86 3.3.1.4 TDLOFD-00102604 uplink-downlink special subframe configuration type 6 ..................................................... 87 3.3.1.5 TDLOFD-00102605 uplink-downlink special subframe configuration type 9 ..................................................... 88 3.3.2 TDLOFD-001006 UL 64QAM ................................................................................................................................ 89 3.3.3 TDLOFD-110227 Traffic Model Based Performance Optimization ....................................................................... 90 3.3.4 TDLOFD-001015 Enhanced Scheduling ................................................................................................................. 91 3.3.4.1 TDLOFD-00101501 CQI Adjustment .................................................................................................................. 91 3.3.4.2 TDLOFD-00101502 Dynamic Scheduling ........................................................................................................... 92 3.3.5 TDLOFD-081231 Optimized CFI-Calculation-based MCS Index Selection .......................................................... 93 3.3.6 TDLOFD-081233 Optimized Uplink Resource Allocation ..................................................................................... 94 3.3.7 TDLOFD-070222 Scheduling Based on Max Bit Rate ........................................................................................... 95 3.3.8 TDLOFD-001028 TCP Proxy Enhancer (TPE) ....................................................................................................... 95 3.3.9 TDLOFD-001027 Active Queue Management (AQM) ........................................................................................... 96 3.3.10 TDLOFD-001029 Enhanced Admission Control ................................................................................................... 97 3.3.10.1 TDLOFD-00102901 Radio/transport Resource Pre-emption ............................................................................. 97 3.3.11 TDLOFD-001054 Flexible User Steering .............................................................................................................. 98 3.3.11.1 TDLOFD-00105401 Camp & Handover Based on SPID ................................................................................... 98 3.3.11.2 TDLOFD-00105402 WBB Subscriber Identification and Specified QoS Guarantee ....................................... 100 3.3.12 TDLOFD-001059 UL Pre-allocation Based on SPID .......................................................................................... 102 3.3.13 TDLOFD-001109 DL Non-GBR Packet Bundling .............................................................................................. 102 3.4 Smart Phone Optimization ........................................................................................................................................ 103 3.4.1 TDLOFD-001105 Dynamic DRX.......................................................................................................................... 103 3.4.1.1 TDLOFD-00110501 Dynamic DRX ................................................................................................................... 103 3.4.1.2 TDLOFD-00110502 High-Mobility-Triggered Idle Mode ................................................................................. 104 3.4.2 TDLOFD-080202 Intelligent Access Class Control .............................................................................................. 105 3.5 Inter-RAT Mobility Solution ..................................................................................................................................... 106 3.5.1 TDLOFD-001019 PS Inter-RAT Mobility between E-UTRAN and UTRAN ....................................................... 106 3.5.2 TDLOFD-001043 Service based Inter-RAT handover to UTRAN ........................................................................ 109 3.5.3 TDLOFD-001072 Distance based Inter-RAT handover to UTRAN ...................................................................... 110 3.5.4 TDLOFD-001078 E-UTRAN to UTRAN CS/PS Steering .................................................................................... 110 3.5.5 TDLOFD-001020 PS Inter-RAT Mobility between E-UTRAN and GERAN ....................................................... 111 3.5.6 TDLOFD-001046 Service based Inter-RAT handover to GERAN ........................................................................ 114 3.5.7 TDLOFD-001073 Distance based Inter-RAT handover to GERAN ...................................................................... 115 3.5.8 TDLOFD-001021 PS Inter-RAT Mobility between E-UTRAN and CDMA2000 ................................................. 115 3.5.9 TDLOFD-001111 PS Mobility from E-UTRAN to CDMA2000 HRPD Based on Frequency-specific Factors ... 117 3.5.10 TDLOFD-001050 Mobility between LTE TDD and LTE FDD ........................................................................... 118 3.6 High Speed Mobility................................................................................................................................................. 119 3.6.1 TDLOFD-001007 High Speed Mobility ................................................................................................................ 119
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3.6.2 TDLOFD-080205 Handover Enhancement at Speed Mobility .............................................................................. 121 3.7 Coverage Enhancement ............................................................................................................................................ 123 3.7.1 TDLOFD-001009 Extended Cell Access Radius ................................................................................................... 123 3.7.2 TDLOFD-001031 Extended CP ............................................................................................................................ 124 3.8 WBB ......................................................................................................................................................................... 125 3.8.1 TDLOFD-110223 Specified Service Carrier ......................................................................................................... 125
4 Networking & Transmission & Security .............................................................................. 127 4.1 Transmission & Synchronization .............................................................................................................................. 127 4.1.1 TDLOFD-001076 CPRI Compression................................................................................................................... 127 4.1.2 TDLOFD-081214 Enhanced CPRI Compression .................................................................................................. 128 4.1.3 TDLOFD-003002 2G/3G and LTE Co-transmission ............................................................................................. 129 4.1.4 TDLOFD-003011 Enhanced Transmission QoS Management .............................................................................. 130 4.1.4.1 TDLOFD-00301101 Transport Overbooking ..................................................................................................... 130 4.1.4.2 TDLOFD-00301102 Transport Differentiated Flow Control .............................................................................. 131 4.1.4.3 TDLOFD-00301103 Transport Resource Overload Control ............................................................................... 132 4.1.5 TDLOFD-003012 IP Performance Monitoring ...................................................................................................... 133 4.1.5.1 TDLOFD-00301201 IP Performance Monitoring ............................................................................................... 133 4.1.5.2 TDLOFD-00301202 Transport Dynamic Flow Control ..................................................................................... 133 4.1.6 TDLOFD-003018 IP Active Performance Measurement ....................................................................................... 134 4.1.7 TDLOFD-003013 Enhanced Synchronization ....................................................................................................... 136 4.1.7.1 TDLOFD-00301302 IEEE1588 V2 Clock Synchronization ............................................................................... 136 4.1.8 TDLOFD-081213 Inter-BBU Clock Sharing ......................................................................................................... 139 4.1.9 TDLOFD-003016 Different Transport Paths based on QoS Grade ....................................................................... 140 4.1.10 TDLOFD-001134 Virtual Routing and Forwarding ............................................................................................. 141 4.1.11 TDLOFD-003017 S1 and X2 over IPv6 .............................................................................................................. 142 4.1.12 TDLOFD-003024 IPsec for IPv6 ......................................................................................................................... 143 4.2 Security ..................................................................................................................................................................... 145 4.2.1 TDLOFD-001010 Security Mechanism ................................................................................................................. 145 4.2.1.1 TDLOFD-00101001 Encryption: AES ............................................................................................................... 145 4.2.1.2 TDLOFD-00101002 Encryption: SNOW 3G ..................................................................................................... 145 4.2.1.3 TDLOFD-00101003 Encryption: ZUC ............................................................................................................... 146 4.2.2 TDLOFD-003009 IPsec ......................................................................................................................................... 147 4.2.3 TDLOFD-081211 eNodeB Supporting IPsec Redirection ..................................................................................... 148 4.2.4 TDLOFD-003010 Public Key Infrastructure (PKI) ............................................................................................... 150 4.2.5 TDLOFD-081206 eNodeB Supporting Multi-operator PKI .................................................................................. 152 4.2.6 TDLOFD-003014 Integrated Firewall ................................................................................................................... 154 4.2.6.1 TDLOFD-00301401 Access Control List (ACL) ............................................................................................... 154 4.2.6.2 TDLOFD-00301402 Access Control List (ACL) autogeneration ....................................................................... 154 4.2.7 TDLOFD-003015 Access Control based on 802.1x .............................................................................................. 155 4.2.8 TDLOFD-070211 IPsec Redundancy among Multi-SeGWs ................................................................................. 156 4.2.9 TDLOFD-070212 eNodeB Supporting PKI Redundancy ..................................................................................... 158
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4.3 Reliability ................................................................................................................................................................. 159 4.3.1 TDLOFD-001018 S1-flex ...................................................................................................................................... 159 4.3.2 TDLOFD-003004 Ethernet OAM .......................................................................................................................... 161 4.3.2.1 TDLOFD-00300401 Ethernet OAM (IEEE 802.3ah) ......................................................................................... 161 4.3.2.2 TDLOFD-00300403 Ethernet OAM (Y.1731) .................................................................................................... 162 4.3.3 TDLOFD-003005 OM Channel Backup ................................................................................................................ 163 4.3.4 TDLOFD-003006 IP Route Backup ...................................................................................................................... 163 4.3.5 TDLOFD-003007 Bidirectional Forwarding Detection ......................................................................................... 164 4.3.6 TDLOFD-003008 Ethernet Link Aggregation (IEEE 802.3ad) ............................................................................. 165 4.4 RAN Sharing ............................................................................................................................................................ 167 4.4.1 TDLOFD-001036 RAN Sharing with Common Carrier ........................................................................................ 167 4.4.2 TDLOFD-001037 RAN Sharing with Dedicated Carrier ...................................................................................... 168 4.4.3 TDLOFD-081224 Hybrid RAN Sharing ............................................................................................................... 170 4.4.4 TDLOFD-001086 RAN Sharing by More Operators ............................................................................................ 172 4.4.5 TDLOFD-001112 MOCN Flexible Priority Based Camping ................................................................................ 173 4.4.6 TDLOFD-001133 Multi Operators SPID Policy ................................................................................................... 174 4.5 Advance Micro.......................................................................................................................................................... 175 4.5.1 TDLOFD-001057 Load Balancing based on Transport QoS ................................................................................. 175 4.5.2 TDLOFD-003022 PPPoE ...................................................................................................................................... 176
5 O&M ............................................................................................................................................ 177 5.1 SON .......................................................................................................................................................................... 177 5.1.1 TDLOFD-002001 Automatic Neighbour Relation (ANR) .................................................................................... 177 5.1.2 TDLOFD-002002 Inter-RAT ANR ........................................................................................................................ 179 5.1.3 TDLOFD-002004 Self-configuration .................................................................................................................... 182 5.1.4 TDLOFD-002007 PCI Collision Detection & Self-Optimization ......................................................................... 184 5.1.5 TDLOFD-110231 Auto Neighbor Group Configuration ....................................................................................... 186 5.1.6 TDLOFD-002005 Mobility Robust Optimization (MRO)..................................................................................... 187 5.1.7 TDLOFD-081201 Specified PCI Group-based Neighboring Cell Management ................................................... 189 5.1.8 TDLOFD-081209 Automatic Congestion Handling .............................................................................................. 190 5.1.9 TDLOFD-002011 Antenna Fault Detection ........................................................................................................... 192 5.1.10 TDLOFD-002012 Cell Outage Detection and Compensation ............................................................................. 193 5.2 MLB ......................................................................................................................................................................... 194 5.2.1 TDLOFD-001032 Intra-LTE Load Balancing ....................................................................................................... 194 5.2.2 TDLOFD-001123 Enhanced Intra-LTE Load Balancing ....................................................................................... 196 5.2.3 TDLOFD-070215 Intra-LTE User Number Load Balancing ................................................................................. 197 5.2.4 TDLOFD-081210 Multi-RRU Cell Load Balancing ............................................................................................. 198 5.2.5 TDLOFD-001044 Inter-RAT Load Sharing to UTRAN ........................................................................................ 199 5.2.6 TDLOFD-001045 Inter-RAT Load Sharing to GERAN ........................................................................................ 201 5.3 Power Saving ............................................................................................................................................................ 202 5.3.1 TDLOFD-001039 RF Channel Intelligent Shutdown ............................................................................................ 202 5.3.2 TDLOFD-001040 Low Power Consumption Mode .............................................................................................. 203
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5.3.3 TDLOFD-001041 Power Consumption Monitoring .............................................................................................. 204 5.3.4 TDLOFD-001042 Intelligent Power-Off of Carriers in the Same Coverage ......................................................... 204 5.3.5 TDLOFD-001056 PSU Intelligent Sleep Mode ..................................................................................................... 205 5.3.6 TDLOFD-001070 Symbol Power Saving .............................................................................................................. 206 5.3.7 TDLOFD-001071 Intelligent Battery Management ............................................................................................... 208 5.4 Antenna Management ............................................................................................................................................... 209 5.4.1 TDLOFD-001024 Remote Electrical Tilt Control ................................................................................................. 209
6 Acronyms and Abbreviations ................................................................................................. 211
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LTE TDD Optional Feature Description
1 Change History
1
Change History
Issue
Date
Author
Change Description
02
2016-07 -30
Xu Xiaohong
This is Issue 02 for GA version.
01
2016-01 -01
Xu Nan
This is Issue 01.
Draft A
2015-11 -18
Xu Nan
This document is based on LTE TDD eRAN11.0 Optional Feature Description. The following features have been added or enhanced: New features:
TDLOFD-111207 VoLTE Rate Control
TDLOFD-111202 Coverage-based VoLTE Experience Optimization
TDLOFD-111205 Busy-Hour Download Rate Control
TDLOFD-111206 Video Service Rate Adaption
TDLOFD-110225 Uplink Data Compression
TDLOFD-111208 Uplink Interference Coordination
TDLOFD-111201 Remote Interference Adaptive Avoidance
Enhanced features:
Issue 02 (2016-07-30)
TDLOFD-081222 Dynamic Service-specific Access Control
TDLOFD-081222 Dynamic Service-specific Access Control
TDLOFD-080202 Intelligent Access Class Control
TDLOFD-081213 Inter-BBU Clock Sharing
TDLOFD-070211 IPsec Redundancy among Multi-SeGWs
TDLOFD-003007 Bidirectional Forwarding
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LTE TDD Optional Feature Description
Issue
1 Change History
Date
Author
Change Description Detection
Issue 02 (2016-07-30)
TDLOFD-002001 Automatic Neighbour Relation (ANR)
TDLOFD-002002 Inter-RAT ANR
TDLOFD-002004 Self-configuration
TDLOFD-110231 Auto Neighbor Group Configuration
TDLOFD-081209 Automatic Congestion Handling
TDLOFD-001032 Intra-LTE Load Balancing
TDLOFD-070215 Intra-LTE User Number Load Balancing
TDLOFD-001024 Remote Electrical Tilt Control
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LTE TDD Optional Feature Description
2 Voice & Other Services
2
Voice & Other Services
2.1 VoLTE 2.1.1 TDLOFD-001016 VoIP Semi-persistent Scheduling Availability This feature was introduced in LTE TDD eRAN2.0. This feature is applicable to micro eNodeBs from LTE TDD eRAN6.1.
Summary Semi-persistent scheduling is a technique for efficiently assigning resources for spurts of traffic in a wireless communications system. A semi-persistent resource assignment is valid as long as more data is sent within a predetermined time period after the last data sent, and expires if no data is sent within the predetermined time period. For voice over IP (VoIP) services, a semi-persistent resource assignment may be granted for a voice frame in anticipation of a voice service traffic spurt.
Benefits This feature is essential to VoIP services and provides the following benefits:
Guarantees the QoS for VoIP services.
Reduces the control signaling overhead for VoIP transmission.
Maximizes resource utilization by dynamically activating or deactivating resource allocation according to the transition between silent period and talk spurt.
Description This feature is essential to delivery of the voice service with acceptable quality. E-UTRAN is optimized in terms of packet data transfer, and the core network is purely IP packet-based. The voice service data is transmitted by means of VoIP instead of using the traditional circuit-based method. To ensure voice quality, a semi-persistent scheduling solution is used for VoIP services. VoIP is a real-time service with small and fixed-length data packets and constant arrival time. VoIP traffic consists of talk spurts and silent periods. The adaptive multirate (AMR) codec can
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2 Voice & Other Services
yield quiet burst voice traffic. During a talk spurt, VoIP packets normally arrive at intervals of 20 ms. During a silent period, silence indicator (SID) packets arrive at intervals of 160 ms. During semi-persistent scheduling, the eNodeB allocates a certain amount of resources (such as resource blocks) for the voice call during the call setup period by using radio resource control (RRC) signaling. The allocation is semi-persistent and does not require a repeat request by using UL/DL control signaling until the call is complete and the resources are released. To maximize resource utilization during a silent period, resource allocation is deactivated by means of explicit signaling exchanged over the physical downlink control channel (PDCCH). When the VoIP call transits from silent period to talk spurt, similar PDCCH signaling is used to activate the semi-persistent resource allocation. The semi-persistent scheduling significantly reduces the PDCCH overhead and ensures the QoS for VoIP services by reserving resources in a semi-persistent manner. It also improves resource utilization by dynamically activating or deactivating resource allocation between talk spurt and silent period.
Enhancement None
Dependency UEs must support semi-persistent scheduling. This feature cannot be used with the following features:
TDLOFD-001048 TTI Bundling
TDLOFD-001007 High Speed Mobility
2.1.2 TDLOFD-001017 RObust Header Compression (ROHC) Availability This feature was introduced in LTE TDD eRAN2.0.
Summary ROHC provides an efficient and flexible header compression mechanism, which is particularly important for improving the bandwidth utilization for VoIP services with a small payload.
Benefits This feature provides the following benefits:
Reduces the IP packet header size
Significantly increases the ratio of the payload to header for VoIP services with a small payload
Shortens the response time to guarantee the high usage of links between eNodeBs and UEs
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Description As more and more wireless technologies are being deployed to carry IP traffic, the total header size needs to be reduced during transmission because of large packet overhead. This improves bandwidth resource utilization, particularly for services with a small payload (for example, VoIP services). On an end-to-end transmission path, the entire header information is necessary for all packets in the flow. However, over a radio link (a portion of the end-to-end path), some data in the information is redundant and can be reduced because they can be transparently recovered at the receiving end. The ROHC protocol provides an efficient, flexible, and future-proof header compression method to compress and decompress IP, UDP, RTP, and ESP packet headers. It is designed to operate efficiently and robustly over various link technologies with different characteristics, especially for wireless transmission. In an LTE system, ROHC is implemented in Packet Data Convergence Protocol (PDCP) entities associated with user-plane packets. In the UL, the packets are compressed by the UE and decompressed by the eNodeB. In the DL, the packets are compressed by the eNodeB and decompressed by the UE. The relative gain for specific flows or applications depends on the size of the payload used in each packet. Header compression significantly improves the bandwidth utilization for VoIP services with a small payload. Huawei LTE eNodeBs support profiles 0x0000 to 0x0004 based on both IPv4 and IPv6. Table 2-1 shows the profile identifiers and their associated header compression protocols. Table 2-1 ROHC profile identifier and header compression protocol Profile Identifier
Header Compression Protocol
0x0000
No compression
0x0001
RTP, UDP, IP
0x0002
UDP, IP
0x0003
ESP, IP
0x0004
IP
Enhancement None
Dependency UEs must support ROHC.
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2.1.3 TDLOFD-001048 TTI Bundling Availability This feature was introduced in LTE TDD eRAN3.0.
Summary When this feature is enabled, cell edge users (CEUs) with a low signal to interference plus noise ratio (SINR) in the uplink can retransmit the same data block in continuous subframe.
Benefits TTI bundling improves uplink coverage and indoor reception for VoIP services.
Description The activation and deactivation of TTI bundling transmission is controlled by RRC signaling messages. If TTI bundling is configured at the RRC layer, TTI_BUNDLE_SIZE specifies the number of TTIs in a TTI bundle. Within a TTI bundle, hybrid automatic repeat request (HARQ) retransmissions are non-adaptive and are performed without waiting for feedback (for example, NACK or ACK) related to previous transmissions according to TTI_BUNDLE_SIZE. A feedback for a TTI bundle is only received for a specific TTI corresponding to TTI_BUNDLE_SIZE. A retransmission of a TTI bundle is also a TTI bundle. TTI_BUNDLE_SIZE is fixed at 4. ACK is short for acknowledgement and NACK is short for negative acknowledgement. According to 3GPP specifications, only uplink-downlink subframe configuration types 0, 1, and 6 support this feature.
Enhancement None
Dependency UEs must support TTI bundling. This feature cannot be used with the following features:
TDLBFD-00100701 uplink-downlink subframe configuration type1&2 (type 2 is not supported)
TDLOFD-001016 VoIP Semi-persistent Scheduling
TDLOFD-001058 UL 2x4 MU-MIMO
2.1.4 TDLOFD-081229 Voice Characteristic Awareness Scheduling Availability This feature is
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Applicable to Micro from LTE TDD eRAN8.1.
Applicable to LampSite from LTE TDD eRAN8.1.
Summary This feature is implemented based on uplink delay-based dynamic scheduling and uplink VoLTE volume estimation for dynamic scheduling. This feature adjusts scheduling priorities and estimates uplink volume to be scheduled to improve uplink voice performance in heavy traffic scenarios. In heavy-traffic scenarios where data and voice services coexist, the eNodeB prioritizes SR scheduling requests. This allows voice services to be preferentially scheduled, which ensures the voice quality. The independent configuration for voice inactivity timer improves user experiences on voice services.
Benefits This feature improves uplink voice performance in heavy traffic scenarios.
Description
Uplink delay-based dynamic scheduling
The eNodeB prioritizes voice packets based on their waiting times; a longer waiting time indicates a higher priority. This way, the eNodeB makes a balance among scheduling queues and improves voice quality, especially the voice quality of UEs at the cell edge where channel conditions are poor.
Uplink VoLTE volume estimation for dynamic scheduling The eNodeB estimates uplink VoLTE volume for dynamic scheduling based on the VoLTE model and uplink scheduling intervals: −
During talk spurts, the eNodeB estimates the number of voice packets in the UE buffer based on their uplink scheduling intervals and then calculates the volume of voice packets based on the size of a voice packet.
−
During silent periods, the eNodeB takes the size of a voice packet as the uplink VoLTE volume for dynamic scheduling.
When a called UE does not answer the call, the calling UE is released after the UE inactivity timer expires. In this case, the calling UE in idle mode may be reselected to a cell that does not support voice services. If the called UE starts to answer the call, the service with QCI of 1 of the calling UE fails to be set up. With independent configuration for voice inactivity timer, the UEs can distinguish voice and non-voice scenarios. That is, the length of the UE inactivity timer can be independently configured to avoid the preceding negative impact.
Enhancement
eRAN TDD 11.0 UL Delay-based Dynamic Scheduling is enhanced in eRAN11.0. In heavy-traffic scenarios where data and voice services coexist, the eNodeB prioritizes SR scheduling requests. This allows voice services to be preferentially scheduled, which ensures the voice quality.
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Dependency
eNodeB None
eCo None
UE None
Transport network None
CN None
OSS None
Other features This feature applies only to VoLTE services. This feature requires the following features:
−
TDLBFD-002025 Basic Scheduling
−
TDLOFD-00101502 Dynamic Scheduling
Others None
2.1.5 TDLOFD-111202 Coverage-based VoLTE Experience Optimization Availability This feature is:
Available in macro eNodeBs as of LTE TDD eRAN11.1.
Available in LampSite eNodeBs as of LTE TDD eRAN11.1.
Available in micro eNodeBs as of LTE TDD eRAN11.1.
Summary The coverage-based VoLTE experience optimization feature performs admission decision on dedicated voice bearers based on the uplink channel quality. The eNodeB identifies UEs in areas with weak coverage and rejects setup of their dedicated voice bearers. The IMS instructs the UEs to retry CSFB-based calls so that voice calls can be made successfully.
Benefits This feature improves user experience for VoLTE UEs in areas with weak coverage and prevents Before Alerting SRVCC (bSRVCC) call drops.
Description After this feature is enabled, the eNodeB calculates the uplink path loss (PathLoss) based on the power headroom report (PHR) received from a NE, and measures the uplink SRS Issue 02 (2016-07-30)
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reference signals to obtain the uplink SINR. Then, the eNodeB determines whether the UE is located in an area with weak coverage based on the PathLoss and SINR. The eNodeB rejects setup of the dedicated voice bearers for UEs in areas with weak coverage.
When the call is a mobile originated call, the IMS sends a SIP message (SIP 500/380/503) for the UE to trigger the CSFB procedure if setup of the dedicated voice bearer fails.
When the call is a mobile terminated call (MTC), the IMS initiates the MTC procedure in the GSM CS domain so that the UE triggers the CSFB procedure.
The IMS enables UEs in areas with weak coverage to trigger the CSFB procedure so that voice calls can be made successfully.
Enhancement None
Dependency
eNodeB None
eCoordinator None
UE The UE must be capable of initiating a CSFB-based call upon receipt of error codes such as SIP 500/380/503.
CN The IMS must be capable of instructing a UE to initiate the CSFB procedure in case of a failed voice service setup.
Other NEs None
Other features This feature requires any of the following features: TDLOFD-001034 CS Fallback to GERAN TDLOFD-001053 Flash CS Fallback to GERAN TDLOFD-081203 Ultra-Flash CSFB to GERAN
Others None
2.1.6 TDLOFD-111207 VoLTE Rate Control Availability This feature is:
Available in macro eNodeBs as of LTE TDD eRAN11.1.
Available in LampSite eNodeBs as of LTE TDD eRAN11.1.
Available in micro eNodeBs as of LTE TDD eRAN11.1.
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Summary VoLTE Rate Control adjusts the AMR-NB/AMR-WB rate for uplink voice services depending on the uplink channel quality and voice quality. The feature helps improve the voice quality and LTE uplink coverage.
Benefits This feature helps improve the voice quality and LTE uplink coverage.
Description Figure 2-1 Before the feature is enabled
Before the feature is enabled, UEs use a fixed coding rate. As shown in Figure 2-1, a UE uses a high voice coding rate during the access. When the UE moves to a weak coverage area, the coding rate remains unchanged. As a result, the uplink voice coverage is restricted. Figure 2-2 After the feature is enabled
After this feature is enabled, the eNodeB adjusts the AMR-NB/AMR-WB rate for uplink voice services depending on the uplink channel quality and voice quality, as shown in Figure 2-2.
When the uplink channel quality and voice quality are favorable, a high voice coding rate is used to further improve the voice quality.
When the uplink channel quality and voice quality are poor, a low voice coding rate is used to improve the uplink voice coverage.
Enchancement None
Dependency
eNodeB None
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eCoordinator None
UE The UE supports AMR rate adjustment.
Core network The CN works with the SBC to support the SBC joint rate adjustment solution.
Other NEs None
Other features None
Others None
2.1.7 TDLOFD-001022 SRVCC to UTRAN Availability This feature was introduced in LTE TDD eRAN2.1.
Summary SRVCC is a solution to provide voice services on LTE networks. During initial LTE network deployment, when UEs running voice services move out of an LTE network, voice services can continue in the legacy circuit switched (CS) domain by means of SRVCC, ensuring voice service continuity. SRVCC requires the IMS. It is used in specific scenarios on LTE networks.
Benefits The service interruption period during a handover can be reduced to improve user experience with voice services.
Description To facilitate session transfer of voice services to the CS domain, the IMS multimedia telephony sessions must be implemented on the IMS. The procedure for SRVCC from E-UTRAN to UTRAN is as follows 1.
The MME receives the handover request from the E-UTRAN with the SRVCC handling indication. The MME then triggers the SRVCC procedure with the mobile switching center (MSC) server enhanced for SRVCC through the Sv interface if the MME has SRVCC STN-SR information for this UE.
2.
The MSC server enhanced for SRVCC initiates session transfer to the IMS and coordinates it with a CS handover to the target UTRAN cell.
3.
The MSC server enhanced for SRVCC sends a Forward Relocation Response message to the MME, which includes the necessary CS handover command information for the UE to access the UTRAN cell.
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The MME performs the bearer splitting function to separate the voice bearer from non-voice bearers. Then, the MME initiates a CS handover for the voice bearer to the MSC server and initiates a packet switched (PS) handover for the non-voice bearers to the serving GPRS support node (SGSN).
The MME may suppress the PS handover during the SRVCC procedure. A PS handover is performed by following the inter-RAT handover procedure defined in 3GPP TS 23.401. The MME processes the Forward Relocation Response message from the MSC server during the SRVCC and PS-PS handover procedures. Figure 2-3 shows the SRVCC from E-UTRAN to UTRAN. Figure 2-3 SRVCC from E-UTRAN to UTRAN
Enhancement None
Dependency This feature requires IMS multimedia telephony and the TDLOFD-001019 PS Inter-RAT Mobility between E-UTRAN and UTRAN feature. UEs must support SRVCC to UTRAN.
2.1.8 TDLOFD-001023 SRVCC to GERAN Availability This feature was introduced in LTE TDD eRAN2.1.
Summary SRVCC is a solution to provide voice services on LTE networks. During initial LTE network deployment, when UEs running voice services move out of an LTE network, the voice services can continue in the legacy CS domain by means of SRVCC, ensuring voice service
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continuity. SRVCC requires the IMS. It is used in specific scenarios on LTE networks. There are no commercial UEs which can support this feature.
Benefits When a UE moves from E-UTRAN to GERAN, SRVCC maintains voice call continuity for the UE.
Description When a UE moves from E-UTRAN to GERAN, SRVCC is used to maintain voice call continuity for the UE. To facilitate session transfer of voice services to the CS domain, the IMS multimedia telephony sessions must be implemented on the IMS. The procedure for SRVCC from E-UTRAN to GERAN is as follows: The MME receives the handover request from the E-UTRAN indicating SRVCC handling. The MME then triggers the SRVCC procedure with the MSC server enhanced for SRVCC through the Sv interface if the MME has SRVCC STN-SR information for this UE. The MSC server enhanced for SRVCC initiates session transfer to the IMS and coordinates it with a CS handover to the target GERAN cell. The MSC server enhanced for SRVCC sends a Forward Relocation Response message to the MME, which includes the necessary CS handover command information for the UE to access the GERAN cell. The MME performs the bearer splitting function to separate the voice bearer from non-voice bearers. The MME may suppress the PS handover during the SRVCC procedure. A PS handover is performed by following the inter-RAT handover procedure defined in 3GPP TS 23.401. The MME processes the Forward Relocation Response message from the MSC server during the SRVCC and PS-PS handover procedures. Figure 2-4 shows the SRVCC from E-UTRAN to GERAN. Figure 2-4 SRVCC from E-UTRAN to GERAN
Enhancement In eRAN8.1, the eNodeB can delete inter-frequency measurements in SRVCC to GERAN handovers.
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To facilitate the reporting of GERAN measurements and avoid call drop caused by delayed handover, the following functions are implemented:
If the VoIP service is active, all inter-frequency measurements are deleted when coverage-based GERAN measurements are started.
If the VoIP service is initiated after coverage-based GERAN measurements are started, deleting all inter-frequency measurements is triggered.
If it is detected that the VoIP service is active after coverage-based GERAN measurements are started, inter-frequency measurements are prohibited.
Dependency UEs must support SRVCC. This feature requires IMS multimedia telephony and the TDLOFD-001020 PS Inter-RAT Mobility between E-UTRAN and GERAN feature. UEs must support SRVCC to GERAN.
2.2 CSFB 2.2.1 TDLOFD-001033 CS Fallback to UTRAN Availability This feature was introduced in LTE TDD eRAN2.0.
Summary E-UTRAN cannot provide CS services. When UEs camp in an area overlapped by E-UTRAN and UTRAN coverage, this feature allows users to perform CS services.
Benefits CS services are available for users when UEs camp in an area overlapped by E-UTRAN and UTRAN coverage.
Description By using legacy CS infrastructure, this feature allows users to perform voice and other CS services (such as SMS and LCS) when UEs are served by the E-UTRAN. A CS-fallback-capable UE connected to E-UTRAN may establish one or more CS services in the UTRAN. This feature is available only when the E-UTRAN coverage and UTRAN coverage overlap. CS fallback and IMS-based services can be used simultaneously in the same operator's network. CS fallback to UTRAN requires the SGs interface between the MSC server and MME.
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Figure 2-5 Network for CS fallback to UTRAN
The MGW is not shown in Figure 2-5 because this feature does not affect user-plane processing.
Enhancement In LTE TDD eRAN6.0, the CS fallback function based on the UTRAN cell load in this feature is enhanced. eNodeBs perform CS Fallback to UTRAN based on the UTRAN cell load information, which is shared with E-UTRAN cells by using the RAN Information Management (RIM) procedure. Cell load information shared between a radio network controller (RNC) and an eNodeB is used in target cell selection for CS fallback. This increases the success rate of CS fallback to UTRAN, prevents unnecessary delay and signaling overhead, and improves user experience.
Dependency UEs must support CSFB. This feature requires TDLOFD-001019 PS Inter-RAT Mobility between E-UTRAN and UTRAN. CS fallback based on the UTRAN cell load requires the core network and RNC to support RIM-based load information transfer to E-UTRAN. This feature cannot be used with the following features:
TDLOFD-001035 CS Fallback to CDMA2000 1xRTT
TDLOFD-001090 Enhanced CS Fallback to CDMA2000 1xRTT
2.2.2 TDLOFD-001052 Flash CS Fallback to UTRAN Availability This feature was introduced in LTE TDD eRAN2.2.
Summary Flash CS fallback to UTRAN complies with 3GPP R9 specifications.
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Flash CS fallback to UTRAN can be performed when the RAN Information Management (RIM) procedure is supported by UEs, core networks, and RANs in both LTE and UMTS systems. If the networks and UEs do not support 3GPP R9 specifications, flash CS fallback to UTRAN can also be accomplished by using blind CS fallback.
Benefits This feature decreases CS service access delay to improve user experience. The delay in flash CS fallback to UTRAN is about 1 second shorter than CS fallback defined in 3GPP R8 specifications, and approximates the delay in UMTS calls.
Description The RIM procedure is accomplished with the MME and the UMTS core network, which transparently forwards the request to the target UMTS cell. Then, the target cell encapsulates the system information and sends it back to the LTE cell. The eNodeB can obtain system information for neighboring UMTS cells with the RIM procedure based on 3GPP R9 specifications. The system information can be sent to the UE during flash CS fallback so that the procedures of requesting and updating the system information can be omitted or partially omitted. As a result, the delay is reduced during CS fallback. A UE can benefit from blind CS fallback regardless of whether the UE complies with 3GPP R9 specifications. When a neighboring cell supporting blind handover has been configured for an LTE cell, blind handover significantly decreases measurement and SI access delay.
Enhancement In LTE TDD eRAN6.0, the following functions are enhanced:
Enhanced blind handover In an LTE/UMTS multimode base station, the E-UTRAN uses a different antenna system from the UTRAN. The LTE cell edge may not be included in the UMTS cell coverage. If the LTE frequency band is lower than the UMTS frequency band, the LTE cell coverage is greater than the UMTS cell coverage. In this scenario, the handover success rate for CS fallback of CEUs is low, which deteriorates user experience. To address this issue, eRAN6.0 introduces adaptive blind handover for CS fallback. Event A1 is used to distinguish between cell center users (CCUs) and CEUs. The eNodeB applies blind handovers and measurement-based handovers to CCUs and CEUs, respectively. This conserves CCU inter-RAT measurement time and increases the CSFB success rate for CEUs.
Enhanced redirection As defined in 3GPP specifications, UEs do not preferentially select a target cell whose SIBs have been delivered by the eNodeB, but instead follow general cell selection rules. If a target cell whose SIBs have been delivered by the eNodeB is selected, UEs do not need to obtain its SIBs after fallback. The greater the number of such cells, the higher the probability that flash CS fallback succeeds. However, this also increases the size of RRCConnectionRelease messages over the air interface. If the signal quality is poor, these messages may be lost. To enhance redirection for flash CS fallback in eRAN6.0, a parameter has been added to specify the maximum number of GSM cells whose SIBs can be delivered by the eNodeB
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during redirection. Operators can specify an appropriate value for this parameter based on their network performance.
Dependency The core network and UEs must support CSFB. This feature requires TDLOFD-001033 CS Fallback to UTRAN. This feature cannot be used with the following features:
TDLOFD-001035 CS Fallback to CDMA2000 1xRTT
TDLOFD-001090 Enhanced CS Fallback to CDMA2000 1xRTT
2.2.3 TDLOFD-001068 CS Fallback with LAI to UTRAN Availability This feature was introduced in LTE TDD eRAN3.0.
Summary By using the newly defined LAI IE, the eNodeB can resolve the difference between the target RATs selected by the eNodeB and MME and the selected target cells due to the discrepancy between the tracking area (TA) and (location area) LA. The optimized CS fallback process prevents unnecessary location area update (LAU) procedures and reduces the CS fallback E2E latency. If an operator only deploys LTE networks, CS fallback depends on the UMTS network deployed by other operators. The optimized CS fallback process prevents incorrect PLMN selection in such a multi-PLMN scenario.
Benefits During CS fallback from E-UTRAN to UTRAN, this feature reduces the LAU possibility, and therefore shortens the CS fallback delay due to unnecessary LAU procedures. In multi-PLMN scenarios, this feature prevents CS fallback failures due to PLMN updates.
Description In the GSM/UMTS/LTE coexistence scenario, the operator selects the combined MME/UMTS MSC attach policy when the MME receives the attach request from a GSM/UMTS/LTE or UMTS/LTE multi-mode terminal because the MME does not recognize the UE capability. The MME maintains the mapping relationships between the TA and LA. The LA belongs to the attached UMTS MSC. The MME sends the LA to the eNodeB by using the newly defined LAI IE in S1AP. When receiving the CSFB indication and location area identity (LAI), the eNodeB can select the proper RAT and neighboring cell.
Enhancement None
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Dependency UEs must support CS fallback. The core network must support the LAI IE. This feature cannot coexist with following features: TDLOFD-001035 CS Fallback to CDMA2000 1xRTT TDLOFD-001090 Enhanced CS Fallback to CDMA2000 1xRTT
2.2.4 TDLOFD-001088 CS Fallback Steering to UTRAN Availability This feature was introduced in LTE TDD eRAN6.0.
Summary Huawei eNodeBs support CS fallback steering to UTRAN based on the UE status, target RAT priorities, target UTRAN frequency priorities, and CS fallback mechanism priorities.
Benefits With this feature, operators who have deployed both an E-UTRAN and a UTRAN can achieve CS fallback of UEs to a specified RAT or inter-RAT frequency based on the network plan and load balancing requirements.
Description CS fallback steering to UTRAN can be performed based on the following configurations:
UE status, including idle (supporting CS only) and active (supporting CS and PS)
Priorities of RATs, including GERAN and UTRAN
Priorities of UTRAN frequencies, including R99 and High Speed Packet Access (HSPA)
Priorities of CS fallback mechanisms, including PS handover, PS redirection, and flash CS fallback
The preceding configurations can be modified.
Enhancement None
Dependency This feature requires the following:
TDLOFD-001033 CS Fallback to UTRAN
TDLOFD-001078 E-UTRAN to UTRAN CS/PS Steering
This feature cannot be used with the following features:
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TDLOFD-001090 Enhanced CS Fallback to CDMA2000 1xRTT
If TDLOFD-001068 CS Fallback with LAI to UTRAN is activated, CS fallback steering to UTRAN considers the LAI during target RAT selection.
2.2.5 TDLOFD-081223 Ultra-Flash CSFB to UTRAN Availability This feature is:
Available in macro eNodeBs and LampSite eNodeBs as of LTE TDD eRAN8.1.
Not available in micro eNodeBs.
Summary This feature applies to areas where UTRAN and LTE networks are deployed and LTE networks do not support VoIP services. When a UE initiates a CS service setup request in an LTE cell, this feature enables the RNC to prepare CS resources before a CS fallback through the SRVCC handover procedure. This shortens the access delay for the CS fallback and improves user experience.
Benefits This feature shortens the access delay for CS fallbacks by around 1 second and improves user experience.
Description This feature works as follows: 1.
When a UE initiates a CS service setup request in an LTE cell, the eNodeB triggers an LTE-to-UTRAN SRVCC handover.
2.
Upon identifying the proprietary SRVCC-based CS fallback procedure, the CN sends the RNC a RELOCATION REQUEST message that includes parameter indications instructing the RNC to prepare CS resources before a CS fallback.
3.
Based on the indications, the RNC prepares the required CS resources. The RNC then performs special operations to ensure that the CS fallback succeeds.
4.
After the CS fallback, the UE and CN skip the authentication and encryption procedures required by the standard CS fallback procedure.
Figure 2-6 illustrates how this feature works.
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Figure 2-6 Working principle of CSFB based on SRVCC
Enhancement None
Dependency
eNodeB None
UE UEs must support the LTE-to-UTRAN SRVCC handover procedure.
Transport Network None
CN The MME and MSC are provided by Huawei and both support this feature.
OSS None
Other Features This feature requires the following features: −
TDLOFD-001033 CS Fallback to UTRAN
Others None
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2.2.6 TDLOFD-001034 CS Fallback to GERAN Availability This feature was introduced in LTE TDD eRAN2.1.
Summary E-UTRAN cannot provide CS services. When UEs camp in an area overlapped by E-UTRAN and GERAN coverage, this feature allows users to perform CS services.
Benefits CS services are available for users when UEs camp in an area overlapped by E-UTRAN and GERAN coverage.
Description By using legacy CS infrastructure, this feature allows users to perform voice and other CS services (such as SMS and LCS) when UEs are served by the E-UTRAN. A CS-fallback-capable UE connected to E-UTRAN may establish one or more CS services in the GERAN. This feature is available only when the E-UTRAN coverage and GERAN coverage overlap. CS fallback and IMS-based services can be used simultaneously in the same operator's network. CS fallback to GERAN requires the SGs interface between the MSC server and MME. Figure 2-7 Network for CS fallback to GERAN
The MGW is not shown in Figure 2-7 because this feature does not affect user-plane processing.
Enhancement None
Dependency UEs must support CS fallback.
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This feature requires TDLOFD-001020 PS Inter-RAT Mobility between E-UTRAN and GERAN. The enhancement of CS fallback to GERAN requires support for Huawei GERAN network elements (NEs) and eCoordinator. This feature cannot be used with the following features:
TDLOFD-001035 CS Fallback to CDMA2000 1xRTT
TDLOFD-001090 Enhanced CS Fallback to CDMA2000 1xRTT
2.2.7 TDLOFD-001053 Flash CS Fallback to GERAN Availability This feature was introduced in LTE TDD eRAN2.2.
Summary Flash CS fallback to GERAN complies with 3GPP R9 specifications. Flash CS fallback to GERAN can be performed when the RIM procedure is supported by UEs, core networks, and RANs in both LTE and GSM systems. If the networks and UEs do not support 3GPP R9 specifications, flash CS fallback to GERAN can also be accomplished by using blind CS fallback.
Benefits This feature decreases CS service access delay to improve user experience. The delay in flash CS fallback to GERAN is about 2 seconds shorter than CS fallback defined in 3GPP R8 specifications, and approximates the delay in GSM calls.
Description The RIM procedure is accomplished with the MME and the GSM core network, which transparently forwards the request to the target GSM cell. Then, the target cell encapsulates the system information and sends it back to the LTE cell. The eNodeB can obtain system information for neighboring GSM cells with the RIM procedure based on 3GPP R9 specifications. The system information can be sent to the UE during flash CS fallback so that the procedures of requesting and updating the system information can be omitted or partially omitted. As a result, the delay is reduced during CS fallback. A UE can benefit from blind CS fallback regardless of whether the UE complies with 3GPP R9 specifications. When a neighboring cell supporting blind handover has been configured for an LTE cell, blind handover significantly decreases measurement and SI access delay.
Enhancement In LTE TDD eRAN6.0, the following functions are enhanced:
Enhanced blind handover In an LTE/GSM multimode base station, the E-UTRAN uses a different antenna system from the GERAN. The LTE cell edge may not be included in the GSM cell coverage. If
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the LTE frequency band is lower than the GSM frequency band, the LTE cell coverage is greater than the GSM cell coverage. In this scenario, the handover success rate for CS fallback of CEUs is low, which deteriorates user experience. To address this issue, eRAN6.0 introduces adaptive blind handover for CS fallback. Event A1 is used to distinguish between CCUs and CEUs. The eNodeB applies blind handovers and measurement-based handovers to CCUs and CEUs, respectively. This conserves CCU inter-RAT measurement time and increases the CSFB success rate for CEUs.
Enhanced redirection As defined in 3GPP specifications, UEs do not preferentially select a target cell whose SIBs have been delivered by the eNodeB, but instead follow general cell selection rules. If a target cell whose SIBs have been delivered by the eNodeB is selected, UEs do not need to obtain its SIBs after fallback. Therefore, the greater the number of such cells, the higher the probability that flash CS fallback succeeds. However, this also increases the size of RRCConnectionRelease messages over the air interface. If the signal quality is poor, these messages may be lost. To enhance redirection for flash CS fallback in eRAN6.0, a parameter has been added to specify the maximum number of GSM cells whose SIBs can be delivered by the eNodeB during redirection. Operators can specify an appropriate value for this parameter based on their network performance.
Dependency UEs must support CS fallback. This feature requires TDLOFD-001034 CS Fallback to GERAN. This feature cannot be used with the following features:
TDLOFD-001035 CS Fallback to CDMA2000 1xRTT
TDLOFD-001090 Enhanced CS Fallback to CDMA2000 1xRTT
2.2.8 TDLOFD-001069 CS Fallback with LAI to GERAN Availability This feature was introduced in LTE TDD eRAN3.0.
Summary By using the newly defined LAI IE, the eNodeB can resolve the difference between the target RATs selected by the eNodeB and MME and the selected target cells due to the discrepancy between the TA and LA. The optimized CSFB process prevents unnecessary LAU procedures and reduces the CS fallback E2E latency. If an operator only deploys LTE networks, CS fallback depends on the GSM network deployed by other operators. The optimized CS fallback process prevents incorrect PLMN selection in such a multi-PLMN scenario.
Benefits During CS fallback from E-UTRAN to GERAN, this feature reduces the LAU possibility, and therefore shortens the CS fallback delay due to unnecessary LAU procedures. In multi-PLMN scenarios, this feature prevents CS fallback failures due to PLMN updates. Issue 02 (2016-07-30)
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Description In the GSM/UMTS/LTE coexistence scenario, the operator selects the combined MME/GSM MSC attach policy when the MME receives the attach request from a GSM/UMTS/LTE or GSM/LTE multi-mode terminal because the MME does not recognize the UE capability. The MME maintains the mapping relationships between the TA and LA. The LA belongs to the attached GSM MSC. The MME sends the LA to the eNodeB by using the newly defined LAI IE in S1AP. When receiving the CSFB indication and LAI, the eNodeB can select the proper RAT and neighboring cell.
Enhancement None
Dependency UEs must support CS fallback. The core network must support the LAI IE. This feature cannot be used with the following features:
TDLOFD-001035 CS Fallback to CDMA2000 1xRTT
TDLOFD-001090 Enhanced CS Fallback to CDMA2000 1xRTT
2.2.9 TDLOFD-001089 CS Fallback Steering to GERAN Availability This feature was introduced in LTE TDD eRAN6.0.
Summary Huawei eNodeBs support CS fallback steering to GERAN based on the UE status, target RAT priorities, and CS fallback mechanism priorities.
Benefits With this feature, operators who have deployed both an E-UTRAN and a GERAN can achieve CS fallback of UEs to a specified RAT or inter-RAT frequency based on the network plan and load balancing requirements.
Description CS fallback steering to GERAN can be performed based on the following configurations:
UE status, including idle (supporting CS only) and active (supporting CS and PS)
Priorities of RATs, including GERAN and UTRAN
Priorities of CS fallback mechanisms, including PS handover, PS redirection, cell change order/network assisted cell change (CCO/NACC), and flash CS fallback
The preceding configurations can be modified.
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Enhancement None
Dependency This feature requires TDLOFD-001034 CS Fallback to GERAN. If operators require prioritization of GERAN and UTRAN frequencies for CS fallback steering, TDLOFD-001088 CS Fallback Steering to UTRAN must be activated. If TDLOFD-001069 CS Fallback with LAI to GERAN is activated, CS fallback steering to GERAN considers the LAI during target RAT selection. This feature cannot be used with the following features:
TDLOFD-001035 CS Fallback to CDMA2000 1xRTT
TDLOFD-001090 Enhanced CS Fallback to CDMA2000 1xRTT
2.2.10 TDLOFD-081203 Ultra-Flash CSFB to GERAN Availability This feature is:
Available in macro eNodeBs and LampSite eNodeBs as of LTE TDD eRAN8.1.
Not available in micro eNodeBs.
Summary When a UE initiates a voice service request in a VoIP-incapable E-UTRAN cell within the overlapping area between the E-UTRAN and a GERAN, this feature triggers a single radio voice call continuity (SRVCC) procedure to have circuit switched (CS) resources prepared in the GERAN.
Benefits This feature decreases the CS fallback (CSFB) delay by about 1.5s and improves user experience.
Description The following figure shows the procedure for ultra-flash CSFB to GERAN.
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Figure 2-8 Procedure for ultra-flash CSFB to GERAN
When the core network identifies the Huawei proprietary SRVCC procedure for CSFB, it sends the BSC a handover request message that contains CS-related parameters. As instructed by the message, the BSC prepares CS resources. Compared with standard CSFB procedures, this CSFB procedure does not require authentication, ciphering, or CS bearer setup after the UE is handed over to the GERAN. As a result, the CSFB delay decreases.
Enhancement None
Dependency
eNodeB None
UE UEs must support SRVCC from E-UTRAN to GERAN.
Transport network None
Core network MMEs and MSCs must be Huawei equipment and support ultra-flash CSFB.
OSS None
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Other features This feature requires the feature TDLOFD-001034 CS Fallback to GERAN.
Others None
2.2.11 TDLOFD-001035 CS Fallback to CDMA2000 1xRTT Availability This feature was introduced in LTE TDD eRAN6.0.
Summary E-UTRAN cannot provide CS services. When UEs camp in an area overlapped by E-UTRAN coverage and CDMA2000 1x radio transmission technology (CDMA2000 1xRTT) coverage, CS fallback to CDMA2000 1xRTT helps to provide CS services for UEs. eNodeBs support the following functions related to CS fallback:
Redirection-based CS fallback (Release 8)
Transmission and reception of short messages for UEs in the LTE network without fallback to CDMA2000 1xRTT
Benefits CS services are available for users when UEs camp in an area overlapped by E-UTRAN and CDMA2000 1xRTT coverage.
Description By using legacy CS infrastructure, this feature allows users to perform CS services when UEs are served by the E-UTRAN. A CS-fallback-capable UE connected to E-UTRAN may establish one or more CS services. This feature is available only when the E-UTRAN coverage and UTRAN coverage overlap. CS fallback and IMS-based services are available in the same operator's network. CS fallback to CDMA2000 1xRTT requires the S102 interface between the Circuit Switched Fallback Interworking Solution Function for 3GPP2 1xCS (1xCS IWS) and MME. The S102 interface provides a tunnel between the MME and the 1xCS IWS to transfer 3GPP2 1xCS signaling messages.
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Figure 2-9 Network for CS fallback to CDMA2000 1xRTT
The media gateway (MGW) is not shown in Figure 2-9 because this feature does not affect user-plane processing.
Enhancement None
Dependency The core network must support CS fallback. The 1xCS IWS must support CS fallback and enhanced CS fallback. The 1xCS IWS may be integrated into an NE, such as a CBSC newly deployed in the CDMA2000 1xRTT network. UEs must support CS fallback. This feature cannot be used with the following features:
TDLOFD-001033 CS Fallback to UTRAN
TDLOFD-001034 CS Fallback to GERAN
TDLOFD-001052 Flash CS Fallback to UTRAN
TDLOFD-001053 Flash CS Fallback to GERAN
TDLOFD-001068 CS Fallback with LAI to UTRAN
TDLOFD-001069 CS Fallback with LAI to GERAN
TDLOFD-001078 E-UTRAN to UTRAN CS/PS Steering
TDLOFD-001088 CS Fallback Steering to UTRAN
TDLOFD-001089 CS Fallback Steering to GERAN
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2.2.12 TDLOFD-001090 Enhanced CS Fallback to CDMA2000 1xRTT Availability This feature was introduced in LTE TDD eRAN6.0.
Summary If an operator has deployed a CDMA2000 1xRTT network and an E-UTRAN, UEs in the overlapping area preferentially camp in the E-UTRAN. However, the operator often requires that the CDMA2000 1xRTT network and E-UTRAN provide CS and PS services for UEs, respectively. To meet such requirements, enhanced CS fallback has been designed to ensure that UEs are handed over to the CDMA2000 1xRTT network when initiating CS services in the overlapping area.
Benefits With enhanced CS fallback, UEs can be quickly handed over from the E-UTRAN to the CDMA2000 1xRTT network to initiate or receive CS services. This quick handover improves user experience. For example, when a UE is handed over to the CDMA2000 1xRTT network to receive a CS service, the enhanced CS fallback procedure takes only 2 to 3 seconds, which is faster than the normal CS fallback procedure.
Description Enhanced CS fallback in the EPS helps to provide CS services for UEs in the E-UTRAN by reusing legacy CS infrastructures. After enhanced CS fallback to CDMA2000 1xRTT, a UE can establish one or more CS services. This feature is only available when CDMA2000 1xRTT coverage overlaps with E-UTRAN coverage. Enhanced CS fallback and IMS-based services are available in the same operator's network. Enhanced CS fallback in the EPS is implemented using the S102 interface between the 1xCS IWS and the MME. The S102 interface provides a tunnel between the MME and the 1xCS IWS to transfer 3GPP2 1xCS signaling messages. Figure 2-10 Network for enhanced CS fallback to CDMA2000 1xRTT
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The MGW is not shown in Figure 2-10 because this feature does not affect user-plane processing.
During an enhanced CS fallback procedure, the eNodeB hands over the UE to the target CDMA2000 1xRTT network to perform CS services. If the UE is performing PS services in the E-UTRAN, the eNodeB redirects the ongoing PS services to the evolved high rate packet data (eHRPD) network.
Enhancement None
Dependency This feature requires TDLOFD-001035 CS Fallback to CDMA2000 1xRTT and TDLOFD-001021 PS Inter-RAT Mobility between E-UTRAN and CDMA2000. If TDLOFD-001021 PS Inter-RAT Mobility between E-UTRAN and CDMA2000 is not enabled, enhanced CS fallback with concurrent non-optimized PS handover cannot work and other functions in TDLOFD-001090 Enhanced CS Fallback to CDMA2000 1xRTT are not affected. The CDMA2000 1xRTT network must support CS Fallback and enhanced CS fallback. NEs on the network include the 1xCS IWS, CBSC, and CBTS. The MME must support CS Fallback and enhanced CS fallback. UEs must support CS Fallback and enhanced CS fallback. If CS fallback to CDMA2000 1xRTT is enabled, eNodeBs do not support CS fallback to GERAN or CS fallback to UTRAN. If CS fallback to GERAN or UTRAN is enabled, eNodeBs do not support CS fallback to CDMA2000 1xRTT. This feature cannot be used with the following features:
TDLOFD-001033 CS Fallback to UTRAN
TDLOFD-001034 CS Fallback to GERAN
TDLOFD-001052 Flash CS Fallback to UTRAN
TDLOFD-001053 Flash CS Fallback to GERAN
TDLOFD-001068 CS Fallback with LAI to UTRAN
TDLOFD-001069 CS Fallback with LAI to GERAN
TDLOFD-001078 E-UTRAN to UTRAN CS/PS Steering
TDLOFD-001088 CS Fallback Steering to UTRAN
TDLOFD-001089 CS Fallback Steering to GERAN
2.2.13 TDLOFD-001091 CS Fallback to CDMA2000 1xRTT Based on Frequency-specific Factors Availability This feature was introduced in LTE TDD eRAN6.0.
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Summary When an operator has multiple CDMA2000 1xRTT frequencies in one or multiple band classes, this feature enables the eNodeB to transfer UEs from the E-UTRAN to the CDMA2000 1xRTT network based on the frequency-specific factors.
Benefits This feature balances the loads between CDMA2000 1xRTT frequencies.
Description An operator owning multiple CDMA2000 1xRTT frequencies can specify a circuit switched fallback (CSFB) factor for each CDMA2000 1xRTT frequency. Based on these factors, the eNodeB determines the following:
During CSFB, the eNodeB determines the target CDMA2000 1xRTT band class for redirection.
During enhanced CSFB (eCSFB), the eNodeB determines which CDMA2000 1xRTT frequency to measure. Based on the measurement results, the eNodeB hands over UEs to the CDMA2000 1xRTT network.
The operator can specify the CSFB factors for CDMA2000 1xRTT frequencies, based on their respective loads. For example, an operator has two CDMA2000 1xRTT bands: 800 MHz and 2.1 GHz. Generally, frequencies on the 800 MHz band are more heavily loaded than those on the 2.1 GHz band. To balance the loads between these two bands, the operator sets the factors for frequencies on the 800 MHz band to smaller values than those for frequencies on the 2.1 GHz band. The following figure illustrates another example. In this situation, CDMA2000 1xRTT frequencies 1, 2, and 3 are assigned factors 0.7, 1, and 1, respectively. Then the number of UEs that fall back to frequencies 1, 2, and 3 will meet the following condition: Number of UEs in frequency 1:Number of UEs in frequency 2:Number of UEs in frequency 3 = 0.7:1:1 Figure 2-11 CSFB to CDMA2000 1xRTT based on frequency-specific factors
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Enhancement None
Dependency This feature requires either of the following features:
TDLOFD-001035 CS Fallback to CDMA2000 1xRTT
TDLOFD-001090 Enhanced CS Fallback to CDMA2000 1xRTT
2.3 Increment Value Service 2.3.1 TDLOFD-001047 LoCation Services(LCS) Availability This feature was introduced in LTE TDD eRAN2.1.
Summary LCS provides a method to identify UE geographical location (such as longitude, latitude, and velocity) by using radio signal measurement.
Benefits The geographical location information can be used to offer a range of location-based value-added services. It can be used by navigation software, or for location requirements in emergency call/lawful interception situations. For example, for E911 services, the alarm center can locate the emergency call originator then conduct the appropriate rescue.
Description This feature requires the support of the Enhanced Serving Mobile Location Center (E-SMLC), which is either an independent network element in the evolved packet core (EPC) or integrated into the MME. This feature uses the following positioning methods:
Cell ID based: basic accuracy (depending on radio network density)
Observed Time Difference Of Arrival (OTDOA): medium accuracy
A-GPS: high accuracy
LCS is implemented mainly on the E-SMLC and UE while the eNodeB acts as a transparent entity for messages and information measurement forwarding. A typical LCS procedure is as follows: 1.
The MME receives an LCS request for a target UE location, or the MME starts LCS service independently.
2.
The MME sends the LCS request to the E-SMLC.
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3.
The E-SMLC sends additional data to the UE and checks the related measurement information from the UE or eNodeB. The E-SMLC calculates the location information for the target UE and forwards the information to the MME.
4.
If the MME does not host the LCS, the MME will forward the location information to the NE that hosts the LCS.
Enhancement None
Dependency UEs must support LCS for A-GPS and OTDOA. OTDOA requires time synchronization for the E-UTRAN. The MME must support the (LTE Positioning Protocol A) LPPa protocol. The E-SMLC is required.
2.3.2 TDLOFD-001092 CMAS Support Availability This feature was introduced in LTE TDD eRAN6.0.
Summary This feature enables eNodeBs to support the commercial mobile alert system (CMAS). When disasters or other emergencies occur, eNodeBs will receive warning broadcast requests from MMEs, and then promptly send warning notifications to UEs in RRC_CONNECTED and RRC_IDLE mode using system information (SI) broadcast. This allows people to use their mobile phones to learn about potential threats as soon as possible.
Benefits This feature offers the following benefits:
Helps mitigate damage by alerting people of disasters or emergencies more quickly than other forms of communication.
Allows operators to fulfill their social responsibilities for helping protect users from harm, and improves the social reputation of the operators. This feature complies with all laws and regulations where it is employed.
Description CMAS implements the following functions:
Supports requests for starting and stopping CMAS warning notification broadcasts. This feature supports Write-Replace Warning messages and Kill messages defined in 3GPP S1 Application Protocol (S1AP) specifications. CMAS warning notifications can be broadcast for a specified number of times at a specified interval.
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Manages priorities of multiple CMAS warning broadcast tasks.
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If there are multiple CMAS warning broadcast tasks, an eNodeB adjusts the priorities of these tasks based on their individual broadcast intervals and number of broadcast times. This ensures broadcast fairness among all tasks. The eNodeB can manage a maximum of 64 CMAS broadcast tasks simultaneously. This feature requires the support of the E-SMLC.
Enhancement None
Dependency UEs must support CMAS. The MME in the EPC must support CMAS.
2.3.3 TDLOFD-081222 Dynamic Service-specific Access Control Availability This feature is:
Available in macro eNodeBs as of LTE TDD eRAN8.1.
Available in micro eNodeBs as of LTE TDD eRAN8.1.
Available in LampSite eNodeBs as of LTE TDD eRAN8.1.
Summary This feature performs access class (AC) control on users who initiate multimedia telephony video or voice services, based on cell congestion and disaster states.
Benefits In the case of disasters, users may frequently use multimedia telephony video or voice services to contact their relatives. This consumes most of the radio resources, and as a result, other users cannot use the disaster message board service through the PS network to obtain the disaster-related information and evacuation advisories in real time. In addition, other users cannot use the short message service (SMS) to contact their relatives. This feature prohibits some users from accessing a congested cell when these users initiate multimedia telephony video or voice services in the case of disasters. This ensures that other users can access the disaster message board through the PS network or contact their relatives using SMS in real time.
Description This feature performs AC control on users who initiate multimedia telephony video or voice services, based on cell congestion and disaster states. The feature is triggered based on the following factors:
Disaster state The eNodeB determines that a disaster occurs upon receiving a primary notification of the earthquake and tsunami warning system (ETWS) or a warning notification from the
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commercial mobile alert system (CMAS). Reference notifications can be set using parameters.
Cell congestion state The eNodeB identifies the cell congestion state based on the current flow control level of the cell. The specific policies are as follows: −
If the condition for triggering AC control is met throughout a specific number of consecutive measurement periods after a disaster occurs in a congested cell, the eNodeB performs AC control on users who initiate multimedia telephony video or voice services.
−
If the cell is still in the disaster state and the cell does not meet the conditions for canceling AC control in any measurement period after AC control is triggered, the eNodeB gradually increases the proportion of users under AC control.
−
After AC control is triggered, the eNodeB periodically checks the cells status. If the cell is not in a disaster or congestion state for a period shorter than the threshold period for canceling AC control, the eNodeB retains the proportion of users under AC control and continues AC control on users who initiate multimedia telephony video or voice services.
−
After AC control is triggered, if the cell exits the disaster state or meets the condition for canceling AC control throughout a specified number of consecutive measurement periods, the eNodeB gradually cancels AC control on users who initiate multimedia telephony video or voice services.
Enhancement In eRAN11.1, the access probability factor adjustment step is configurable.
Dependency
eNodeB None
UE UEs must support AC control on multimedia telephony video or voice services defined in 3GPP Release 9.
Transport network None
Core network None
OSS None
Other features This feature requires TDLBFD-002009 Broadcast of system information.
Others None
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2.3.4 TDLOFD-070220 eMBMS Phase 1 based on Centralized MCE Architecture Availability This feature is:
Available in macro eNodeBs as of LTE TDD eRAN7.0.
Available in micro eNodeBs as of LTE TDD eRAN8.0.
Available in LampSite eNodeBs as of LTE TDD eRAN7.0.
Summary Huawei evolved multimedia broadcast/multicast service (eMBMS) phase 1 supports transmission of MBMS services based on the centralized multi-cell/multicast coordination entity (MCE) architecture, which is defined in 3GPP Release 9.
Benefits When operators provide unicast services and there is a large demand for services (for example, live video of a football match) in an LTE network, eMBMS offers the following benefits:
A stable and bandwidth-guaranteed broadcast offers a satisfactory service experience. There is no limit on the number of UEs that receive MBMS services, because MBMS services are broadcast using semi-static radio resource configurations and the number of UEs served does not match the amount of resources allocated. Either RRC_IDLE or RRC_CONNECTED UEs can receive MBMS services. There is no limit on the number of RRC_IDLE UEs that receive MBMS services. However, the maximum number of RRC_CONNECTED UEs that receive MBMS services is subject to the cell capacity expressed in a number of UEs.
The broadcast allows resources to be shared in order to deliver the services in demand. It reduces the requirement for unicast bearer resources and lowers the risk of network congestion. In addition, it improves user experience with existing unicast services in a heavily loaded or even congested network.
eMBMS reduces investment in equipment for capacity expansion and allows operators to develop new value-added services (for example, high-definition video) in order to increase revenue.
Description Compared with the LTE-SAE architecture that supports unicast services, an eMBMS-supporting LTE network architecture introduces three new network elements (NEs): Broadcast multicast service center (BM-SC): supports service announcement, security management, session management, transmission proxy, and data synchronization. eMBMS gateway (MBMS GW): forwards MBMS user-plane data to the eNodeB using IP multicast over the M1 interface and performs MBMS session control through the MME. The MBMS GW can be deployed together with the P-GW. MCE: provides control-plane functions, such as admission control on MBMS sessions, and time-frequency resource allocation for Multimedia Broadcast multicast service Single Frequency Network (MBSFN) transmission by all eNodeBs in a single MBSFN area. Issue 02 (2016-07-30)
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In Huawei eMBMS phase 1, the MCE is deployed as a standalone physical entity. An eCoordinator, rather than the eNodeB, provides the MCE functionality. Figure 2-12 shows the network architecture for Huawei eMBMS phase 1. Figure 2-12 Network architecture of Huawei eMBMS phase 1
In eRAN7.0, Huawei eMBMS phase 1 supports subframe configurations 1 and 2, and the bandwidths supported by Huawei eMBMS phase 1 are as follows:
Macro eNodeBs: 10 MHz, 15 MHz, and 20 MHz
Micro eNodeBs: 10 MHz and 20 MHz
eRAN8.0
Enhancement Since LTE TDD eRAN8.0, Huawei eMBMS supports MBSFN area overlaps. A single cell can belong to a maximum of three MBSFN areas. The support of MBSFN area overlaps enables more flexible deployment of MBMS services, especially when some services must be transmitted across a wide area and some other services only at hotspot locations. For MBSFN area overlaps, Huawei eMBMS supports the following subfunctions: −
Configuring the mapping between a single cell and multiple MBSFN areas on the MCE
−
Allocating MBSFN subframes in a centralized manner in overlapping MBSFN areas
At the startup of an MBMS session, the MCE chooses the MBSFN area where the session is to be delivered. If overlapping MBSFN areas exist in the target region for session delivery, the MCE chooses the largest MBSFN area that meets the MBMS service area requirement of the session, and then performs centralized allocation of MBSFN subframes for cells in the chosen MBSFN area.
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eRAN11.0 −
eMBMS can be implemented in RAN sharing scenarios. In scenarios of RAN sharing with common carriers, RAN sharing with dedicated carriers, or hybrid RAN sharing, different operators can provide their own eMBMS services in the shared network. In the case of multi-operator core network (MOCN), eNodeBs/MCEs can connect to each of the operators' evolved packet cores (EPCs) through a dedicated M3/M1 interface. In this way, operators can use their own EPCs to set up and control their specific eMBMS services. In the case of RAN sharing with common carriers, the MCE supports the configuration of the proportion of resources available for each operator.
−
eMBMS supports the MME pool networking mode. The MCE can connect to each MME in an MME pool through a dedicated M3 interface.
−
If an MME controlling a specific MBMS session becomes faulty, the MCE cooperates with the EPC to enable another MME in the same MME pool to control
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the session. This mechanism ensures normal running of MBMS sessions in case of MME failures and improves the eMBMS reliability.
Dependency
eNodeB The LBBPc and LMPT do not support this feature.
eCoordinator The eCoordinator must be deployed to provide the MCE functionality.
Core network This feature requires core network elements such as the BM-SC, MBMS-GW and MBMS-supporting MMEs.
UE UEs must support this feature.
Transport network The M1, M2, and M3 interfaces must be configured for this feature.
Other features This feature requires TDLBFD-00300503 Synchronization with GPS or TDLOFD-00301302 IEEE1588 V2 Clock Synchronization.
Others This feature requires time synchronization with the accuracy of ±1.5 µs.
2.3.4.1 TDLOFD-07022001 Multi-cell transmission in MBSFN area Availability This feature is
applicable to Macro from LTEeRAN7.0
applicable to Micro from eRAN8.0
applicable to LampSite from eRAN7.0
Summary This feature enables the multi-cell/multicast coordination entity (MCE) to allocate the same radio resources to all cells within a multimedia broadcast multicast service single frequency network (MBSFN) area and also enables the cells to use the same time-frequency resources to transmit the same multimedia broadcast multicast service (MBMS) sessions.
Benefits This feature ensures synchronization of radio resources configurations between the cells within an MBSFN area and the continuous coverage of evolved MBMS (eMBMS) services within the MBSFN area, reducing interference between the cells within the MBSFN area.
Description All cells within an MBSFN area use the same radio resources and modulation and coding scheme (MCS) to transmit the same MBMS sessions. If MBMS user data is synchronized, the
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MCE sends MBMS Scheduling Information messages to eNodeBs to ensure synchronization of MBSFN subframes allocated to the cells, increasing MBSFN gains.
Enhancement None
Dependency The dependency of this feature is the same as that of TDLOFD-070220 eMBMS Phase 1 based on Centralized MCE Architecture.
2.3.4.2 TDLOFD-07022002 Mixed transmission of unicast and broadcast Availability This feature is
applicable to Macro from LTEeRAN7.0
applicable to Micro from eRAN8.0
applicable to LampSite from eRAN7.0
Summary This feature supports mixed transmission of broadcast and unicast services in cells based on time division multiplexing.
Benefits This feature maximizes radio resource usage in cells within a multimedia broadcast multicast service single frequency network (MBSFN) area based on the dynamic MBSFN subframe allocation. MBSFN subframes can be dynamically allocated based on the multimedia broadcast multicast service (MBMS) session requirements.
Description Broadcast and unicast services can be transmitted in the same radio frame based on time division multiplexing. As shown in Figure 2-13, MBSFN subframes transmit broadcast services and normal subframes transmit unicast services.
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Figure 2-13 MBSFN subframes
In an LTE FDD system, a maximum of six subframes in one radio frame can be configured as MBSFN subframes for eMBMS. In an LTE TDD system, if uplink-downlink subframe configuration 5 is used, a maximum of five subframes in one radio frame can be configured as MBSFN subframes for eMBMS. In Huawei eMBMS solution, MBSFN subframes are dynamically configured to meet MBMS session requirements. As a result, a radio frame consists of both MBSFN subframes and normal subframes.
Enhancement None
Dependency None
2.3.4.3 TDLOFD-07022003 Data synchronization Availability This feature is
applicable to Macro from LTE TDD eRAN7.0
applicable to Micro from LTE TDD eRAN8.0
applicable to LampSite from LTE TDD eRAN7.0
Summary Multimedia broadcast multicast service (MBMS) user data is synchronized in compliance with the SYNC protocol.
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Benefits This feature complies with 3GPP specifications and is fundamental to eMBMS.
Description MBSFN transmission from multiple cells requires not only frequency and phase synchronization but also MBMS user data synchronization between the cells. Data synchronization is stipulated in the SYNC protocol. For details, see 3GPP TS 25.446. A SYNC protocol data unit (PDU) consists of different fields, depending on the PDU type. Among the fields, the timestamp and packet number are included in SYNC PDUs of all types. The timestamp helps ensure that cells in MBSFN transmission send the same MBMS session at the same time. The packet number is used to detect packet loss, check the packet sequence, and rearrange SYNC PDUs if the received PDUs are out of sequence. Huawei eMBMS solution supports SYNC PDUs of types 0, 1 and 3. Data synchronization requires that the eNodeB and broadcast multicast service center (BM-SC) be configured with the same synchronization period, synchronization start time, and synchronization end time. The synchronization period is an integer multiple of 1024 radio frames and must be less than 10 minutes. In the eNodeB, the integer multiple of 1024 radio frames is specified by the eNodeB-level parameter SyncPeriod in the MBMSPara MO. This parameter is set to 58 by default, which represents a synchronization period of 593920 ms.
Enhancement None
Dependency The dependency of this feature is the same as that of TDLOFD-070220 eMBMS Phase 1 based on Centralized MCE Architecture.
2.3.4.4 TDLOFD-07022004 Session admission control Availability This feature is
applicable to Macro from LTE TDD eRAN7.0
applicable to Micro from LTE TDD eRAN8.0
applicable to LampSite from LTE TDD eRAN7.0
Summary The multi-cell/multicast coordination entity (MCE) performs admission control on multimedia broadcast multicast service (MBMS) sessions initiated by the MME.
Benefits This feature protects the network against congestion or even collapse caused by excessive eMBMS sessions while maximizing the radio resource usage for eMBMS services and maintaining the optimum quality of service (QoS) satisfaction rate of eMBMS services.
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Description Cells within a multimedia broadcast multicast service single frequency network (MBSFN) area are configured with the same radio resources, and the MCE performs admission control on MBMS sessions in the cells. The MME initiates an MBMS session by sending an MBMS Session Start Request message to the MCE that controls the eNodeBs in the targeted MBMS service area. The message contains information elements (IEs) MBMS Service Area and MBMS E-RAB QoS parameters. The MCE performs admission control the MBMS session based on the IEs. If the available MBSFN subframes are insufficient for the MBMS session in all MBSFN areas under the MBMS service area, the MCE rejects the MBMS session request. If the available MBSFN subframes in one MBSFN area supports the MBMS session, the MCE accepts the MBMS session request. However, only the available MBSFN subframes in this MBSFN area are used to transmit the MBMS session. The MBSFN subframes in the other MBSFN areas are used to transmit the MBMS session only when the MBSFN subframes in these MBSFN areas are sufficient for the MBMS session transmission.
Enhancement None
Dependency None
2.3.5 TDLOFD-080210 eMBMS Service Continuity Availability This feature is
Applicable to macro and LampSite eNodeBs from LTE TDD eRAN8.1.
Not applicable to micro eNodeBs.
Summary This feature is an enhancement to the evolved multimedia broadcast/multicast service (eMBMS) feature for service continuity according to 3GPP Release 11. When this feature is activated, UEs can identify MBMS services transmitted at different frequencies in an inter-frequency networking scenario. Based on the information provided by a UE about the MBMS service that the UE is interested in, the network formulates an appropriate frequency camping policy for the UE. Based on this policy, the UE can switch to the right frequency for reception of the desired MBMS service.
Benefits This feature improves user experience with MBMS services.
Description The serving cell of a UE broadcasts all the E-UTRA absolute radio frequency channel numbers (EARFCNs) and MBMS service area IDs (SAIs) used on the current network. After Issue 02 (2016-07-30)
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receiving the information, a UE identifies the target frequency used to transmit the MBMS service that the UE is interested in. If in idle mode, the UE directly switches to the target frequency by cell reselection to receive the desired MBMS service. If in connected mode, the UE informs the serving eNodeB about the target frequency at which its desired MBMS service is transmitted, and the eNodeB determines whether to immediately hand over the UE to the target frequency.
Enhancement None
Dependency
UE UEs must comply with 3GPP Release 11.
Other features This feature requires TDLOFD-070220 eMBMS Phase 1 based on Centralized MCE Architecture.
2.4 Video Service Optimization 2.4.1 TDLOFD-111205 Busy-Hour Download Rate Control Availability This feature is:
Available in macro eNodeBs as of LTE TDD eRAN11.1.
Available in micro eNodeBs as of LTE TDD eRAN11.1.
Available in LampSite eNodeBs as of LTE TDD eRAN11.1.
Summary This feature restricts the data rates of downloading services during busy hours.
Benefits This feature reduces the resource consumption of downloading services and spares air interface resources for high-priority services.
Description Downloading services are identified through the core network or the service awareness device of a third-party. The identified results are labeled on the differentiated services code points (DSCPs) of service packets. The eNodeB identifies these DSCPs and performs differentiated scheduling based on preset QoS configurations such as priority and service maximum bit rate (SMBR). When the data rates of downloading services exceed the configured SMBR, the eNodeB lowers the scheduling priority of downloading services to decrease the resources occupied by such services.
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Enhancement None
Dependency
eNodeB None
UE None
Transport network None
Core network None
OSS None
Others A service awareness device is required.
2.4.2 TDLOFD-111206 Video Service Rate Adaption Availability This feature is:
Available in macro eNodeBs as of LTE TDD eRAN11.1.
Available in micro eNodeBs as of LTE TDD eRAN11.1.
Available in LampSite eNodeBs as of LTE TDD eRAN11.1.
Summary This feature is applicable to initial video acceleration and service rate guarantee.
Benefits
Reduced video waiting time, which improves user experience in opening a video
Guaranteed video playing rate, which avoids video play suspension
Description Video services are identified through the core network or the service awareness device of a third-party. The identified results are labeled on the differentiated services code points (DSCPs) of service packets. The eNodeB identifies these DSCPs and performs differentiated scheduling based on preset QoS configurations such as priority, service guaranteed bit rate (SGBR), and segment acceleration policy. When the data rates of video services are lower than the configured SGBR during video playback, the eNodeB raises the scheduling priority of video services. If the data rates satisfy the SGBR requirements, the eNodeB does not adjust the scheduling priority.
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If the segment acceleration policy is configured, a higher priority and a higher SGBR rate are adopted to guarantee video services during the initial phase for video services to increase the initial video download rate. The initial phase for video services is configurable.
Enhancement None
Dependency
eNodeB None
UE None
Transport network None
Core network None
OSS None
Others A service awareness device is required.
2.4.3 TDLOFD-110225 Uplink Data Compression Availability This feature is: Available in macro eNodeBs as of LTE TDD eRAN11.1. Available in micro eNodeBs as of LTE TDD eRAN11.1. Available in LampSite eNodeBs as of LTE TDD eRAN11.1.
Summary When the uplink data compression (UDC) feature is enabled, a UDC-capable UE only sends seldom-repeated data among raw data on an uplink channel over the air interface. This feature reduces the amount of uplink data over the air interface and increases the amount of application layer data that can be transmitted using a given amount of air interface resources, improving the uplink application layer transmission rate.
Benefits With a given transmission quality of air interface channels and physical resource block (PRB) usage over the air interface, this feature considerably improves the uplink application layer transmission rate.
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Description A UE compresses the original user plane data packets to be sent, buffers the data to be sent for the first time, and instructs the eNodeB to buffer the same data. Afterwards, the UE filters out the repeated data that is already buffered, from the raw data to be sent over the air interface in the uplink. Repeated data includes HTTP GET, TCP ACK, and TCP/UDP/IP packet headers. As a replacement of this data after buffering, new information is added to the UDC header for transmission, including the repeated data storage indication, decompression indication, location of repeated data in the buffer, and location of repeated data in the complete data packets after decompression. After receiving data packets from the UE, the eNodeB decompresses the packets based on the information in the UDC header to retrieve the complete packets. The UDC algorithm can be used for data streams transmitted in acknowledged mode (AM) on the Radio Link Control (RLC) layer.
Enhancement None
Dependency
eNodeB This feature can be used on macro, micro, and LampSite eNodeBs. The BBP model can not be LBBPc.
eCoordinator None
Core network None
UE The feature requires support from UEs.
Transport network None
Other features None
Others None
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3
Radio & Performance
3.1 2-layer Mutil-Antenna 3.1.1 TDLOFD-001001 DL 2x2 MIMO Availability This feature was introduced in LTE TDD eRAN1.0.
Summary Huawei LTE TDD eRAN1.0 supports DL 2x2 multiple-input multiple-output (MIMO), 2-antenna transmit diversity, and adaptive MIMO schemes between UEs and eNodeBs, improving system downlink performance.
Benefits This feature significantly improves downlink system throughput and coverage performance and also provides good user experience by offering higher data rates.
Description The downlink 2x2 MIMO is critical to the LTE outperforming the legacy system. Both space diversity and spatial multiplexing are supported as defined in LTE specifications. Huawei eNodeBs support two DL 2x2 MIMO modes:
Transmit diversity
Open-loop spatial multiplexing
If two transmit antennas are configured for the eNodeB, the eNodeB adaptively selects one of the two modes based on the UE rate and downlink channel quality. Transmit diversity is a solution to mitigate signal fading and interference. By providing several signal branches that present independently varying signal levels, the robustness of the radio link creates a low probability that all signal copies are simultaneously in deep fading. Spatial multiplexing is a technique to transmit independent and separately encoded data signals, known as streams, from each of the transmit antennas that results in the space dimension being reused, or multiplexed. If the transmitter is equipped with Ntx antennas and the receiver has Nrx antennas, the maximum spatial multiplexing order is Ns = min (Ntx, Nrx). Issue 02 (2016-07-30)
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If the spatial channels are independent of each other (that is, Ns different data streams are transmitted over several independent spatial channels), it leads to an Ns increase of the spectrum efficiency or capacity.
Enhancement None
Dependency The eNodeB must be configured with two transmit channels and two antennas per sector, and the UE must be configured with a minimum of two antennas for receiving.
3.1.2 TDLOFD-001030 Support of UE Category 2/3/4 Availability This feature was introduced in LTE TDD eRAN2.0.
Summary An eNodeB must obtain the signaled UE radio access capability parameters when configuring and scheduling the UE. There are five categories defined in the protocol. When this feature is enabled, eNodeBs support UE categories 2, 3, and 4.
Benefits eNodeBs support UE categories 2, 3, and 4.
Description Table 3-1 Downlink physical layer parameter values in the ue-Category field UE Category
Maximum Number of DL-SCH Transport Block Bits Received Within a TTI
Maximum Number of Bits of a DL-SCH Transport Block Received Within a TTI
Total Number of Soft Channel Bits
Maximum Number of Supported Layers for DL Spatial Multiplexing
Category 1
10296
10296
250368
1
Category 2
51024
51024
1237248
2
Category 3
102048
75376
1237248
2
Category 4
150752
75376
1827072
2
Category 5
299552
149776
3667200
4
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Table 3-2 Uplink physical layer parameter values in the ue-Category field UE Category
Maximum Number of Bits of an UL-SCH Transport Block Transmitted Within a TTI
Support for UL 64QAM
Category 1
5160
No
Category 2
25456
No
Category 3
51024
No
Category 4
51024
No
Category 5
75376
Yes
Table 3-3 Total layer-2 buffer sizes in the ue-Category field UE Category
Total Layer-2 Buffer Size (Kbytes)
Category 1
150
Category 2
700
Category 3
1400
Category 4
1900
Category 5
3500
Enhancement None
Dependency UEs must support the same category as eNodeBs.
3.1.3 TDLOFD-001049 Single Streaming Beamforming Availability This feature is
Applicable to macro eNodeBs from LTE TDD eRAN2.1.
Not applicable to LampSite eNodeBs.
Not applicable to micro eNodeBs.
Summary This feature provides good user experience by offering higher data rates.
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Benefits This feature can significantly improve the system throughput (especially for CEUs) and coverage performance in the uplink and downlink.
Description The classical technique of using an antenna array for transmitting energy in the direction of the intended receiver falls into the category of improving SINR. Beamforming achieves increased SINR by adjusting the phase of signals transmitted on different antennas with the aim of making the signals add-up constructively on the receiver. Huawei LTE TDD eRAN2.1 provides support on DL 8x2 and DL 4x2 Beamforming.
Enhancement None
Dependency The eNodeB must be configured with a minimum of four antennas for transmission. This feature cannot be used in the LampSite solution. This feature does not apply to micro eNodeBs. UEs must support transmission mode 7 (TM7) for single streaming beamforming, which is defined in 3GPP Release 8 specifications. This feature does not work when the eNodeB bandwidth is 5 MHz. This feature cannot be used with the following features:
TDLOFD-001031 Extended CP
TDLOFD-001007 High Speed Mobility
3.1.4 TDLOFD-001061 Dual Streaming Beamforming Availability This feature is
Applicable to macro eNodeBs from LTE TDD eRAN2.1.
Not applicable to LampSite eNodeBs.
Not applicable to micro eNodeBs.
Summary In LTE TDD eRAN2.2, the eNodeB supports dual-stream beamforming for 3GPP Release 9 compliant UEs. In dual-stream beamforming mode, two data streams are transmitted on the same OFDM time-frequency resource. The eNodeB adaptively selects single- or dual-stream beamforming based on UE capabilities and channel conditions to increase downlink throughput.
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Benefits This feature significantly increases downlink throughput and improves user experience.
Description 3GPP Release 9 specifications define TM8, a new beamforming transmission mode, that supports dual-stream beamforming. In dual-stream beamforming mode, two different and independently coded data streams are separately transmitted from two logical antenna ports. Either of the two data streams is generated by four or eight antennas in beamforming transmission mode. The two data streams both form directional beams towards the target UE, which increases the SINR. Dual-stream beamforming incorporates both spatial multiplexing and beamforming during downlink transmission. This helps provide partial multiplexing gains, diversity gains, and array gains.
Enhancement None
Dependency The eNodeB must be configured with a minimum of four antennas for transmission. UEs must be configured with a minimum of two antennas for receiving and must support TM8 for dual stream beamforming, which is defined in 3GPP Release 9 specifications. This feature does not apply to micro eNodeBs. This feature requires TDLOFD-001049 Single Streaming Beamforming. This feature cannot be used with the following features:
TDLOFD-001031 Extended CP
TDLOFD-001007 High Speed Mobility
This feature cannot be used in the LampSite solution. This feature does not work when the eNodeB bandwidth is 5 MHz.
3.1.5 TDLOFD-001077 MU-Beamforming Availability This feature is
Applicable to macro eNodeBs from LTE TDD eRAN3.0.
Not applicable to LampSite eNodeBs.
Not applicable to micro eNodeBs.
Summary In LTE TDD eRAN3.0, eNodeBs support 3GPP Release 9-compliant TM8. In TM8, two DM-RS sequences are orthogonal with each other and are transmitted separately over antenna ports 7 and 8. When these DM-RS sequences are allocated to two UEs, one sequence is transmitted over antenna port 7 for one UE and the other sequence over antenna port 8 for the
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other UE. In this situation, two data streams are transmitted separately to two UEs using the same OFDM time-frequency resources. The eNodeB determines the UEs for pairing based on UE pairing conditions, thereby increasing the downlink throughput. In LTE TDD eRAN8.1, the following UEs can be paired for MU beamforming:
UE using antenna port 7 in TM8 + UE using antenna port 8 in TM8
UE in TM7 + UE in TM9
When both of the paired UEs support TM8 or TM9, one of the UEs uses antenna port 7 to receive orthogonal DM-RS sequences and the other UE uses antenna port 8 to receive the sequences. When two UEs in TM7 are paired, both of these UEs receive DM-RSs over antenna port 5. When one UE in TM7 is paired with another UE in TM8 or TM9, the UE in TM7 receives DM-RSs over antenna port 5 and the other UE over antenna port 7 or 8. In this situation, two data streams are transmitted separately to two UEs using the same OFDM time-frequency resources. The eNodeB determines UEs for pairing based on UE pairing conditions.
Benefits This feature increases the downlink throughput and improves user experience.
Description TM8 has been introduced since 3GPP Release 9, which enables eNodeBs to support dual-stream beamforming. In TM8, two independently encoded data streams are transmitted over different antenna ports after being scrambled using two orthogonal DM-RS sequences. When two UEs in TM8 work in single-stream beamforming mode, each UE uses one antenna port. When these two UEs meet UE pairing conditions, the eNodeB generates two orthogonal beams based on the zero forcing principles, and then pairs these two UEs. MU beamforming increases the spectral efficiency in the downlink by using spatial multiplexing.
Enhancement In LTE TDD eRAN8.1, the following UEs can be paired for MU beamforming:
UE using antenna port 7 in TM8 + UE using antenna port 8 in TM8
UE in TM7 + UE in TM9
When both of the paired UEs support TM8 or TM9, one of the UEs uses antenna port 7 to receive orthogonal DM-RS sequences and the other UE uses antenna port 8 to receive the sequences. When two UEs in TM7 are paired, both of these UEs receive DM-RSs over antenna port 5. When one UE in TM7 is paired with another UE in TM8 or TM9, the UE in TM7 receives DM-RSs over antenna port 5 and the other UE over antenna port 7 or 8. In this situation, two data streams are transmitted separately to two UEs using the same OFDM time-frequency resources. The eNodeB determines UEs for pairing based on UE pairing conditions.
Dependency The eNodeB must have at least four transmit antennas. This feature requires TDLOFD-001049 Single Streaming Beamforming.
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To use adaptation between single-stream beamforming and dual-stream beamforming, the UE must support TM7, TM8, or TM9. This feature cannot be used when the channel bandwidth is 5 MHz. This feature does not work with the following features:
TDLOFD-001031 Extended CP
TDLOFD-001007 High Speed Mobility
This feature does not apply to LampSite eNodeBs or BTS3205E. The LBBPc does not support this feature.
3.1.6 TDLOFD-001005 UL 4-Antenna Receive Diversity Availability This feature is
Applicable to macro eNodeBs from LTE TDD eRAN2.1.
Not applicable to LampSite eNodeBs.
Not applicable to micro eNodeBs.
Summary Receive diversity is a common type of multiple-antenna technology to improve signal reception and to mitigate signal fading and interference. It improves network capacity and data rates. In addition to UL 2-antenna receive diversity, Huawei eNodeBs also support 4-antenna receive diversity.
Benefits This feature improves uplink coverage and throughput.
Description Receive diversity is a technique to mitigate signal fading and interference. Multiple frequencies may be monitored from the same signal source or the same frequency may be monitored from multiple antennas. Receive diversity is a way to enhance uplink channel reception, including the PUSCH, physical uplink control channel (PUCCH), physical random access channel (PRACH), and sounding reference signal (SRS). Huawei eNodeBs can work with or without RX diversity. In RX diversity mode, Huawei eNodeBs in LTE TDD eRAN2.1 can be configured with 4 antennas (4-way) by setting the antenna magnitude in addition to UL 2-antenna receive diversity.
Enhancement None
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Dependency This feature requires eNodeBs to provide enough RF channels and demodulation resources to match the number of diversity antennas. This feature cannot be used in the LampSite solution. This feature does not apply to micro eNodeBs. This feature does not work when the bandwidth of the eNodeB equipped with the LBBPc is 5 MHz.
3.1.7 TDLOFD-001058 UL 2x4 MU-MIMO Availability This feature is:
Available in macro eNodeBs as of LTE TDD eRAN2.2.
Not available in micro eNodeBs.
Not available in LampSite eNodeBs.
Summary This feature allows a maximum of two UEs to share the same time-frequency resource.
Benefits This feature increases cell throughput in the uplink.
Description When an eNodeB is equipped with four receive antennas, it can use uplink 2x4 MU-MIMO to improve uplink performance. The eNodeB can adaptively switch between uplink 2x4 MU-MIMO and uplink 4-antenna receive diversity. If the uplink CQI of a UE is high or the orthogonality between the uplink channels of this UE and other UEs is high, the eNodeB uses uplink 2x4 MU-MIMO to improve uplink performance; otherwise, the eNodeB uses 4-antenna receive diversity. This feature can be used only with the PUSCH.
Enhancement In LTE TDD eRAN8.1, this feature enables the eNodeB to select UEs that can achieve the highest throughput for pairing. In addition, enhanced MU-MIMO allows the eNodeB to schedule UEs with high SINRs and UEs with low SINRs at different ends of the frequency band to reduce interference between them. The eNodeB allocates the same time-frequency resource to paired UEs. The following functions are introduced in LTE TDD eRAN11.0:
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MCS index decrease and RB number increase for UEs with a small amount of data, increasing the UE pairing probability
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MU-MIMO for VoLTE UEs, increasing the UE pairing probability and the VoLTE UE capacity
Dependency The eNodeB must provide four receive antennas in each cell. This feature requires the following features:
TDLOFD-001015 Enhanced Scheduling
TDLOFD-001005 UL 4-Antenna Receive Diversity
TDLOFD-001094 Control Channel IRC
When the LBBPc is used, this feature is not compatible with the following features:
TDLOFD-001075 SFN
TDLOFD-002008 Adaptive SFN/SDMA
TDLOFD-001098 Inter-BBP SFN
TDLOFD-001080 Inter-BBU SFN
TDLOFD-001081 Inter-BBP Adaptive SFN/SDMA
TDLOFD-001082 Inter-BBU Adaptive SFN/SDMA
3.1.8 TDLOFD-001062 UL 8-Antenna Receive Diversity Availability This feature is:
Available in macro eNodeBs as of LTE TDD eRAN2.1.
Not available in micro eNodeBs.
Not available in LampSite eNodeBs.
Summary Receive diversity is a common type of multiple-antenna technology to improve signal reception and to mitigate signal fading and interference. It improves network capacity and data rates. In addition to UL 2-antenna and UL 4-antenna receive diversity, Huawei eNodeBs also support 8-antenna receive diversity.
Benefits This feature improves uplink coverage and throughput.
Description Receive diversity is a technique to mitigate signal fading and interference. Multiple frequencies may be monitored from the same signal source or the same frequency may be monitored from multiple antennas. Receive diversity is a way to enhance uplink channel reception, including the PUSCH, physical uplink control channel (PUCCH), physical random access channel (PRACH), and sounding reference signal (SRS).
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Huawei eNodeBs can work with or without RX diversity. In RX diversity mode, Huawei eNodeBs in LTE TDD eRAN2.1 can be configured with 8 antennas (8-way) through the antenna magnitude in addition to UL 2-antenna and 4-antenna receive diversity.
Enhancement None
Dependency This feature requires eNodeBs to provide enough RF channels and demodulation resources to match the number of diversity antennas. This feature requires TDLOFD-001005 UL 4-Antenna Receive Diversity. This feature cannot be used in the LampSite solution. This feature does not apply to micro eNodeBs. This feature does not work when the eNodeB bandwidth is 5 MHz.
3.1.9 TDLOFD-081205 UL 2x8 MU-MIMO Availability
Available in macro eNodeBs as of LTE TDD eRAN8.1.
Not available in micro eNodeBs.
Not available in LampSite eNodeBs.
Summary This feature allows a maximum of two UEs to share the same time-frequency resource.
Benefits This feature increases cell throughput in the uplink.
Description When an eNodeB is equipped with eight receive antennas, it can use uplink 2x8 MU-MIMO. The eNodeB can adaptively switch between uplink 2x8 MU-MIMO and uplink 8-antenna receive diversity. If the uplink CQI of a UE is high or the orthogonality between the uplink channels of this UE and other UEs is high, the eNodeB uses uplink 2x8 MU-MIMO to improve uplink performance; otherwise, the eNodeB uses 8-antenna receive diversity. This feature can be used only with the PUSCH. This feature allows the eNodeB to select UEs that can achieve the highest throughput for pairing.
Enhancement The following functions are introduced in LTE TDD eRAN11.0:
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MCS index decrease and RB number increase for UEs with a small amount of data, increasing the UE pairing probability
MU-MIMO for VoLTE UEs, increasing the UE pairing probability and the VoLTE UE capacity
Dependency The eNodeB must provide eight receive antennas in each cell. This feature requires the following features:
TDLOFD-001015 Enhanced Scheduling
TDLOFD-001062 UL 8-Antenna Receive Diversity
TDLOFD-001094 Control Channel IRC
When the LBBPc is used, this feature is not compatible with the following features:
TDLOFD-001075 SFN
TDLOFD-002008 Adaptive SFN/SDMA
TDLOFD-001098 Inter-BBP SFN
TDLOFD-001080 Inter-BBU SFN
TDLOFD-001081 Inter-BBP Adaptive SFN/SDMA
TDLOFD-001082 Inter-BBU Adaptive SFN/SDMA
3.2 Interference Handling 3.2.1 TDLOFD-001012 UL Interference Rejection Combining Availability This feature was introduced in LTE TDD eRAN1.0.
Summary In addition to DL and UL inter-cell interference coordination (ICIC), Huawei LTE TDD eRAN1.0 provides interference rejection combining (IRC) to effectively mitigate inter-cell interference.
Benefits This feature improves system performance in the presence of interference. Therefore, enhanced network coverage and better service quality are provided for CEUs.
Description IRC is a receive-antenna combining technique to effectively mitigate inter-cell interference. IRC is often used together with receive diversity. In theory, IRC can be used for MIMO decoding, and it is particularly effective for colored interference.
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The main advantage of IRC is that it can outperform maximum ratio combining (MRC) in terms of signal demodulation in the presence of interference or congestion.
Enhancement In eRAN7.0, SmartIRC is additionally available in 8R scenarios. This enhancement takes effect for 8R RRU and 4R COMP scenarios. Compared with the original IRC feature that enables eNodeBs to check for interference, this enhancement enables the eNodeBs to additionally identify the number of equivalent interference sources. This increases the precision of interference estimations and improves the interference rejection performance.
Dependency eNodeBs must be configured with two or more receive antennas. In 4R COMP scenario, SmartIRC needs the hardware type of serving cell and collaborative cell to be same.
3.2.2 TDLOFD-060201 Adaptive Inter-Cell Interference Coordination Availability This feature is:
Available in macro eNodeBs as of LTE TDD eRAN6.0.
Not available in micro eNodeBs.
Not available in LampSite eNodeBs.
Summary Adaptive ICIC determines whether to enable ICIC in an area based on inter-cell interference and cell load, and automatically configures edge band modes and optimizes ICIC working modes and edge band modes based on load changes. With adaptive ICIC, eNodeBs independently report cell information to the ECO6910, and then the ECO6910 uses the reported information to configure and optimize ICIC working modes and edge band modes. This feature implements frequency reuse and effective inter-cell interference control. Huawei ECO6910, whose network element (NE) type is eCoordinator, serves as a coordinator on a radio network and provides a platform for implementing adaptive ICIC.
Benefits This feature offers the following benefits:
Reduces inter-cell interference and improves CEU throughput in intra-frequency networking mode.
Simplifies ICIC configuration for operators to reduce operation and maintenance (O&M) costs.
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Description Users can create ICIC optimization tasks on the eCoordinator to perform LTE TDD adaptive ICIC optimization. This feature provides the following functions:
Manages ICIC optimization tasks. Users can add, delete, modify, or query ICIC optimization tasks. When adding an optimization task, users need to select an optimization range for cells and set optimization parameters and policies. Then, users can modify parameters, policies, and the optimization range for the optimization task. Users can start an ICIC optimization task based on the preset optimization range, parameters, and policies. After users stop an ICIC optimization task, ICIC optimization for the cells within the optimization range is also stopped. Only one optimization task can be started for each cell. The optimization ranges for different tasks cannot overlap. The eCoordinator can automatically perform slow self-optimization and reconfigure the edge band mode based on the load data that is periodically collected. After adaptive ICIC is enabled, the edge band mode is automatically configured. Users cannot manually configure the mode.
Manages ICIC optimization suggestions. Once an optimization task has been performed, the eCoordinator provides optimization suggestions consisting of edge band mode assignments that comply with the optimization range. Users can choose automatic or manual delivery of optimization suggestions. In automatic delivery mode, the eCoordinator automatically delivers the optimization suggestions to eNodeBs. In manual delivery mode, the eCoordinator delivers the optimization suggestions to eNodeBs only after users has confirmed them.
Enhancement None
Dependency The ECO6910 must be deployed. This feature does not apply to micro eNodeBs. This feature cannot be used with TDLBFD-002022 Static ICIC.
3.2.3 TDLOFD-001094 Control Channel IRC Availability This feature was introduced in LTE TDD eRAN6.0.
Summary This feature prevents the PUCCH from being affected by inter-cell interference.
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Benefits This feature enhances interference resistance for uplink control channels and improves control channel coverage.
Description IRC combines signals on the PUCCH received by multiple antennas. Compared with MRC, IRC performs better on colored interference mitigation. eNodeBs support adaptive switching between IRC and MRC for PUCCHs. When there is colored interference, eNodeBs select IRC. In other cases, eNodeBs select MRC.
Enhancement None
Dependency This feature requires one of the following features:
TDLBFD-00202001 UL 2-Antenna Receive Diversity
TDLOFD-001005 UL 4-Antenna Receive Diversity
TDLOFD-001062 UL 8-Antenna Receive Diversity
eNodeBs must be configured with two or more receive antennas and the LBBPc is not used.
3.2.4 TDLOFD-001075 SFN Availability This feature is:
Available in macro eNodeBs as of LTE TDD eRAN3.0.
Not applicable to Micro.
Available in LampSite eNodeBs as of LTE TDD eRAN6.0.
Summary This feature combines multiple common cells in one single frequency network (SFN) cell. It can also reduce the number of handovers between cells.
Benefits This feature provides the following benefits:
This feature reduces interference at the cell edge in a densely populated area.
The number of handovers decreases.
Description An SFN cell is a combination of multiple common cells, which use the same cell ID and apply joint time-frequency resource scheduling. SFN converts inter-cell interference into the
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time-frequency resources scheduled inside the SFN cell, and increases the proportion of UEs with a high SINR in the entire RAN. In this feature, an eNodeB allows multiple RRUs to serve an SFN cell. In the downlink, joint scheduling is used and all RRUs transmit the same signals except the physical downlink shared channels (PDSCHs) of beamforming users and UE-specific reference signals. In the uplink, joint scheduling is used at the physical and Media Access Control (MAC) layers. According to the measurement reports of a UE at the physical layer, the MAC layer selects the serving RRU with the best channel quality for the UE. The physical layer processes all UE signals and reports only the serving RRU physical uplink shared channel (PUSCH) and physical uplink control channel (PUCCH) of the UE to the MAC layer.
Enhancement In eRAN3.1, eNodeBs supported multi-user beamforming and UL CoMP in SFN cells, and allowed a maximum of seven cells to be combined into an SFN cell. In eRAN6.0, eNodeBs can work in 2T2R mode only in the LampSite solution. In LTE TDD eRAN7.0, this enhancement enables eNodeBs to selectively receive physical uplink shared channel (PUSCH) data at the Media Access Control (MAC) layer. When multiple working RRUs receive PUSCH data from a UE, they demodulate and then transmit the received PUSCH data to the MAC layer. At the MAC layer, the eNodeB combines the optimal PUSCH data, increasing uplink coverage. In LTE TDD eRAN8.1, eNodeBs support outdoor 8T8R SFN mode, and outdoor 4T4R and 8T8R hybrid SFN mode.
Dependency This feature cannot be used with the following features:
TDLBFD-002022 Static Inter-Cell Interference Coordination
SEFD-033100 Adaptive Inter-Cell Interference Coordination – LTE
TDLOFD-001031 Extended CP
TDLOFD-001039 RF Channel Intelligent Shutdown
TDLAOFD-003002 Intra-eNodeB DL CoMP in Adaptive Mode
This feature does not work when the eNodeB bandwidth is 5 MHz or 15 MHz. When the LBBPc is configured, this feature cannot be used with TDLOFD-001058 UL 2x4 MU-MIMO or TDLOFD-081205 UL 2*8 MU-MIMO.
For Macro eNodeB:
A macro eNodeB must be configured with a minimum of four antennas for transmission and reception.
For LampSite eNodeB:
Selective reception of data at the MAC layer is not supported in eRAN7.0.
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3.2.5 TDLOFD-002008 Adaptive SFN/SDMA Availability This feature is:
Available in macro eNodeBs as of LTE TDD eRAN3.1.
Not available in micro eNodeBs.
Available in LampSite eNodeBs as of LTE TDD eRAN6.0.
Summary After multiple common cells are combined into one SFN cell, the eNodeB categorizes UEs based on signal quality and adaptively performs joint scheduling or independent scheduling at time-frequency resources of multiple cells. Space Division Multiple Access (SDMA) is applied in the process of independently scheduling time-frequency resources of multiple cells.
Benefits Adaptive SFN/SDMA increases the resource usage and the system throughput when guaranteeing the cell coverage quality.
Description Based on the uplink reference signal receive power (RSRP), the eNodeB judges the UE attribute and then performs one of the following operations:
Jointly scheduling the resources of all cells
Jointly scheduling the resources of part of cells
Independently scheduling the resources of a single cell
In addition, the eNodeB determines a list of working RRUs. The PDSCHs and PUSCHs of all cells served by the involved RRUs will be jointly or independently scheduled.
Enhancement In eRAN7.0, this feature enables eNodeBs to selectively receive PUSCH data at the MAC layer upon uplink transmission. When multiple working RRUs receive PUSCH data from a UE, they demodulate and then transmit the received PUSCH data to the MAC layer. At the MAC layer, the eNodeB combines the correctly demodulated PUSCH data, increasing uplink coverage. In LTE TDD eRAN8.1, eNodeBs support the outdoor 8T8R SFN mode, outdoor 4T4R and 8T8R hybrid SFN mode. In LTE TDD eRAN11.0, 8T8R or 4T4R SFN cells support inter-RRU coordinated beamforming.
Dependency This feature depends on TDLOFD-001075 SFN.
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3.2.6 TDLOFD-001098 Inter-BBP SFN Availability This feature is:
Available in macro eNodeBs as of LTE TDD eRAN3.1.
Not available in micro eNodeBs.
Available in LampSite eNodeBs as of LTE TDD eRAN6.0.
Summary RRUs serving the same SFN cell can be connected to different BBPs in the same BBU subrack so that the time-frequency resources of multiple physical cells can be jointly scheduled.
Benefits This feature extends the application range of SFN.
Description RRUs serving multiple cells can interact with each other by connecting to different BBPs, which extends the application range of SFN. In LTE TDD eRAN3.1, multiple RRUs can be connected to different BBPs in the same BBU subrack on the macro network. They serve the same SFN cell and implement joint transmission and reception in the SFN cell.
Enhancement In LTE TDD eRAN6.0, only the LampSite solution uses 2T2R. In the LampSite solution, multiple pRRUs can be connected to different LBBPs in the same BBU subrack. They serve the same SFN cell and implement joint transmission and reception in the SFN cell. In eRAN7.0, this feature enables eNodeBs to selectively receive PUSCH data at the MAC layer upon uplink transmission. When multiple working RRUs receive PUSCH data from a UE, they demodulate and then transmit the received PUSCH data to the MAC layer. At the MAC layer, the eNodeB combines the correctly demodulated PUSCH data, increasing uplink coverage. In eRAN8.1, the eNodeB supports the outdoor 8T8R SFN mode and the outdoor 4T4R and 8T8R hybrid SFN mode.
Dependency This feature depends on TDLOFD-001075 SFN. This feature does not work with the following features:
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If the LBBPc is used, this feature does not work with TDLOFD-001058 UL 2x4 MU-MIMO or TDLOFD-081205 UL 2x8 MU-MIMO. The eNodeB does not support SFN using 8T8R. In the LampSite solution, this feature depends on the following features:
TDLOFD-001132 Intra-BBU Baseband Sharing (2T)
TDLOFD-001076 CPRI Compression
3.2.7 TDLOFD-001080 Inter-BBU SFN Availability This feature is:
Available in macro eNodeBs as of LTE TDD eRAN3.1.
Not available in micro eNodeBs.
Not available in LampSite eNodeBs.
Summary RRUs serving the same SFN cell can be connected to different BBUs so that the time-frequency resources of multiple physical cells can be jointly scheduled.
Benefits This feature extends the application range of SFN. If one RRU of the SFN cell is replaced, the physical connections of the RRU do not need to be adjusted.
Description RRUs serving multiple cells communicate with each other through BBU interconnection, which extends the application range of SFN. In eRAN3.1, the troubleshooting mechanism will aggravate the impact of a fault. For example, if the primary LBBP is faulty, or if a communication link on the primary or secondary BBU is faulty, the RRU is disconnected from the BBU.
Enhancement In LTE TDD eRAN6.0, this feature can be enabled if one RRU of the SFN cell is running properly, regardless of whether the RRU is connected to the primary BBU or the secondary BBU. In LTE TDD eRAN6.0, the troubleshooting mechanism is optimized. RRUs connected to the secondary BBU can be bound to a standby cell in an inter-BBU SFN cell. If the secondary BBU is faulty, the bound standby cell is automatically activated. The RRUs connected to the secondary BBU can continue transmitting data. If RRUs are not bound to a standby cell, the troubleshooting mechanism is the same as that of LTE TDD eRAN3.1. In eRAN7.0, this feature enables eNodeBs to selectively receive PUSCH data at the MAC layer upon uplink transmission. When multiple working RRUs receive PUSCH data from a UE, they demodulate and then transmit the received PUSCH data to the MAC layer. At the MAC layer, the eNodeB combines the correctly demodulated PUSCH data, increasing uplink coverage.
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In LTE TDD eRAN8.1, the eNodeB supports the outdoor 8T8R SFN mode and the outdoor 4T4R and 8T8R hybrid SFN mode.
Dependency This feature depends on the following features and inherits the corresponding mutual exclusive relationships:
TDLOFD-001075 SFN
TDLOFD-001098 Inter-BBP SFN
If the LBBPc is used, this feature does not work with TDLOFD-001058 UL 2x4 MU-MIMO or TDLOFD-081205 UL 2x8 MU-MIMO. The USU3900 or USU3910 is required for BBU interconnection.
3.2.8 TDLOFD-001081 Inter-BBP Adaptive SFN/SDMA Availability This feature is:
Available in macro eNodeBs as of LTE TDD eRAN3.1.
Not available in micro eNodeBs.
Available in LampSite eNodeBs as of LTE TDD eRAN6.0.
Summary RRUs serving the same SFN cell can be connected to BBPs in the same BBU subrack so that the time-frequency resources of multiple physical cells can be jointly or independently scheduled.
Benefits This feature extends the application range of adaptive SFN/SDMA.
Description Inter-BBP connection implements data interaction between multiple cells, and extends the application range of adaptive SFN/SDMA. On the macro network, multiple RRUs are connected to different BBPs in the same BBU subrack and serve the same SFN cell. In an SFN cell, the eNodeB adaptively selects joint transmission or reception and SDMA.
Enhancement In the LampSite solution, multiple pRRUs are connected to different BBPs in the same BBU subrack and serve the same SFN cell. In an SFN cell, the eNodeB adaptively selects joint transmission or reception and SDMA. In eRAN7.0, this feature enables eNodeBs to selectively receive PUSCH data at the MAC layer upon uplink transmission. When multiple working RRUs receive PUSCH data from a UE, they demodulate and then transmit the received PUSCH data to the MAC layer. At the
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MAC layer, the eNodeB combines the correctly demodulated PUSCH data, increasing uplink coverage. In LTE TDD eRAN8.1, eNodeBs support the outdoor 8T8R SFN mode, outdoor 4T4R and 8T8R hybrid SFN mode. In LTE TDD eRAN11.0, 8T8R or 4T4R SFN cells support inter-RRU coordinated beamforming.
Dependency This feature depends on the following features and inherits the corresponding mutual exclusive relationships:
TDLOFD-001075 SFN
TDLOFD-002008 Adaptive SFN/SDMA
TDLOFD-001098 Inter-BBP SFN
If the LBBPc is used, this feature does not work with TDLOFD-001058 UL 2x4 MU-MIMO or TDLOFD-081205 UL 2x8 MU-MIMO. In the LampSite solution, this feature depends on TDLOFD-001076 CPRI Compression.
3.2.9 TDLOFD-001082 Inter-BBU Adaptive SFN/SDMA Availability This feature is:
Available in macro eNodeBs as of LTE TDD eRAN3.1.
Not available in micro eNodeBs.
Not available in LampSite eNodeBs.
Summary RRUs serving the same SFN cell are connected to different BBUs so that the time-frequency resources of multiple physical cells can be jointly scheduled.
Benefits This feature extends the application range of SFN/SDMA. If one RRU of the SFN cell is replaced, the physical connections of the RRU do not need to be adjusted.
Description RRUs serving multiple cells communicate with each other through BBU interconnection, which extends the application range of SFN and SDMA. In LTE TDD eRAN3.1, this feature can be enabled only when at least one of the RRUs connected to the primary BBU is functioning properly. An RRU is functioning properly when the following conditions are met:
The RRU is not blocked.
The LBBP connected to the RRU is functioning properly.
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In eRAN7.0, this feature enables eNodeBs to selectively receive PUSCH data at the MAC layer upon uplink transmission. When multiple working RRUs receive PUSCH data from a UE, they demodulate and then transmit the received PUSCH data to the MAC layer. At the MAC layer, the eNodeB combines the correctly demodulated PUSCH data, increasing uplink coverage.
Enhancement In LTE TDD eRAN6.0, this feature can be enabled if one RRU of the SFN cell is running properly, regardless of whether the RRU is connected to the primary BBU or the secondary BBU. In LTE TDD eRAN8.1, eNodeBs support the outdoor 8T8R SFN mode, outdoor 4T4R and 8T8R hybrid SFN mode. In LTE TDD eRAN11.0, 8T8R or 4T4R SFN cells support inter-RRU coordinated beamforming.
Dependency This feature depends on the following feature:
TDLOFD-001075 SFN
TDLOFD-002008 Adaptive SFN/SDMA
TDLOFD-001098 Inter-BBP SFN
TDLOFD-001080 Inter-BBU SFN
TDLOFD-001081 Inter-BBP SFN/SDMA
If the LBBPc is used, this feature does not work with TDLOFD-001058 UL 2x4 MU-MIMO or TDLOFD-081205 UL 2x8 MU-MIMO. The USU3900 or USU3910 is required for BBU interconnection.
3.2.10 TDLOFD-070227 PDCCH DCS in SFN Availability This feature is:
Available in macro eNodeBs and LampSite eNodeBs as of LTE TDD eRAN7.0.
Not available in micro eNodeBs.
Summary In SFN scenarios, this feature enables the eNodeB to allocate power only to the working RRU, protecting the PDCCHs in neighboring cells against the impact of non-working RRUs.
Benefits This feature increases the PDCCH capacity and coverage in SFN scenarios.
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Description This feature is implemented as follows: 1. Based on the strength of uplink signals received by each RRU, the eNodeB estimates the downlink signal strength of each RRU, which refers to the equivalent strength of signals sent from each RRU to a UE. 2. The eNodeB selects the RRUs, of which the estimated signal strength is large, as working RRUs for the UE, and adds them to the working RRU list. 3. The eNodeB allocates both power and CCE resources to working RRUs and allocates only CCE resources to non-working RRUs. This allocation mechanism reduces interference to the PDCCHs in neighboring cells and does not affect signals received by the UE.
Enhancement None
Dependency This feature requires TDLOFD-002008Adaptive SFN/SDMA. This feature cannot be used with the feature TDLOFD-081221 PDCCH SDMA in SFN.
3.2.11 TDLOFD-081221 PDCCH SDMA in SFN Availability This feature is:
Available in macro eNodeBs and LampSite eNodeBs as of LTE TDD eRAN8.1.
Not available in micro eNodeBs.
Summary This feature is introduced to solve the PDCCH capacity problem of SFN cells. By implementing the SDMA between RRUs of PDCCH in an SFN cell, this feature increases the number of UEs that can be scheduled in each transmission time interval (TTI) in the PDCCH load congestion scenario. It is recommended that this feature be enabled when the PDCCH load of an SFN cell is heavy.
Benefits This feature increases the PDCCH capacity in SFN scenarios.
Description Based on the uplink RSSI of each RRU, the eNodeB estimates the downlink RSSI of each RRU, which refers to the equivalent strength indicator of signals sent from each RRU to a UE. Then, the eNodeB selects the RRU with a greater estimated RSSI as a working RRU for the UE PDCCH. The PDCCH allocated to the UE occupies only the control channel element (CCE) resources of RRUs in the RRU working set of the UE. CCE resources corresponding to other RRUs can be allocated to other UEs. This mechanism increases the CCE resource usage of PDCCHs in an SFN cell and the PDCCH capacity.
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Enhancement None
Dependency This feature depends on TDLOFD-002008 Adaptive SFN/SDMA. This feature depends on TDLOFD-070227 PDCCH DCS in SFN.
3.2.12 TDLOFD-070223 Multi-Cell Interference Randomizing and Coordination Availability This feature was introduced in LTE TDD eRAN7.0.
Summary When the network is lightly loaded, this feature enables the eCoordinator to allocate different frequency-domain resources to UEs in different cells and to optimize the UE power configurations. In this way, co-channel interference between cells is reduced.
Benefits This feature offers the following benefits:
Increases the spectral efficiency, proportion of high-order MCSs, handover success rate, and service rate experienced by users.
Decreases the service drop rate.
Description This feature is implemented on the eCoordinator. The eCoordinator obtains information about cells (including intra- and inter-eNodeB cells) to determine the start position of the RBGs that are allocated to the UEs in each cell. Therefore, the UEs in different cells are allocated different resources and therefore inter-cell interference are reduced. In addition, the eCoordinator optimizes the UE power configurations to further reduce inter-cell interference. In this way, the signal quality is improved.
Enhancement None
Dependency This feature requires the eCoordinator.
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3.2.13 TDLOFD-080203 Coordinated Scheduling based Power Control Availability This feature is
applicable to Macro from LTE TDD eRAN8.0
not applicable to Micro
not applicable to LampSite
Summary Based on coordinated scheduling, Coordinated Scheduling based Power Control (CSPC) dynamically configures downlink transmit power for each subframe in each cell within an area for inter-cell interference coordination.
Benefits In an E-UTRAN, physical resource block (PRB) usage increases with the traffic volume. UEs experience severe interference in densely populated urban areas where intra-frequency eNodeBs are deployed with an inter-site distance of less than 500 m. CSPC efficiently coordinates inter-cell interference and offers the following benefits:
Increases hotspot cell capacity in a load-unbalanced network.
Increases the throughput of cell edge UEs across the network.
Reduces handover failures and service drops caused by DL interference.
Description CSPC coordinates TTI-specific transmit power configurations in individual cells. It reduces inter-cell interference based on collaboration of scheduling with power control. During CSPC, the centralized controller periodically collects UE scheduling information about each E-UTRAN cell, calculates the optimal cell power configurations for the entire network, and delivers the results to the E-UTRAN NodeBs (eNodeBs). The eNodeBs then change their DL power to the received power configurations. Each cell obtains the transmit power configurations for the local cell and its neighboring cells on the same time-frequency resources and promptly updates the modulation and coding schemes (MCSs) for cell edge UEs. In addition, if a UE experiences interference from neighboring cells, the serving cell schedules the UE on the time-frequency resources where the neighboring cells reduce transmit power. This type of scheduling increases spectral efficiency of the UE. Figure 3-1 shows an example of time-domain power coordination. In this example, cell 1 and cell 2 are neighboring cells. To meet their respective scheduling requirements, the cells coordinate the transmit power for resource elements (REs) that carry data on the physical downlink shared channel (PDSCH) within each TTI. In the figure, a blue rectangle denotes an RE with full transmit power, a yellow rectangle denotes an RE with increased transmit power, and a gray rectangle denotes an RE with decreased transmit power.
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Figure 3-1 Example of time-domain power coordination
Enhancement None
Dependency
eNodeB This feature is dependent on the Cloud BB architecture.
3.2.14 TDLOFD-081217 Interference Detection and Suppression Availability Co-channel and adjacent-channel interference detection and identification is:
Available in macro eNodeBs as of LTE TDD eRAN8.1.
Not available in LampSite eNodeBs.
Available in micro eNodeBs as of LTE TDD eRAN8.1.
Atmospheric duct remote interference suppression is:
Available in macro eNodeBs as of LTE TDD eRAN11.1.
Not available in LampSite eNodeBs.
Not available in micro eNodeBs.
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Summary An eNodeB detects whether its cells are subject to interference. If they are subject to interference, the eNodeB uses the channel interference detection algorithm to identify co-channel and adjacent-channel interference, and reports the result to the U2000. The result can be used as reference for network planning and optimization for operators. When atmospheric duct remote interference occurs, the eNodeB uses the enhanced uplink demodulation algorithm, enhanced uplink power control policy, and more conservative scheduling policy to ensure stable scheduling for access signaling and minimize the impact of interference on system performance.
Benefits The eNodeB automatically detects co-channel and adjacent-channel interference and identifies interference caused by LTE TDD system out-of-synchronization, improving interference detection efficiency. When atmospheric duct remote interference occurs, the eNodeB uses the stable scheduling policy and enhanced uplink demodulation algorithm to minimize the impact of interference on system performance, improving network KPIs.
Description The eNodeB detects the received signal power on the UpPTS and on each resource block (RB) in common uplink subframes in the current cell to determine whether the cell is subject to interference. If it is subject to interference, the eNodeB analyzes the spectrum roll-off characteristics to identify co-channel and adjacent-channel interference, and reports the result to the U2000. The result can be used as reference for network planning and optimization for operators. When the eNodeB detects that the interference to uplink subframes exceeds a specified threshold, atmospheric duct remote interference suppression enables the eNodeB to:
Correct the channel estimation result to improve uplink demodulation performance.
Automatically increase the uplink transmit power for UEs that initially access the network to enhance the anti-interference capability of access signaling.
Use the conservative scheduling policy for access signaling sent after MSG3 to ensure stable scheduling of access signaling.
Enhancement In LTE TDD eRAN11.1, the atmospheric duct remote interference suppression function has been added.
Dependency None
3.2.15 TDLOFD-081219 Interference Based Uplink Power Control Availability This feature is:
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Available in macro eNodeBs as of LTE TDD eRAN8.1.
Available in LampSite eNodeBs as of LTE TDD eRAN8.1.
Available in micro eNodeBs as of LTE TDD eRAN8.1.
Summary Cells exchange interference information with each other. The eNodeB controls the uplink transmit power of UEs in the local cell that generates strong interference on neighboring cells based on the obtained inter-cell interference.
Benefits The feature helps increase the data rate and access success rate of cell edge UEs.
Description When this feature is disabled, the eNodeB performs uplink power control based on the available uplink resources and UE number in the local cell without considering interference from UEs in the local cell on its neighboring cells. As a result, the interference from the local cell to neighboring cells may be strong, and the data rate of cell edge UEs is low. When this feature is enabled, the eNodeB performs uplink power control with the consideration of interference from the local cell on its neighboring cells. If the interference from the local cell on its neighboring cells is strong, the eNodeB lowers the transmit power of UEs in the local cell that generates strong interference on neighboring cells, thereby increasing the data rate and access success rate of cell edge UEs in neighboring cells. If the interference from the local cell on its neighboring cells is weak, the eNodeB performs uplink power control on UEs in the local cell based on the available uplink resources and UE number in the local cell.
Enhancement None
Prerequisite and Mutually Exclusive Features
X2 interfaces must be configured between eNodeBs.
The InnerLoopPuschSwitch option must be selected.
3.2.16 TDLOFD-081232 Enhanced Uplink Power Control Availability This feature is:
Available in macro eNodeBs as of LTE TDD eRAN8.1.
Available in LampSite eNodeBs as of LTE TDD eRAN8.1.
Not available in micro eNodeBs.
Summary This feature provides the following functions:
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Enabling fast PUCCH power control The PUCCH power convergence can be accelerated based on the PUCCH group power control and the accelerated PUCCH power control command generation.
Setting the type of UEs to which optimized closed-loop PUSCH power control in dynamic scheduling mode applies This function decreases interference on neighboring cells caused by the enabling of optimized closed-loop PUSCH power control in dynamic scheduling mode.
Benefits This feature increases downlink cell throughput by accelerating PUCCH power control convergence, decreases interference on neighboring cells caused by the enabling of optimized closed-loop PUSCH power control in dynamic scheduling mode, and increases uplink throughput as well as the access success rate when optimized closed-loop PUSCH power control in dynamic scheduling mode is enabled.
Description With this feature enabled, the eNodeB generates multiple PUCCH power control commands after receiving one feedback over the PUCCH from a UE, and then sends the PUCCH power control commands to the UE based on PUCCH group power control. In this way, fast PUCCH power control convergence is achieved. With this feature enabled, configuring the type of UEs to which optimized closed-loop PUSCH power control in dynamic scheduling mode applies can decrease interference on neighboring cells caused by the enabling of optimized closed-loop PUSCH power control in dynamic scheduling mode.
Enhancement N/A
Dependency This feature depends on the following features:
TDLBFD-081104 PUCCH Outer Loop Power Control
TDLBFD-002026 Uplink Power Control
3.2.17 TDLOFD-110205 Scheduling
Intra-eNodeB Uplink Coordinated
Availability This feature is:
Available in macro eNodeBs as of LTE TDD eRAN11.0.
Not available in micro eNodeBs.
Not available in LampSite eNodeBs.
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Summary Intra-eNodeB uplink coordinated scheduling measures and estimates the actual interference arising during data transmissions based on scheduling information exchange between intra-eNodeB cells, thereby improving the accuracy of modulation and coding scheme (MCS) selection.
Benefits This feature improves the accuracy of MCS selection and therefore increases the uplink throughput of UEs at the cell edge and certain UEs in the cell center.
Description Intra-eNodeB uplink coordinated scheduling is an enhancement of basic AMC. Based on scheduling information exchange between the serving cell and coordinating cells, this feature can identify in advance UEs with interference during data transmissions and measure and estimate channel quality again for data transmissions. This feature uses multi-cell coordinated measurement based on scheduling information exchange to accurately predict the interference source during UE data transmissions. In the case of time-varying interference, this feature can better trace interference changes and improve the accuracy of SINR prediction and MCS selection, thereby increasing the system throughput.
Enhancement None
Dependency This feature depends on the following features:
TDLBFD-001006 AMC
TDLBFD-002025 Basic Scheduling
3.2.18 TDLOFD-110206 Inter-eNodeB Uplink Coordinated Scheduling Availability This feature is:
Available in macro eNodeBs as of LTE TDD eRAN11.0.
Not available in micro eNodeBs.
Not available in LampSite eNodeBs.
Summary In the case of multi-BBU interconnection, inter-eNodeB uplink coordinated scheduling measures and estimates the actual interference arising during data transmissions based on scheduling information exchange between inter-eNodeB cells, thereby improving the accuracy of MCS selection.
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Benefits This feature improves the accuracy of MCS selection and therefore increases the uplink throughput of UEs at the cell edge and certain UEs in the cell center. Compared with inter-eNodeB uplink coordinated scheduling, inter-eNodeB uplink coordinated scheduling allows for coordinating cells served by different BBUs and adjusts the coordination scope, further improving the uplink throughput.
Description Inter-eNodeB uplink coordinated scheduling can coordinate adaptive modulation and coding for cells served by different BBUs. When the serving cell and coordinating cells are configured on different BBUs, USUs must be used for interconnecting BBUs to implement scheduling information exchange between these cells. Except for this difference, inter-eNodeB uplink coordinated scheduling has the same functions as inter-eNodeB uplink coordinated scheduling. When both inter-eNodeB uplink coordinated scheduling and inter-eNodeB uplink coordinated scheduling are enabled, uplink coordinated scheduling can be implemented in the same BBU or between BBUs.
Enhancement None
Dependency This feature depends on the following features:
TDLBFD-001006 AMC
TDLBFD-002025 Basic Scheduling
TDLOFD-110205 Intra-eNodeB Uplink Coordinated Scheduling
3.2.19 TDLOFD-111208 Uplink Interference Coordination Availability This feature is:
Available in macro eNodeBs as of LTE TDD eRAN11.1.
Not available in LampSite eNodeBs.
Not available in micro eNodeBs.
Summary This feature enables an eNodeB to jointly schedule radio resources in multiple cells to coordinate uplink interference. It reduces uplink coverage shrinkage caused by increased noise and interference in medium- and heavy-load scenarios.
Benefits This feature improves uplink coverage of cells in medium- and heavy-load scenarios.
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Description This feature applies to one or more intra-frequency cell clusters. Cells in each cluster report interference information and UE scheduling information to the centralized controller, and the centralized scheduler allocates appropriate time-frequency resources to UEs based on the signal quality requirements of UEs to mitigate interference. In this way, uplink coverage of cells improves in medium- and heavy-load scenarios.
Enhancement None
Dependency
eNodeB This feature is implemented in Cloud BB (USU3900 and USU3910) or IP RAN scenarios.
UE None
Transport network In IP RAN scenarios, the transmission bandwidth of a cell must be 5 Mbit/s or higher, and the unidirectional transmission delay must be less than 2 ms.
Core network None
OSS None
Other features This feature does not work with the following features: TDLOFD-001031 Extended CP TDLOFD-001007 High Speed Mobility
Others None
3.2.20 TDLOFD-111201 Remote Interference Adaptive Avoidance Availability This feature is:
Available in macro eNodeBs as of LTE TDD eRAN11.1.
Not available in micro eNodeBs.
Not available in LampSite eNodeBs.
Summary When an eNodeB detects remote interference caused by an atmospheric duct, it sends and detects characteristic sequences to achieve automatic interference avoidance and reduce interference to remote eNodeBs. After remote interference disappears, the eNodeB
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automatically recovers the normal sending mode to reduce the negative impact of interference avoidance on system performance.
Benefits When remote interference is generated due to an atmospheric duct, the eNodeB automatically rolls back the special subframe configuration from 9:3:2/10:2:2 to 3:9:2 over the air interface to extend the guard period (GP) and reduce interference to remote eNodeBs. The eNodeB sends and detects characteristic sequences to determine that interference is generated within the system, helping identify remote interference caused by an atmospheric duct. Characteristic sequences are used to detect the eNodeB ID of an interference source cell, helping determine the interference source.
Description Due to atmospheric duct reciprocity, downlink signals of an eNodeB subject to remote interference caused by an atmospheric duct interfere with the uplink transmission of a remote eNodeB. When the eNodeB detects remote interference, it periodically sends characteristic sequences in the DwPTS and checks characteristic sequences in the UpPTS and uplink subframes. When characteristic sequences are detected during several consecutive periods, the eNodeB automatically rolls back the special subframe configuration to 3:9:2 over the air interface and stops transmissions in the DwPTS to reduce interference to the remote eNodeB and further determines the eNodeB ID of the interference source cell based on the characteristic sequences. If no characteristic sequence is detected during several consecutive periods, the eNodeB automatically restores the special subframe configuration to 9:3:2/10:2:2 to reduce the negative impact of interference avoidance on system performance.
Enhancement None
Dependency
eNodeB This feature does not apply to LampSite or micro eNodeBs.
UE None
Transport network None
Core network None
OSS None
Other features This feature requires the following features: −
TDLOFD-00102604 uplink-downlink special subframe configuration type 6
−
TDLBFD-00100702 uplink-downlink special subframe configuration type 7
This feature does not work with any of the following features: Issue 02 (2016-07-30)
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−
TDLOFD-001031 Extended CP
−
TDLOFD-002008 Adaptive SFN/SDMA
−
TDLOFD-001098 Inter-BBP SFN
−
TDLOFD-001080 Inter-BBU SFN
−
TDLOFD-001081 Inter-BBP Adaptive SFN/SDMA
−
TDLOFD-001082 Inter-BBU Adaptive SFN/SDMA
Others None
3.2.21 TDLOFD-001066 Intra-eNodeB UL CoMP Availability This feature is:
Available in macro eNodeBs as of LTE TDD eRAN3.0.
Not available in LampSite eNodeBs.
Not available in micro eNodeBs.
Summary Uplink Coordinated Multipoint Reception (UL CoMP) implements signal combining and interference mitigation in multiple cells. Phase I of this feature is applicable only in intra-BBU intra-BBP cells. Phase II of this feature is applicable also in intra-BBU inter-BBP cells.
Benefits This feature increases the uplink throughput of not only cell edge users (CEUs) but also some cell center users (CCUs) in intra-BBU intra- or inter-BBP cells. In addition, this feature improves the performance of UL CoMP UEs.
Description This feature can be used in two scenarios. In scenario 1, signal combining gains are expected. To provide such gains, this feature uses the antennas of multiple cells (each with multiple receive antennas) to receive PUSCH signals from a UE. This UE, also called a type-1 UE, is at the edge of the serving cell and close to the coordinating cell. In scenarios 2, interference mitigation gains are expected. To provide such gains, this feature utilizes a type-1 UE's signals to reduce its interference with a UE in the coordinating cell. This UE, also called a type-2 UE, shares some physical resource blocks (PRBs) with the type-1 UE.
Enhancement
In LTE TDD eRAN6.0, this feature can be used in 4R cells, that is, cells with four receive antennas.
In LTE TDD eRAN7.0, this feature can be used in 4R cells and based on smart IRC.
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In LTE TDD eRAN8.1, this feature can be used in 8R cells.
In LTE TDD eRAN11.0: −
This feature can be used in SFN cells, macro cells.
−
This feature can preferentially select VoIP users for UL CoMP.
−
This feature can be deployed on the LBBPd that supports six cells or the UBBPd with one chip supporting six cells.
−
The eNodeB can automatically adjust the reporting interval of UL CoMP A3 measurement reports and disable UL CoMP when the main control board's CPU is flow controlled. The two functions reduce resource consumption for UL CoMP when the network is heavily loaded.
−
This feature can be used in three cells when this feature's switch and the 3-cell UL CoMP switch are both turned on. When this feature uses the antennas of three cells to receive signals from a UE, it provides higher gains than the function that uses the antennas of one or two cells to receive signals from a UE. Figure 3-2 compares 2-cell UL CoMP (left) and 3-cell UE CoMP (right). Figure 3-2 2-cell UL CoMP (left) and 3-cell UE CoMP (right)
Dependency
eNodeB This feature requires that cells have two, four, or eight receive antennas. To support 4R or 8R cells, the BBP model must be LBBPd, UBBPd, or UBBPe. This feature requires that the system bandwidth be not 5 MHz. This feature requires that the distance between the RRU and BBU be less than 20 km.
eCoordinator None
UE None
Transport network None
Core network None
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OSS
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None
Other features −
This feature requires TDLOFD-001012 UL Interference Rejection Combining.
−
Phase II of this feature requires Phase I of this feature.
−
Enhanced 4R UL CoMP requires smart IRC.
Others None
3.2.22 TDLOFD-081207 UL CoMP based on Coordinated BBU Availability This feature is:
Available in macro eNodeBs as of LTE TDD eRAN8.1.
Not available in LampSite eNodeBs.
Not available in micro eNodeBs.
Summary This feature, together with TDLOFD-001066 Intra-eNodeB UL CoMP, implements joint reception in intra- or inter-BBU cells in multi-BBU interconnection scenarios.
Benefits This feature increases the uplink throughput of cell edge users (CCEs) and some cell center users (CCUs) in intra- or inter-BBU cells. Inter-BBU UL CoMP increases the proportion of UL CoMP UEs and improves the performance of these UEs, compared with intra-BBU UL CoMP.
Description This feature can use the antennas of inter-BBU cells to receive signals from a UE. The serving cell and coordinating cells are set up in different BBUs and need to exchange information through universal switching units (USUs). This feature is applicable in the following scenarios:
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Inter-BBU UL CoMP in cells served by RRUs installed on different poles or towers
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Figure 3-3 Inter-BBU UL CoMP
Inter-BBU UL CoMP in cells served by RRUs installed on the same pole or tower
In the preceding scenarios, the RRUs are connected to BBPs in different BBUs, and the BBUs are connected through USUs. This feature supports a maximum of two levels of USUs.
Enhancement In LTE TDD eRAN11.0:
This feature can be used in SFN cells, macro cells.
This feature can preferentially select VoIP users for UL CoMP.
This feature can be deployed on the LBBPd that supports six cells or the UBBPd with one chip supporting six cells.
The eNodeB can automatically adjust the reporting interval of UL CoMP A3 measurement reports and disable UL CoMP when the main control board's CPU is flow controlled. The two functions reduce resource consumption for UL CoMP when the network is heavily loaded.
This feature can be used in three cells when this feature's switch and the 3-cell UL CoMP switch are both turned on. When this feature uses the antennas of three cells to receive signals from a UE, it provides higher gains than the function that uses the antennas of one or two cells to receive signals from a UE. Figure 3-4 compares 2-cell UL CoMP (left) and 3-cell UE CoMP (right).
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Figure 3-4 2-cell UL CoMP (left) and 3-cell UE CoMP (right)
Dependency
eNodeB The eNodeB can be a macro, micro (BTS3205E), or LampSite eNodeB. The BBU can be a BBU3900 or BBU3910. The BBP model can be LBBPd, UBBPd, or UBBPe. The cells selected for UL CoMP must meet the following conditions:
−
If the cells are geographically adjacent inter-BBU cells, they must be configured with intra-frequency handover relationships and their physical cell identifiers (PCIs) must be different.
−
If the cells are inter-BBU cells, they must have different eNodeB IDs.
−
The cells must have the same frequency, bandwidth, cyclic prefix (CP) type, and receive mode (4R or 8R).
eCoordinator None
UE None
Transport network None
Core network None
OSS None
Other features −
TDLOFD-001012 UL Interference Rejection Combining
−
TDLOFD-001066 Intra-eNodeB UL CoMP
Others None
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3.3 QoS 3.3.1 TDLOFD-001026 Optional uplink-downlink subframe configuration 3.3.1.1 TDLOFD-00102601 uplink-downlink subframe configuration type 0 Availability This feature is:
Available in macro eNodeBs as of LTE TDD eRAN3.1.
Available in micro eNodeBs as of LTE TDD eRAN6.1.
Not available in LampSite eNodeBs.
Summary eNodeBs support different uplink-downlink subframe configurations.
Benefits This feature allows operators to flexibly configure the uplink-downlink subframe ratio based on different service requirements.
Description eNodeBs support different uplink-downlink subframe configurations specified in 3GPP TS 36.211. Type 0: The ratio of uplink subframe to downlink subframe is 3:1. When this configuration is used, the throughput of uplink traffic is larger than downlink traffic, such as in video surveillance. Table 3-4 shows uplink-downlink subframe configuration type 0. Table 3-4 Uplink-downlink subframe configuration type 0 Uplink-d ownlink configur ation
Downlin k-to-Upl ink Switch-p oint periodici ty
Subframe Number 0
1
2
3
4
5
6
7
8
9
0
5 ms
D
S
U
U
U
D
S
U
U
U
In the preceding figure, D denotes the subframe reserved for downlink transmissions, U denotes the subframe reserved for uplink transmissions, and S denotes a special subframe that consists of the downlink pilot timeslot (DwPTS), guard period (GP), and uplink pilot timeslot (UpPTS).
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Enhancement None
Dependencies This feature cannot coexist with following features: TDLOFD-001077 MU-Beamforming
3.3.1.2 TDLOFD-00102602 uplink-downlink special subframe configuration type 4 Availability This feature is:
Available in macro eNodeBs as of LTE TDD eRAN1.0.
Available in micro eNodeBs as of LTE TDD eRAN6.1.
Not available in LampSite eNodeBs.
Summary eNodeBs support different special subframe configurations (DwPTS, GP, and UpPTS lengths).
Benefits This feature allows operators to flexibly configure special subframe configurations according to application scenarios, such as a different cell radius.
Description eNodeBs support different special subframe configurations (DwPTS, GP, and UpPTS lengths) specified in 3GPP TS 36.211. Type 4: The length ratio of DwPTS to GP to UpPTS is 12:1:1 when eNodeBs use normal cyclic prefix (CP). The length ratio of DwPTS to GP to UpPTS is 3:7:1 when eNodeBs use extended CP. Table 3-5 and Table 3-6 list special subframe configuration type 4. Table 3-5 Special subframe configuration type 4 (normal CP) Special Subframe Configuration
Normal CP DwPTS
GP
UpPTS
4
26336Ts
2192Ts
2192Ts
Table 3-6 Special subframe configuration type 4 (extended CP) Special Subframe
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Extended CP
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Configuration
DwPTS
GP
UpPTS
4
7680Ts
17920Ts
2560Ts
Enhancement None
Dependency None
3.3.1.3 TDLOFD-00102603 uplink-downlink special subframe configuration type 5 Availability This feature was introduced in LTE TDD eRAN2.0.
Summary eNodeBs support different special subframe configurations (DwPTS, GP, and UpPTS lengths).
Benefits This feature allows operators to flexibly configure special subframe configurations according to application scenarios, such as a different cell radius.
Description eNodeBs support different special subframe configurations (DwPTS, GP, and UpPTS lengths) specified in 3GPP TS 36.211. Type 5: The length ratio of DwPTS to GP to UpPTS is 3:9:2 when eNodeBs use normal CP. The length ratio of DwPTS to GP to UpPTS is 8:2:2 when eNodeBs use extended CP. Table 3-7 and Table 3-8 list special subframe configuration type 5. Table 3-7 Special subframe configuration type 5 (normal CP) Special Subframe Configuration
Normal CP DwPTS
GP
UpPTS
5
6592Ts
19744Ts
4384Ts
Table 3-8 Special subframe configuration type 5 (extended CP) Special Subframe
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Extended CP
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Configuration
DwPTS
GP
UpPTS
5
20480Ts
5120Ts
5120Ts
Enhancement None
Dependency None
3.3.1.4 TDLOFD-00102604 uplink-downlink special subframe configuration type 6 Availability This feature is:
Available in macro eNodeBs as of LTE TDD eRAN6.0.
Not available in micro eNodeBs.
Not available in LampSite eNodeBs.
Summary eNodeBs support different special subframe configurations (DwPTS, GP, and UpPTS lengths).
Benefits This feature allows operators to flexibly configure special subframe configurations according to application scenarios, such as a different cell radius.
Description eNodeBs support different special subframe configurations (DwPTS, GP, and UpPTS lengths) specified in 3GPP TS 36.211. Type 6: The length ratio of DwPTS to GP to UpPTS is 9:3:2 when eNodeBs adopt normal CP. The length ratio of DwPTS to GP to UpPTS is 9:1:2 when eNodeBs adopt extended CP. Table 3-9 and Table 3-10 special subframe configuration type 6. Table 3-9 Special subframe configuration type 6 (normal CP) Special Subframe Configuration
Normal CP DwPTS
GP
UpPTS
6
19760Ts
6576Ts
4384Ts
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Table 3-10 Special subframe configuration type 6 (extended CP) Special Subframe Configuration
Extended CP DwPTS
GP
UpPTS
6
23040Ts
2560Ts
5120Ts
Enhancement None
Dependency The RRU3702, RRU3232, and RRU3233 do not support this feature. This feature does not apply to micro eNodeBs.
3.3.1.5 TDLOFD-00102605 uplink-downlink special subframe configuration type 9 Availability This feature is:
Available in macro eNodeBs as of LTE TDD eRAN7.0.
Not available in micro eNodeBs.
Not available in LampSite eNodeBs.
Summary The eNodeB supports special subframe configuration 9.
Benefits More special subframe configurations are available.
Description In compliance with 3GPP Release 11, eNodeBs additionally support special subframe configuration 9 when the normal cyclic prefix (CP) is used. Table 3-11 lists the special subframe configurations supported by eNodeBs. Table 3-11 Special subframe configurations supported by eNodeBs Special Subframe Configuration
Normal CP DwPTS
GP
UpPTS
DwPTS
GP
UpPTS
0
3
10
1
3
8
1
1
9
4
8
3
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Extended CP
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2
10
3
9
2
3
11
2
10
1
4
12
1
3
7
5
3
9
8
2
6
9
3
9
1
7
10
2
5
5
2
8
11
1
–
–
–
9
6
6
–
–
–
2
2
2
Enhancement None
Dependency Special subframe configuration 9 requires UE support.
3.3.2 TDLOFD-001006 UL 64QAM Availability This feature is available as of LTE TDD eRAN1.0.
Summary UL 64QAM enhances uplink modulation and allows UEs in excellent radio conditions to transmit data to the eNodeB at high data rates.
Benefits This feature increases cell throughput and improves user experience by providing high data rates.
Description UL 64QAM is a complement to Quadrature Phase Shift Keying (QPSK) and 16QAM. UL 64QAM is intended to increase data rates for UEs in excellent radio conditions. If QPSK is used, each symbol carries two information bits; if 16QAM is used, each symbol carries four information bits. By contrast, if 64QAM is used, each symbol carries six information bits. Therefore, 64QAM significantly improves system capacity in the uplink. The eNodeB can select QAM modulation schemes of different orders based on radio conditions. If a UE is located very close to the eNodeB or in excellent radio conditions, the eNodeB can select 64QAM (the highest-order QAM modulation scheme) and allow uplink transmission of large blocks to achieve high data rates.
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Enhancement None
Dependency This modulation scheme applies only to UEs in excellent channel conditions. All category 5 or 8 UEs support UL 64QAM. Category 6 or 7 UEs support UL 64 QAM only when the UEs support 3GPP release 12 and report the supportOf64QAM-UL field.
3.3.3 TDLOFD-110227 Traffic Model Based Performance Optimization Availability This feature is:
Available in macro eNodeBs as of LTE TDD eRAN11.0.
Available in micro eNodeBs as of LTE TDD eRAN11.0.
Available in LampSite eNodeBs as of LTE TDD eRAN11.0.
Summary This feature optimizes the enhanced proportional fair (EPF), a scheduling policy, for non-GBR services considering factors such as the buffered data to be transmitted and the transmission rates over the Uu interface.
Benefits This feature increases the average perceivable data rates for non-GBR services in the uplink and downlink during peak hours, improving user experience.
Description This feature raises the scheduling priorities for "good users" who have small amounts of buffered data to be transmitted and favorable channel conditions (high transmission rates over the Uu interface). In heavy traffic scenarios (for example, when the RB usage is greater than 60%), the traditional PF scheduling algorithm may cause "bad users", who have large amounts of buffered data to be transmitted and poor channel conditions, to occupy a large number of scheduling opportunities. "Good users" who can be quickly scheduled must wait in the queue for long periods and the average perceivable uplink and downlink data rates decrease, reducing user experience. This feature raises the scheduling priorities for "good users" and lowers the scheduling priorities for "bad users." Service performance for "good users" is significantly improved at the little expense of insignificant performance degradation for "bad users." The average perceivable uplink and downlink data rates in peak hours increase and user experience is improved. This feature is supported in cells with a bandwidth of at least 5 MHz.
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Enhancement None
Dependency
eNodeB None
UE None
Transport network None
CN None
OSS None
Other features None
Other requirements This feature is supported in cells with a bandwidth of at least 5 MHz.
3.3.4 TDLOFD-001015 Enhanced Scheduling 3.3.4.1 TDLOFD-00101501 CQI Adjustment Availability This feature was introduced in LTE TDD eRAN1.0.
Summary This feature enhances the conventional AMC scheme by introducing downlink CQI adjustment. It provides additional performance gains.
Benefits This feature brings the following benefits:
Effectively compensates for inaccurate CQI measurement and makes the modulation and coding scheme (MCS) selection more accurate by using a closed-loop mechanism.
Improves system capacity by selecting an accurate MCS.
Allows an adaptive CQI measurement in different scenarios and therefore improves system capacity.
Description Under the conventional AMC scheme, the eNodeB chooses an MCS for a UE based on the reported CQI. As a result, the MCS will mainly change according to the reported CQI. However, the UE measurement error and channel fading affects the accuracy of the reported
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CQI to some extent. MCS selection based on an inaccurate CQI will cause a failure to reach the block error rate (BLER) target in DL transmission. The conventional AMC scheme does not have a closed-loop feedback mechanism to guarantee that the actual BLER reaches the BLER target. The CQI adjustment scheme introduces a closed-loop mechanism to compensate for CQI measurement errors. When an eNodeB selects the MCS for DL transmission, in addition to the CQI and transmit power, the eNodeB also considers the difference between the target BLER and the actual BLER. Note that the actual BLER is calculated based on the closed-loop ACK/NACK that the eNodeB received in DL transmission. In addition, the closed-loop mechanism used in the CQI adjustment scheme allows the eNodeB to instruct a UE to change the BLER target for CQI reporting, which can maximize system throughput.
Enhancement None
Dependency None
3.3.4.2 TDLOFD-00101502 Dynamic Scheduling Availability This feature was introduced in LTE TDD eRAN1.0.
Summary This feature achieves efficient resource utilization. The fairness between different UEs is also considered in the function. The dynamic scheduling algorithm is mainly used for guaranteed bit rate (GBR) and non-GBR services.
Benefits This feature provides the following benefits:
Achieves efficient resource utilization.
Achieves an optimal tradeoff among throughput, fairness, and QoS.
Description This feature achieves efficient resource utilization on a shared channel. In an LTE system, the scheduler allocates resources to the UEs every 1 ms or every one TTI. The scheduling algorithm must achieve a balanced tradeoff between priority differentiation among different services and fairness among users. The UL scheduler uses the token bucket algorithm to control GBR and non-GBR service rates. The proportional fair (PF) algorithm is the basic strategy to ensure scheduling priorities (based on the QCI) among different services. High priorities are assigned to IMS signaling and GBR services. When the congestion indicator from the load control algorithm is received, the scheduler may reduce the guaranteed data rate for GBR services. The scheduler may also consider the input from UL ICIC to reduce interference. QCI is short for QoS class identifier.
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The DL scheduler uses an enhanced scheduling strategy. For GBR services, priorities are calculated based on user channel quality and service packet delay. For non-GBR services, in addition to user channel quality, the scheduled service throughput is also considered for calculating the priority. The enhanced DL scheduler can guarantee an optimal tradeoff among throughput, fairness, and QoS guarantee. Like the UL scheduler, the DL scheduler also considers DL ICIC input to reduce inter-cell interference.
Enhancement In LTE TDD eRAN6.0, when the Uu resources of a cell are congested, there is a possibility that non-GBR services cannot be granted resources because non-GBR services have a lower priority than GBR services. To address this issue, this feature allows a preset proportion of resources to be reserved for non-GBR services, which ensures that there are always resources for downlink non-GBR services.
Dependency None
3.3.5 TDLOFD-081231 Optimized CFI-Calculation-based MCS Index Selection Availability This feature is:
Available in macro eNodeBs as of LTE TDD eRAN8.1.
Available in LampSite eNodeBs as of LTE TDD eRAN8.1.
Available in micro eNodeBs as of LTE TDD eRAN8.1.
Summary This feature enables the eNodeB to use the adaptive CFI to select an accurate MCS index based on the equivalence of spectral efficiency.
Benefits This feature improves system throughput and increases the perceivable service rates for UEs when the adaptive CFI is less than 3.
Description The eNodeB uses the adaptive CFI to calculate the reported CQIs separately for common subframes and special subframes. The calculation is based on the equivalence of spectral efficiency.
Enhancement None
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Dependency None
3.3.6 TDLOFD-081233 Optimized Uplink Resource Allocation Availability This feature is
applicable to Macro from LTE TDD eRAN8.1
not applicable to Micro
applicable to LampSite from LTE TDD eRAN8.1
Summary The Optimized Uplink Resource Allocation feature incorporates the following functions:
Scheduler-controlled power
Optimization on false SR detection in DRX mode
Benefits This feature helps to:
Solve the problem that the PSD of data transmission from the UE declines due to the limitation of the maximum transmit power of the UE, and improve user throughput.
Prevent incorrect scheduling and incorrect adjustment due to false SR detection in DRX mode, reduce the uplink and downlink BLER, improve user throughput, and reduce the call drop rate.
Description When the scheduler-controlled power function is enabled, the RBs allocated by the scheduler outnumber the power-limited RBs and the PSD is lower than that in power control scenarios. The scheduler maintains the PSD to a certain level to ensure that the user throughput does not decrease. The optimization on false SR detection in DRX mode function reduces the incorrect CQI and SRS detection and incorrect scheduling when the eNodeB and UEs are in different DRX states due to false SR detection.
Enhancement None
Dependency
Other features Optimization on false SR detection in DRX mode depends on the TDLBFD-002017 DRX feature.
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3.3.7 TDLOFD-070222 Scheduling Based on Max Bit Rate Availability This feature is:
Available in macro eNodeBs and LampSite eNodeBs as of LTE TDD eRAN7.0.
Not available in micro eNodeBs.
Summary This feature enables eNodeBs to adjust scheduling weights based on aggregate maximum bit rates (AMBRs) or maximum bit rates (MBRs) so that differentiated services can be provided for subscribers.
Benefits Operators can provide differentiated services for subscribers.
Description For wireless broadband service packages, information about the AMBRs for non-GBR bearers is stored in the policy and charging rules function (PCRF) or home subscriber server (HSS), and information about the MBRs of GBR bearers is stored in the PCRF. When a UE accesses the network, the PCRF or HSS notifies the eNodeB of the AMBR and MBR configured for the UE. Then, the eNodeB adjusts uplink and downlink scheduling weights for the UE based on the received AMBR and MBR information. This ensures that the UEs configured with high AMBRs and MBRs are allocated high bandwidths.
Enhancement None
Dependency None
3.3.8 TDLOFD-001028 TCP Proxy Enhancer (TPE) Availability This feature was introduced in LTE TDD eRAN2.0.
Summary A series of enhanced Transmission Control Protocol (TCP) functions adaptive to RAN link characteristics are implemented in the eNodeB. This feature greatly improves the performance of the TCP protocol (derived from the wired network) in the wireless network, therefore enhancing user experience and system efficiency.
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Benefits This feature provides the following benefits:
Mitigates the negative impact of some factors (such as RAN packet loss) on TCP data transmission performance.
Accelerates slow startup and fast retransmission of the server during data transmission.
Greatly improves TCP transmission performance.
Description The Transmission Control Protocol/Internet Protocol (TCP/IP) protocol is used worldwide. It was initially developed for wired transmission and later used in wireless networks. However, wireless networks exhibit some characteristics quite different from the wired network. To mitigate this effect, a number of enhancements have been implemented in the eNodeB. The TPE functionality, implemented in the eNodeB, improves data transmission performance in the wireless network. The TPE processes the TCP/IP packets by adopting the following TCP performance optimization technologies:
ACK splitting The congestion window is updated according to the number of received ACK messages and is expanded by increasing the number of ACK messages. When slow startup occurs, ACK splitting can quickly recover the congestion window. When the sender is in congestion avoidance mode, ACK splitting can accelerate expansion of the congestion window.
Enhancement In LTE TDD eRAN6.0, this feature is enhanced by introducing the uplink ACK control function to prevent bursts of ACKs. In an LTE system, fluctuations over the air interface are inevitable. To ensure correct uplink data transmission, HARQ or automatic repeat request (ARQ) is performed in the uplink to ensure correct data transmission. According to 3GPP specifications for LTE, packets at the Radio Link Control (RLC) layer must be transmitted in sequence. However, the HARQ/ARQ transmission takes at least 8 ms, which may delay the in-sequence transmission of packets. If the transmission is delayed, the packets to be transmitted are buffered, and then burst. For downlink TCP services, ACK packets may also burst. As a result, downlink TCP services burst as well, causing packet loss if the buffer of the transmission equipment is limited. The ACK control function manages the uplink ACK traffic to prevent bursts of ACKs. If the number of ACKs exceeds a threshold, the remaining ACKs are buffered for transmission in the next transmission period. As a result, the ACK control function prevents bursts of downlink data, reduces the packet loss rate, and increases average throughput.
Dependency None
3.3.9 TDLOFD-001027 Active Queue Management (AQM) Availability This feature was introduced in LTE TDD eRAN2.0. Issue 02 (2016-07-30)
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Summary This feature provides an optimized buffer handling method to positively interact with the TCP protocol and shorten the buffering delay.
Benefits This feature decreases the delay of interactive services and improves user experience.
Description In an interactive connection, the packet data to be transmitted is typically characterized by large variations. To address this issue, the buffer is introduced. However, if the buffer is filled or an overflow occurs, data packet loss will result. Currently, TCP is the main transport layer protocol used on the Internet. Packet loss is regarded as link congestion by TCP, and TCP will correspondingly reduce the data transmission rate. The TCP protocol is also sensitive to round trip delay and will act differently if just one packet is lost or if a burst of packets is lost. If a large number of packets are discarded, it may take considerable time for the data rate to increase again, leading to low radio link utilization and causing long delays for users. In addition, if a user is performing concurrent services (such as FTP download and web browsing), the file download as a dominant stream fills the buffers, leading to a long delay for web browsing. This feature can be disabled or enabled.
Enhancement None
Dependency None
3.3.10 TDLOFD-001029 Enhanced Admission Control 3.3.10.1 TDLOFD-00102901 Radio/transport Resource Pre-emption Availability This feature was introduced in LTE TDD eRAN2.0.
Summary This feature enables service differentiation when the network is congested to provide better services for high-priority users.
Benefits This feature provides operators with a method to differentiate users according to priorities. High-priority users can still obtain system resources in cases of resource limitation. In this way, operators can provide better service to those high-priority users.
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Description Pre-emption is a function related to admission control and is the method for differentiating services. It enables operators to provide different services by setting different priorities, which affect the service setup success rate during the service setup procedure. If there are not enough resources and a new service is not admitted to access the network, high-priority users have more chances to access the network than low-priority users, and the resources of low-priority users are pre-empted. Priority information is obtained from the E-RAB-specific QoS parameters, including the allocation/retention priority (ARP), in the ERAB SETUP REQUEST message. The eNodeB assigns user priority based on ARP values. E-RAB is short for E-UTRAN radio access bearer. Pre-emption is performed if service admission fails due to lack of resources, including S1 transmission resources and radio resources (for example, admission based on the QoS satisfaction rate fails). The attributes of Pre-emption Capability and Pre-emption Vulnerability indicate the capability of pre-empting resources of other services and vulnerability to pre-emption by other services, respectively. Pre-emption is not triggered for a signaling radio bearer (SRB) if resource allocation for SRB fails. Emergency call (for example, E911) service has top priority, and therefore always has pre-emption capability. In general, common services cannot pre-empt the resources for SRBs, emergency calls, or IMS signaling.
Enhancement In LTE TDD eRAN6.0, this feature allows resource pre-emption when the number of UEs that have accessed cells reaches the maximum number of UEs supported by an eNodeB. With this enhancement, high-priority services and services that must be guaranteed according to local laws and regulations can pre-empt the resources of common services. An eNodeB allows RRC connections to be established for all UEs that initially access the network. During E-RAB setup, the eNodeB enables high-priority services and emergency calls to pre-empt the resources of common services. The eNodeB selects high-priority services and emergency calls based on ARP values, and selects common services, whose resources are to be pre-empted, in the following sequence: non-GBR services on unsynchronized UEs, non-GBR services on synchronized UEs, and low-priority GBR services.
Dependency This feature requires the core network to bring the ARP IE to eNodeB during E-RAB assignment procedure so that the eNodeB can obtain service priorities with those E-RAB parameters.
3.3.11 TDLOFD-001054 Flexible User Steering 3.3.11.1 TDLOFD-00105401 Camp & Handover Based on SPID Availability This feature was introduced in LTE TDD eRAN3.0.
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Summary This feature is used in the scenarios under which the operator wants to control the mobility of an UE to make it camp on, redirect or handover to a suitable cell. The priorities for the cell selection is predefined and configured to eNodeB through SPID (Subscriber Profile ID for RAT/Frequency Priority).
Benefits Operators can make its subscribers to camp in, redirect or handover to a suitable RAT (a cell of LTE/UMTS/GSM) or frequency (a cell of LTE) based on the service characteristics. For example, for a data centric subscriber, a LTE cell will be the more suitable selection than an UMTS cell or a GSM cell; for a voice centric subscriber, a GSM cell or an UMTS cell will be the more suitable selection than a LTE cell; UEs can return to their home public land mobile networks (HPLMNs) when they move to the boundaries between roaming areas and non-roaming areas. This way, operators can customize different camping policies for UEs.
Description The SPID is an index referring to user information (for example, mobility profile and service usage profile). The information is UE specific and applies to all its Radio Bearers. This index is mapped by the eNodeB to locally defined configuration in order to apply specific RRM strategies (for example, to define RRC_IDLE mode priorities and control Inter-RAT/inter frequency redirection/ handover in RRC_CONNECTED mode). In RRC_IDLE mode, UE can camp in a cell with its suitable RAT or frequency. In RRC_CONNECTED mode, when load balance or overload control triggers an inter-frequency or Inter-RAT handover or redirection, eNodeB will choose a suitable target from the cells according to the priorities indexed by its SPID. In addition, when UE finish its service, eNodeB can release it into a suitable cell according to its SPID priority. For UE without SPID, when overload happens, the UE could also be redirect to a suitable cell according to common priority and overload information. This way, operator can configure and push subscribers into the suitable cell according its subscription. For example: a dongle user usually stays in a LTE high frequency band for a high service rate; a VoIP user is prior to stay in a LTE low frequency band to guarantee the continuous coverage; UEs with a specific SPID can return to their HPLMNs from another operator's network by using the PS handover, circuit switched fallback (CSFB), or single radio voice call continuity (SRVCC) procedure.
Enhancement
LTE TDD eRAN8.1 The "enhanced policy of SPID-specific handover back to the HPLMN" is introduced, which enables UEs with a specific SPID to return to their HPLMNs by using the PS handover, CSFB, or SRVCC procedure when they move to the boundaries between roaming areas and non-roaming areas. The "enhanced policy of SPID-specific handover back to the HPLMN" is controlled by the SPID-based Select PLMN Algo Switch parameter. −
When this parameter is set to ON(On), the enhanced policy is enabled. After the MME sends the SPID of a UE to the eNodeB: If all neighboring cells on a specific frequency are not allowed to serve as candidate cells for handovers during roaming, the eNodeB checks whether the PLMN of these
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neighboring cells is on the HPLMN list corresponding to the UE's SPID (the list is configured by the SpidHPlmnList MO). If it is, the eNodeB sends measurement information about that frequency to the UE. If it is not, the eNodeB does not send measurement information about that frequency to the UE. If a neighboring cell on a specific frequency is allowed to serve as a candidate cell for handovers during roaming, the eNodeB sends measurement information about that frequency to the UE, regardless of whether the PLMN of the neighboring cell is on the HPLMN list corresponding to the UE's SPID. −
When this parameter is set to OFF(Off), the enhanced policy is disabled.
Dependency
CN It depends on SAE to support the SPID configuration.
Other features The SPID-specific load-based handover policy in this feature requires TDLOFD-001032 Intra-LTE Load Balancing or TDLOFD-001044 Inter-RAT Load Sharing to UTRAN or TDLOFD-001045 Inter-RAT Load Sharing to GERAN. The SPID-specific handover back to the HPLMN policies in this feature require TDLBFD-00201802 Coverage Based Inter-frequency or TDLOFD-001019 PS Inter-RAT Mobility between E-UTRAN and UTRAN.
Others GSM/UMTS network should support this functionality to avoid ping-pong handovers.
3.3.11.2 TDLOFD-00105402 WBB Subscriber Identification and Specified QoS Guarantee Availability This feature is:
Available in macro eNodeBs as of LTE TDD eRAN11.0.
Available in micro eNodeBs as of LTE TDD eRAN11.0.
Available in LampSite eNodeBs as of LTE TDD eRAN11.0.
Summary During network planning, operators specify SPIDs to be used by WBB UEs, and configure the SPIDs on the home subscriber server (HSS), mobility management entity (MME), and eNodeB for UE identification. When uplink and downlink bearers are set up for a WBB UE, the MME includes the UE's SPID in the S1AP_INITIAL_CONTEXT_SETUP_REQ message sent to the eNodeB. The eNodeB derives the SPID from the message. If the derived SPID is the same as a WBB-service-specific SPID configured on the eNodeB, the eNodeB identifies the WBB UE. When WBB UEs access a network, the eNodeB provides flexible differentiated services, including scheduling, discontinuous reception (DRX), and handover processing, to ensure user experience of WBB and mobile broadband (MBB) services.
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Benefits
Using idle LTE air interface resources in low-PRB-usage areas, such as suburbans or rural areas, operators develop WBB services, which improves the LTE spectral efficiency, increases profits, and helps operators to preempt the broadband markett.
The WBB solution includes the following functions: scheduling priorities for WBB UEs, SPID-specific DRX policy, SPID-specific intra- and inter-frequency handover processing, and WBB and MBB UE transfer for mobility load balancing (MLB). These features enable operators to provide differentiated services to ensure WBB service development and mobile broadband (MBB) user experience.
Description With this feature, eNodeBs identify WBB UEs based on the SPIDs, and provide flexible differentiated services for WBB UEs, including the following policies:
WBB UE scheduling priority: To ensure differentiated service provision for WBB and MBB UEs, the scheduling priority of WBB UEs must be adjusted to ensure that the service experience of MBB UEs is preferentially guaranteed. The following formula applies to the adjustment of the scheduling priority for non-GBR services for the WBB UEs: WBB_Priority = MBB_Priority x CoeffWBB In this formula: WBB_Priority indicates the WBB UE scheduling priority. MBB_Priority indicates the MBB UE scheduling priority. CoeffWBB indicates the WBB UE scheduling priority weight coefficient, which is used for adjusting the scheduling weight of WBB UEs to MBB UEs.
SPID-specific DRX policy: In most cases, WBB UEs have fixed locations and connect to an external power supply, not sensitive to power consumption. Therefore, discontinuous reception (DRX) can be disabled to optimize the WBB UE scheduling delay and service experience.
SPID-specific intra- and inter-frequency handover processing: In most cases, WBB UEs have fixed locations and operators expect no WBB UE mobility. Therefore, intra- and inter-frequency handover threshold offset factors are used for WBB UEs to suppress their handovers. In this way, WBB service stability can be improved.
Enhancement None
Dependency This feature requires the following features:
TDLOFD-001054 Flexible User Steering: WBB UEs are identified based on the SPID, and therefore the WBB subscriber identification and specified QoS guarantee feature requires the flexible user steering feature.
TDLOFD-001015 Enhanced Scheduling: QoS parameters related to the WBB UE scheduling priority involve scheduling modules, and therefore the WBB subscriber identification and specified QoS guarantee feature requires the enhanced scheduling feature.
This feature is not compatible with TDLOFD-001133 Multi Operators SPID Policy.
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3.3.12 TDLOFD-001059 UL Pre-allocation Based on SPID Availability This feature was introduced in LTE TDD eRAN3.0.
Summary Operators can configure a suitable SPID on the core network for each UE. When a UE accesses the network, its SPID is transmitted to the eNodeB. Based on the SPID, the eNodeB enables or disables the UL pre-allocation for the UE.
Benefits Operators can assign different UL pre-allocation capabilities for different UEs. UL pre-allocation is used for light-loaded cells to decrease the latency for a certain UE.
Description The SPID is an index of user information (such as the mobility profile and service usage profile). The information is UE-specific and applies to all its radio bearers. The eNodeB maps this index to locally defined configuration to apply specific RRM policies. The UL pre-allocation functionality allocates PUSCH RBs to a UE in a light-loaded cell even if the sending buffer of the UE is empty. This feature allows the UE to quickly obtain the transmission chance and accelerates the ACK of a DL RRC signaling message. UL pre-allocation decreases UE transmission delay but increases UE power consumption. Operators can modify related parameters to achieve an optimal tradeoff between transmission delay and power consumption.
Enhancement None
Dependency The SAE must support the SPID configuration.
3.3.13 TDLOFD-001109 DL Non-GBR Packet Bundling Availability This feature was introduced in LTE TDD eRAN6.0.
Summary This feature introduces delay control and bundles downlink packets before transmission.
Benefits This feature provides the following benefits: Issue 02 (2016-07-30)
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Reduces PDCCH overhead and increases PDCCH capacity.
Meets the delay requirements of best effort (BE) services and increases the eNodeB throughput when both GBR and non-GBR services are in use.
Description This feature primarily introduces delay control for BE services. When the network load is light and resources for control and traffic channels are sufficient, the eNodeB does not perform delay-based downlink packet bundling. If the packet delay increases with the network load, the eNodeB bundles downlink packets to reduce PDCCH overhead to improve BE service quality. The eNodeB also increases throughput when users are performing both GBR and non-GBR services.
Enhancement None
Dependency None
3.4 Smart Phone Optimization 3.4.1 TDLOFD-001105 Dynamic DRX 3.4.1.1 TDLOFD-00110501 Dynamic DRX Availability This feature was introduced in LTE TDD eRAN6.0.
Summary Many smartphone applications use a few small packets or heartbeat packets. These applications require the network to frequently reestablish radio resource control (RRC) connections, causing signaling storms and ever-increasing UE power consumption. Dynamic DRX enables smartphones to reduce their consumption of UL resources and energy when using a few small packets or heartbeat packets.
Benefits This feature reduces the following:
Amount of signaling generated when UEs frequently switch between the RRC_CONNECTED and RRC_IDLE modes. This helps prevent signaling storms.
Consumption of PUCCH and SRS resources.
UE power consumption.
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Description Rich LTE applications increase smartphone service traffic, power consumption, and signaling resource consumption, which imposes new requirements on UE power saving techniques.
Many smartphone applications use a few small packets or heartbeat packets. After these service sessions end, smartphones enter the RRC_IDLE mode to save battery power.
However, for most services, smartphones remain online by periodically sending heartbeat packets to the corresponding application servers. These heartbeats and other instant service messages require networks to frequently reestablish connections and therefore consume a large amount of signaling resources.
When these services are used, networks can increase the time the smartphones remain in RRC_CONNECTED mode. However, the smartphones consume more power.
Against this backdrop, Huawei introduces dynamic DRX to reduce smartphone consumption of signaling resources and power. Dynamic DRX provides the following functions:
Keeps smartphones in RRC_CONNECTED mode to reduce signaling.
Enables smartphones to quickly enter the UL out-of-synchronization state to reduce PUCCH resource consumption.
Configures DRX parameters for the UL out-of-synchronization state with a longer DRX cycle to reduce UE power consumption.
Enhancement None
Dependency This feature requires TDLBFD-002017 DRX.
3.4.1.2 TDLOFD-00110502 High-Mobility-Triggered Idle Mode Availability This feature is:
Available in macro eNodeBs as of LTE TDD eRAN6.0.
Not available in micro eNodeBs.
Not available in LampSite eNodeBs.
Summary Moving UEs frequently perform handovers if they continue to process services. If the signaling increase due to frequent UE handovers is greater than the signaling reduction gained by UEs staying in the always-online state, this feature enables UEs to enter the idle mode to prevent signaling bursts.
Benefits This feature reduces the number of handovers and minimizes the impact of handover signaling on network stability.
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Description This feature provides the following functions:
Checks whether always-online UEs are in the high-mobility state.
Supports feature performance monitoring.
Enhancement None
Dependency This feature requires TDLOFD-001105 Dynamic DRX.
3.4.2 TDLOFD-080202 Intelligent Access Class Control Availability This feature is:
Available in macro eNodeBs as of LTE TDD eRAN8.0.
Available in micro eNodeBs as of LTE TDD eRAN8.0.
Available in LampSite eNodeBs as of LTE TDD eRAN8.0.
Summary This feature performs access class (AC) control when a large number of users access the network simultaneously, such as in New Year party, concert, or gathering. AC control is performed based on the cell congestion state to ensure smooth access of UEs and prevent a sharp increase in signaling load. This feature may affect user experience in network access. Therefore, it is recommended that this feature be enabled only when a large number of users access the network simultaneously.
Benefits This feature controls user access to prevent a sharp increase in signaling load. In addition, this feature relieves cell congestion and improves the experience of users who have accessed the network.
Description As defined in 3GPP specifications, an eNodeB can send AC control parameters in system information block type 2 (SIB2) to UEs in a cell. Based on these parameters, the UEs determine whether they can access the cell. eNodeBs support AC control since eRAN2.1. SIB2 can contain AC control parameters for multiple access types. The access types include mobile-originated (MO) signaling, MO data, emergency call, multimedia telephony voice, multimedia telephony video, and CSFB.
For emergency calls, a parameter is used to specify whether to enable access barring.
For other services, multiple parameters are used to specify the access probability factor, access barring duration, and access barring indicators for UEs of ACs 11 to 15.
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Intelligent AC control is introduced in eRAN8.0. With this feature, the eNodeB can determine whether to start AC control based on the cell congestion state. After AC control is started, the eNodeB dynamically adjusts AC control parameters until cell congestion is relieved. Currently, only intelligent AC control for MO signaling and MO data is supported.
Enhancement In eRAN11.1, the access probability factor adjustment step is configurable.
Dependency
eNodeB None
UE UEs must support the AC control mechanism defined in 3GPP Release 8.
Transport network None
Core network None
OSS None
Other features This feature requires TDLBFD-002009 Broadcast of system information.
Others None
3.5 Inter-RAT Mobility Solution 3.5.1 TDLOFD-001019 PS Inter-RAT Mobility between E-UTRAN and UTRAN Availability This feature was introduced in LTE TDD eRAN2.1.
Summary This feature implements inter-RAT cell selection and reselection between the E-UTRAN and UTRAN and allows UEs to be handed over to a UTRAN cell due to limited cell coverage. If the PS handover is not supported by the current network, the PS redirection between the E-UTRAN and UTRAN is performed for inter-RAT mobility. Moreover, the blind handover is performed if inter-RAT measurements may be omitted (to save time and resources) or are unavailable. PS handovers based on the uplink power are supported. When UE QoS cannot be met in the uplink, the eNodeB can trigger an inter-RAT handover to a UTRAN cell to guarantee QoS.
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Benefits This feature provides the following benefits:
Enables seamless co-existence between E-UTRAN and UTRAN.
Guarantees a smooth evolution from the legacy wireless system to the LTE system.
Provides supplementary coverage for the E-UTRAN using the legacy wireless systems to prevent service drops and provide seamless coverage during initial LTE network deployment.
Improves network performance and user experience.
Description A handover between the E-UTRAN and UTRAN is performed when a UE moves to an area that is covered by the UTRAN but not covered by the E-UTRAN during initial LTE network deployment. In Huawei LTE TDD eRAN1.0, handovers are performed based on coverage by evaluating the DL reference signals, including the RSRP and reference signal received quality (RSRQ) of the E-UTRAN, and the received signal code power (RSCP) or Ec/N0 of the UTRAN. When a UE moves beyond E-UTRAN coverage, the eNodeB determines whether to hand it over from the E-UTRAN to the UTRAN according to its measurement report. After receiving the handover command from the source eNodeB, the UE is handed over to the target UTRAN cell. The inter-RAT measurement of the target cell is gap-assisted for the UE with only one RF receiver. In the serving cell, the inter-RAT measurement is triggered by an event A2 that indicates the DL reference signal quality of the E-UTRAN is worse than the absolute threshold. It is stopped by an event A1 that indicates the DL reference signal quality of the E-UTRAN is better than the absolute threshold. The inter-RAT handover is triggered by an event B1 that indicates the common pilot channel (CPICH) quality, RSCP, and/or Ec/N0 of the UTRAN cells is better than the absolute threshold. After receiving the UE measurement report, the eNodeB determines whether to perform a handover to the UTRAN. In LTE TDD eRAN2.0:
If inter-RAT measurements may be omitted (to save time and resources) or are unavailable, the eNodeB performs a blind handover to implement an inter-RAT handover from the E-UTRAN to the UTRAN. For example, if an E-UTRAN cell is co-sited with a UTRAN cell and covers the same area, operators can configure the UTRAN cell as the target cell of the blind handovers from the E-UTRAN cell. When handover trigger conditions (such as load or service requirements) are met, the eNodeB can hand over the UE by performing a blind handover to the target cell without inter-RAT measurement. Compared with a PS handover, a blind handover consumes less time.
If the legacy UTRAN network or UEs cannot support PS handovers, the eNodeB performs a PS redirection to implement an inter-RAT handover between the UTRAN and E-UTRAN. There is no update requirement for legacy UTRAN and UEs to support PS redirection. During a PS redirection, the carrier frequency information about the target system is contained in the RRCConnectionRelease message, which is the same as the RRC connection release procedure. After the source LTE system releases the RRC connection
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of a UE, cell reselection to the target system is performed based on the carrier frequency information received during the connection release and the reestablishment of a connection to the target system. In summary, a PS-redirection-based handover procedure consists of connection release, frequency reselection, and connection reestablishment. Note that the preceding description applies to UEs in active mode. When a UE is in idle mode, cell selection and reselection are used to search for a new serving cell when the UE is initially powered on. The UE selects an inter-RAT cell based on priority settings. The UE continually performs this procedure when it moves. Cell selection and reselection to an inter-RAT system are usually performed in the following scenarios:
E-UTRAN to UTRAN cell reselection: The UE has initially camped on an E-UTRAN cell. When the UE moves beyond E-UTRAN coverage, the UE must reselect a UTRAN cell if available.
UTRAN to E-UTRAN cell reselection: The UE has initially camped on a UTRAN cell. When the UE enters an E-UTRAN cell and the E-UTRAN is configured with a higher priority, the UE reselects the E-UTRAN cell. The priority information is broadcast in cell system information.
When camping on a cell, the UE regularly searches for a better cell according to the cell reselection criteria. If a better cell is detected, that cell is selected. In general, the LTE system is limited in the uplink transmit power. QoS can sometimes be guaranteed in the downlink, but not in the uplink even if the UE has transmitted data using full power. To guarantee QoS in this scenario, Huawei eNodeBs support uplink-transmission-power-based inter-RAT handover to the UTRAN. When detecting that UE QoS cannot be guaranteed, the eNodeB sends a measurement control message to the UE. When the UE reports B1 event to the eNodeB, the eNodeB determines whether to perform a handover to the UTRAN.
Enhancement In LTE TDD eRAN6.0, the following functions are enhanced:
Connect frequency priority parameter for blind redirections The target frequency for blind redirection to the UTRAN can be selected based on frequency priorities to simplify the neighbor relationship at the initial stage of LTE deployment. After a UE accesses a cell, the UE reports two A2 events based on the signal quality of neighboring cells: −
One event is used to trigger an inter-frequency handover measurement.
−
The other event is used to trigger a blind redirection. If event A2 for blind redirection is reported, the signal quality in the serving cell is inadequate for UE services. During initial LTE network deployment, the neighbor relationship is not configured for the eNodeB. Therefore, the eNodeB performs only blind redirection for the UE.
Differentiating UTRAN and GERAN measurement priorities In coverage-based handover scenarios, different threshold offset configurations for event A2 measurements on the UTRAN and GERAN can differentiate the measurement priorities of these two networks.
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Dependency UEs must support this feature. The UMTS and the core network must support PS handovers from the E-UTRAN and the UTRAN.
3.5.2 TDLOFD-001043 Service based Inter-RAT handover to UTRAN Availability This feature was introduced in LTE TDD eRAN2.1.
Summary This feature allows eNodeBs to set up VoIP services in the UMTS system because the LTE system supports only data services.
Benefits This feature provides the following benefits: Utilizes legacy network resources. Improves LTE system capacity while guaranteeing QoS. Decreases the service drop rate and the possibility of system overload.
Description When a UE requests VoIP service setup, the eNodeB sends an inter-RAT measurement control message instructing the UE to execute the measurement. When the UE reports event B1 to the eNodeB, the eNodeB determines whether to set up the service in the UMTS according to the RAB-QCI-based handover policies.
Enhancement None
Dependency UEs must support both LTE TDD and UMTS. This feature depends on the RAB QCI, which helps to determine whether to execute a handover. This feature requires TDLOFD-001019 PS Inter-RAT Mobility between E-UTRAN and UTRAN.
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3.5.3 TDLOFD-001072 Distance based Inter-RAT handover to UTRAN Availability This feature was introduced in LTE TDD eRAN3.0.
Summary Huawei LTE eNodeBs support distance-based handovers from the E-UTRAN to the UTRAN.
Benefits This feature improves user experience.
Description When moving beyond the serving eNodeB's coverage area at frequency F1, the user may still experience a relatively strong signal from F1. This prevents the A2 event from triggering an inter-RAT handover to the UTRAN, even though the neighboring UTRAN signal is much better than that from F1. To ensure the best user connection, a distance-based handover to the UTRAN is employed. When the distance-based handover algorithm is used, the eNodeB must continuously measure the distance to each UE based on the TA measurement. When the distance exceeds the distance threshold specified by the operator, the inter-RAT gap-assisted measurement of the neighboring UTRAN cell is triggered to find an optimal handover candidate to improve user performance.
Enhancement None
Dependency This feature does not apply to micro eNodeBs. UEs must support inter-RAT gap-assisted measurements of UTRAN cells. This feature requires TDLOFD-001019 PS Inter-RAT Mobility between E-UTRAN and UTRAN.
3.5.4 TDLOFD-001078 E-UTRAN to UTRAN CS/PS Steering Availability This feature was introduced in LTE TDD eRAN3.0.
Summary Huawei eNodeBs support the prioritized inter-RAT frequency selection based on the provisioned CS and/or PS service-type priorities during handovers from the E-UTRAN to the UTRAN.
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This feature applies to coverage-based and CS-fallback-triggered handovers from the E-UTRAN to the UTRAN.
Benefits This feature is an enhanced LTE mobility feature that provides a flexible prioritized frequency selection method for handovers from the E-UTRAN to the UTRAN. UEs performing different CS and/or PS services can be steered from E-UTRAN to the designated high-priority frequencies of UTRAN according to the operator's network planning and load-balancing preferences.
Description During a coverage-based or CS-fallback-triggered handover from the E-UTRAN to the UTRAN, the eNodeB initiates inter-RAT measurement for the UE that support inter-RAT measurement or performs an inter-RAT blind handover for the UE that cannot perform an inter-RAT measurement. Huawei eNodeB can prioritize UTRAN frequencies based on the types of CS or PS services used by the UE and the CS or PS priority of each frequency, and then send the UE the highest priority frequency for either a blind handover or a blind redirection if the UE does not support inter-RAT handover.
Enhancement This feature is enhanced in LTE TDD eRAN6.0 to differentiate UTRAN CS and PS frequency priorities. This function enables users to configure CS and PS frequency priorities based on operator requirements. In LTE TDD eRAN3.0, two CS and PS frequency priorities are available: high and low. In LTE TDD eRAN6.0, 17 frequency priorities (from 0 to 16) are available, which allow a UE to be preferentially handed over or redirected to a specified UTRAN frequency.
Dependency This feature requires either of the following features:
TDLOFD-001019 PS Inter-RAT Mobility between E-UTRAN and UTRAN
TDLOFD-001033 CS Fallback to UTRAN
3.5.5 TDLOFD-001020 PS Inter-RAT Mobility between E-UTRAN and GERAN Availability This feature was introduced in LTE TDD eRAN2.1.
Summary This feature implements inter-RAT cell selection and reselection between the E-UTRAN and GERAN and allows UEs to be handed over to an inter-RAT GERAN cell due to limited cell coverage. If the PS handover is not supported by the current network, the PS redirection between the E-UTRAN and GERAN is performed for inter-RAT mobility. Moreover, the blind handover is performed if inter-RAT measurements may be omitted (to save time and resources) or are unavailable.
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PS handovers based on the uplink power are supported. When UE QoS cannot be met in the uplink, the eNodeB can trigger an inter-RAT handover to a GERAN cell to guarantee QoS.
Benefits This feature provides the following benefits:
Enables seamless co-existence between E-UTRAN and GERAN.
Guarantees a smooth evolution from the legacy wireless system to the LTE system.
Provides supplementary coverage for the E-UTRAN using the legacy wireless systems to prevent service drops and provide seamless coverage during initial LTE network deployment.
Improves network performance and user experience.
Description A handover between the E-UTRAN and GERAN is performed when a UE moves to an area that is covered by the GERAN but not covered by the E-UTRAN during initial LTE network deployment. In Huawei LTE TDD eRAN1.0, handovers are performed based on coverage by evaluating the DL reference signals, including the RSRP and RSRQ of the E-UTRAN, and carrier received signal strength indicator (RSSI) of the GSM. When a UE moves beyond E-UTRAN coverage, the eNodeB determines whether to hand it over from the E-UTRAN to the GERAN according to its measurement report. After receiving the handover command from the source eNodeB, the UE is handed over to the target GERAN cell. The inter-RAT measurement of the target cell is gap-assisted for the UE with only one RF receiver. In the serving cell, the inter-RAT measurement is triggered by an event A2 that indicates the DL reference signal quality of the E-UTRAN is worse than the absolute threshold. It is stopped by an event A1 that indicates the DL reference signal quality of the E-UTRAN is better than the absolute threshold. The inter-RAT handover is triggered by an event B1 that indicates the carrier RSSI of the GSM is better than the absolute threshold. After receiving the UE measurement report, the eNodeB performs a handover to the GERAN. Huawei eNodeBs also support PS handover between GERAN and E-UTRAN. In addition to PS handovers, Huawei eNodeBs support cell change order (CCO) with or without network assisted cell change (NACC) in LTE TDD eRAN1.0. In LTE TDD eRAN2.0:
If inter-RAT measurements may be omitted (to save time and resources) or are unavailable, the eNodeB performs a blind handover to implement an inter-RAT handover from the E-UTRAN to the GERAN. For example, if an E-UTRAN cell is co-sited with a GERAN cell and covers the same area, operators can configure the GERAN cell as the target cell of the blind handovers from the E-UTRAN cell. When handover trigger conditions (such as load or service requirements) are met, the eNodeB can hand over the UE by performing a blind handover to the target cell without inter-RAT measurement. Compared with a PS handover, a blind handover consumes less time.
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If the legacy GERAN network or UEs cannot support PS handovers, the eNodeB performs a PS redirection to implement an inter-RAT handover between the GERAN and E-UTRAN. During a PS redirection, the carrier frequency information about the target system is contained in the RRCConnectionRelease message, which is the same as the RRC connection release procedure. After the source system releases the RRC connection of a UE, cell reselection to the target system is performed based on carrier frequency information received during the connection release and the reestablishment of a connection to the target system. In summary, a PS-redirection-based handover procedure consists of connection release, frequency reselection, and connection reestablishment.
Note that the preceding description applies to UEs in active mode. In idle mode, cell selection and reselection are used to search for a new serving cell when the UE is initially powered on. The UE selects an inter-RAT cell based on priority settings. The UE continually performs this procedure when it moves. Cell selection and reselection to an inter-RAT system are usually performed in the following scenarios:
E-UTRAN to GERAN cell reselection: The UE has initially camped on an E-UTRAN cell. When the UE moves beyond E-UTRAN coverage, the UE must reselect a GERAN cell if available.
GERAN to E-UTRAN cell reselection: The UE has initially camped on a GERAN cell. When the UE enters an E-UTRAN cell and the E-UTRAN is configured with a higher priority, the UE reselects the E-UTRAN cell. The priority information is broadcast in cell system information.
When camping on a cell, the UE regularly searches for a better cell according to the cell reselection criteria. If a better cell is detected, that cell is selected. In general, the LTE system is limited in the uplink. QoS can sometimes be guaranteed in the downlink, but not in the uplink even if the UE has transmitted data using full power. To guarantee QoS in this scenario, Huawei eNodeBs support uplink-transmission-power-based inter-RAT handover to the GERAN. When detecting that UE QoS cannot be guaranteed, the eNodeB sends a measurement control message to the UE. When the UE reports B1 event to the eNodeB, the eNodeB determines whether to perform a handover to the GERAN.
Enhancement In LTE TDD eRAN6.0, the following functions are enhanced:
Connect frequency priority parameter for blind redirections The target frequency for blind redirection to the GERAN can be selected based on frequency priorities to simplify the neighbor relationship during initial LTE network deployment. After a UE accesses a cell, the UE reports two A2 events based on the signal quality of neighboring cells: −
One event is used to trigger an inter-frequency handover measurement.
−
The other is used to trigger a blind redirection. If event A2 for blind redirection is reported, the signal quality in the serving cell is inadequate for UE services. During initial LTE network deployment, the neighbor relationship is not configured for the eNodeB. Therefore, the eNodeB performs only blind redirection for the UE.
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In coverage-based handover scenarios, different threshold offset configurations for event A2 measurements on the UTRAN and GERAN can differentiate the measurement priorities of these two networks.
Dependency UEs must support this feature. The GERAN and core network must support NACC and PS handovers between the GERAN and E-UTRAN.
3.5.6 TDLOFD-001046 Service based Inter-RAT handover to GERAN Availability This feature was introduced in LTE TDD eRAN2.1.
Summary This feature allows eNodeBs to set up VoIP services in the GSM system because the LTE system supports only data services.
Benefits This feature provides the following benefits: Utilizes legacy network resources. Improves LTE system capacity while guaranteeing QoS. Decreases the service drop rate and the possibility of system overload.
Description When a UE requests VoIP service setup, the eNodeB sends an inter-RAT measurement control message instructing the UE to execute the measurement. When the UE reports event B1 to the eNodeB, the eNodeB determines whether to set up the service in the GERAN according to the RAB-QCI-based handover policies.
Enhancement None
Dependency UEs must support LTE TDD and GSM. This feature depends on the RAB QCI, which helps to determine whether to execute a handover. This feature requires TDLOFD-001020 PS Inter-RAT Mobility between E-UTRAN and GERAN.
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3.5.7 TDLOFD-001073 Distance based Inter-RAT handover to GERAN Availability This feature was introduced in LTE TDD eRAN3.0.
Summary Huawei LTE eNodeBs support distance-based handovers from the E-UTRAN to the GERAN.
Benefits This feature improves user experience.
Description When moving beyond the serving eNodeB's coverage area at frequency F1, the user may still experience a relatively strong signal from F1. This prevents the A2 event from triggering an inter-RAT handover to the GERAN, even though the neighboring GERAN signal is much better than that from F1. To ensure the best user connection, a distance-based handover to the GERAN is employed. When the distance-based handover algorithm is used, the eNodeB must continuously measure the distance to each UE based on the TA measurement. When the distance exceeds the distance threshold specified by the operator, the inter-RAT gap-assisted measurement of the neighboring GERAN cell is triggered to find an optimal handover candidate to improve user performance.
Enhancement None
Dependency This feature does not apply to micro eNodeBs. UEs must support inter-RAT gap-assisted measurements of GERAN cells. This feature requires TDLOFD-001020 PS Inter-RAT Mobility between E-UTRAN and GERAN.
3.5.8 TDLOFD-001021 PS Inter-RAT Mobility between E-UTRAN and CDMA2000 Availability This feature was introduced in LTE TDD eRAN6.0.
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Summary When this feature is enabled, the eNodeB can perform inter-RAT cell selection and reselection or handovers for high rate packet data (HRPD) users between the E-UTRAN and CDMA2000 network.
Benefits This feature provides the following benefits:
Enables co-existence of the E-UTRAN and CDMA2000 network.
Supports a smooth evolution from the CDMA2000 network to the E-UTRAN.
Provides supplementary coverage for the E-UTRAN during initial LTE network deployment to prevent service drops and implement seamless coverage.
Improves network performance and user experience.
Description The PS handover between the E-UTRAN and CDMA2000 network (that is, the HRPD network) is a type of inter-RAT handover. During initial LTE network deployment, this type of handover is performed when a UE moves from an E-UTRAN coverage area to a CDMA2000 coverage area. For a handover from the E-UTRAN to HRPD network, Huawei eNodeB supports both non-optimized and optimized handover mechanisms defined in 3GPP TS 23.402:
During a non-optimized handover, a UE does not pre-register in the HRPD system. When moving beyond the E-UTRAN coverage area, the UE determines whether to perform a handover from the E-UTRAN to the HRPD network based on the measurement results, and then initiates the handover to the target HRPD cell.
During an optimized handover, a UE pre-registers in the HRPD system. When moving beyond the E-UTRAN coverage area, the eNodeB determines whether to perform a handover from the E-UTRAN to the HRPD network based on the UE measurement report. Upon receiving the handover command sent by the eNodeB, the UE initiates a handover to the target HRPD cell.
The UE uses an RF channel to perform the gap-assisted measurement of the target inter-RAT cell. The measurement is triggered by event A2 and stopped by event A1.
When the measurement is triggered, the quality of E-UTRAN downlink reference signals is poorer than a specific absolute threshold.
When the measurement is stopped, the quality of E-UTRAN downlink reference signals is better than the absolute threshold.
The inter-RAT handover parameters can be configured for different services. Huawei eNodeB also supports PS handovers from the CDMA2000 network to the E-UTRAN. However, from an E2E solution point of view, this type of handover depends on the LTE system capabilities and requires that the CDMA2000 system and core network support this type of handover.
Enhancement None
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Dependency UEs must support this feature. The CDMA2000 system and core network must support PS handovers from the CDMA2000 network to the E-UTRAN.
3.5.9 TDLOFD-001111 PS Mobility from E-UTRAN to CDMA2000 HRPD Based on Frequency-specific Factors Availability This feature was introduced in LTE TDD eRAN6.0.
Summary When an operator has multiple CDMA2000 High Rate Packet Data (HRPD) frequencies in one or multiple band classes, this feature enables the eNodeB to hand over or redirect UEs from the E-UTRAN to the CDMA2000 HRPD network based on the frequency-specific factors.
Benefits This feature balances the loads between CDMA2000 HRPD frequencies.
Description An operator owning multiple CDMA2000 HRPD frequencies can specify a handover or redirection factor for each CDMA2000 HRPD frequency. Based on these factors, the eNodeB determines the target CDMA2000 HRPD band class for handover or redirection. The operator can specify the factors for CDMA2000 HRPD frequencies, based on their respective loads. For example, an operator has two CDMA2000 HRPD bands: 800 MHz and 2.1 GHz. Generally, frequencies on the 800 MHz band are more heavily loaded than those on the 2.1 GHz band. To balance the loads between these two bands, the operator sets the factors for frequencies on the 800 MHz band to smaller values than those for frequencies on the 2.1 GHz band. The following figure illustrates another example. In this situation, CDMA2000 HRPD frequencies 1, 2, and 3 are assigned factors 0.7, 1, and 1, respectively. Then the number of UEs that fall back to frequencies 1, 2, and 3 will meet the following condition: Number of UEs in frequency 1:Number of UEs in frequency 2:Number of UEs in frequency 3 = 0.7:1:1
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Figure 3-5 Redirection from the E-UTRAN to the CDMA2000 HRPD network based on frequency-specific factors
Enhancement None
Dependency This feature requires TDLOFD-001021 PS Inter-RAT Mobility between E-UTRAN and CDMA2000.
3.5.10 TDLOFD-001050 Mobility between LTE TDD and LTE FDD Availability This feature was introduced in LTE TDD eRAN2.1.
Summary This feature implements cell selection and reselection between the TDD E-UTRAN and FDD E-UTRAN and allows UEs to be handed over between TDD and FDD cells.
Benefits This feature provides the following benefits:
Enables seamless coverage between TDD and FDD E-UTRANs.
Improves network performance and user experience.
Description Handover functionality is important in cellular telecommunications networks. It is performed to ensure no service interruption. In LTE systems, handovers decrease communication delay, expand coverage, and enhance system performance. Handovers between TDD and FDD E-UTRANs enable seamless coverage between these two networks and improve network performance and user experience. Issue 02 (2016-07-30)
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The handover procedure can be divided into four phases: measurement triggering, handover measurement, handover decision, and handover execution. Upon receiving a UE measurement report, the eNodeB makes a handover decision. If the measurement meets the handover criteria, the eNodeB performs the handover. Cell selection and reselection allow UEs in idle mode to select or reselect a cell to camp on and to receive the most appropriate service support upon session activation in the LTE system. Cell selection and reselection provide supplementary coverage in LTE systems regardless of whether the TDD E-UTRAN or FDD E-UTRAN is deployed.
Enhancement In LTE TDD eRAN6.0, the urgent redirection function has been provided by this feature. After a UE accesses a cell, the eNodeB delivers two sets of event A2 configurations: one is used for triggering measurements and the other is used for triggering urgent redirection. If urgent redirection is triggered by event A2, the signal quality in the serving cell is poor and the serving cell cannot provide services for the UE. In this case, the eNodeB blindly redirects the UE to a neighboring LTE FDD cell.
Dependency UEs and the core network must support this feature.
3.6 High Speed Mobility 3.6.1 TDLOFD-001007 High Speed Mobility Availability This feature is:
Available in macro eNodeBs as of LTE TDD eRAN1.0.
Not available in micro eNodeBs.
Not available in LampSite eNodeBs.
Summary This feature allows eNodeBs to provide services for UEs moving at up to 208 km/h and 305 km/h with good performance. High-speed access is one of the key features in Huawei SingleRAN LTE solutions to provide high-speed coverage.
Benefits This feature provides the following benefits:
Allows Huawei LTE systems to provide good coverage for UEs moving at up to 208 km/h and 350 km/h.
Provides seamless coverage in a high-speed scenario.
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Description This feature enables Huawei LTE systems to operate and perform well in high-speed scenarios. When a UE moves at high speeds, the fast fading effect on the LTE system becomes severe. It is more difficult to achieve the same performance at high-speeds as compared to normal speeds. Huawei LTE TDD eRAN1.0 supports UE velocity up to 208 km/h and 350 km/h, which covers most mobility scenarios in urban areas. The eNodeB must measure the UE mobility speed and refine the channel estimation scheme accordingly. In addition, the MIMO scheme and resource allocation mechanism are adaptively adjusted by the radio resource management (RRM) function to meet high-speed performance requirements. For example, frequency diversity mode is more suitable than frequency-selective scheduling, as is transmit diversity rather than spatial multiplexing for a UE at high speeds.
Enhancement In LTE TDD eRAN6.0, eNodeBs can work in 4T4R mode.
Dependency eNodeBs must work in 4T4R or 2T2R mode. This feature does not apply to micro eNodeBs. Table 3-12 lists the mutually exclusive features. Table 3-12 Mutually exclusive features Mutually Exclusive Feature
TDLOFD-001049 Single Streaming Beamforming
TDLOFD-001061 Dual streaming Beamforming
TDLOFD-001077 MU-Beamforming
Reason In high speed cells, the estimated beamforming (BF) weight cannot reflect current channel conditions due to quick changes. In this case, BF performance has no gain, and therefore BF is not supported.
TDLAOFD-003002 Intra-eNodeB DL CoMP in Adaptive Mode
DL CoMP requires accuracy of BF weight estimation. In high speed cells, the BF weight cannot reflect current channel conditions due to frequent changes. Therefore, DL CoMP is not supported.
TDLOFD-001066 Intra-eNodeB UL CoMP
UL CoMP requires event A3-based measurement reports. In high speed cells, information in event A3-based measurement reports is inaccurate and coordinating cells cannot be updated in time. In this case, UL CoMP has no gain. Therefore, UL CoMP is not supported.
TDLOFD-080203 Coordinated Scheduling based Power Control
In high mobility scenarios, cell load changes so rapidly that the centralized controller cannot respond promptly.
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Mutually Exclusive Feature
TDLAOFD-080405 Out of Band Relay Introduction
TDLAOFD-00100183 Relay Node Identification
Reason The RRN is stationary and therefore it is not applicable to access to high-speed cells.
3.6.2 TDLOFD-080205 Handover Enhancement at Speed Mobility Availability This feature is:
Available in macro eNodeBs as of LTE TDD eRAN8.0.
Not available in micro eNodeBs.
Not available in LampSite eNodeBs.
Summary To ensure sufficient resources for high-speed UEs in high-speed mobility scenarios (such as high-speed railways), this feature provides the following functions:
eNodeBs hand over low-speed UEs out from high-speed cells.
eNodeBs hand over high-speed UEs to high-speed cells, preventing them from being handed over to normal cells.
eNodeBs redirect dedicated network users who exit the dedicated network and initiate services in the public network back to the dedicated network, preventing frequent handovers and improving user experience.
Benefits User experience improves in high-speed mobility scenarios.
Description Generally, a dedicated network is deployed for high-speed mobility scenarios (such as high-speed railways). To prevent low-speed UEs from occupying resources in this network, the eNodeBs enabled with this feature hand over these UEs out of the dedicated network. In addition, the eNodeBs hand over high-speed UEs to cells enabled with the high-speed mobility feature in the dedicated network, preventing them from being handed over to public network cells. This ensures that high-speed UEs can obtain sufficient resources in the dedicated network. As a result, user experience is improved and the value of the dedicated network is maximized.
Enhancement eRAN8.1: High-speed UE handover frequency-based redirection distinguishes between high-speed UEs and low-speed UEs in the public network based on how often handovers are triggered. This feature applies to scenarios in which high-speed railway dedicated network cells and public Issue 02 (2016-07-30)
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network inter-frequency neighboring cells overlap. For high-speed UEs that exit the dedicated network and connect to the neighboring normal cells, handovers are performed frequently in the public network because the coverage range of the normal cells is small, for example, more than three times within 30s. This feature enables the eNodeB to redirect these UEs back to the dedicated network. UEs that are experiencing ping-pong handovers or performing voice services are not redirected back to the dedicated network.
Dependency
Prerequisite feature TDLOFD-001007 High Speed Mobility
Other features Table 3-13 lists the mutually exclusive features.
Table 3-13 Mutually exclusive features Mutually Exclusive Feature
TDLOFD-001049 Single Streaming Beamforming
TDLOFD-001061 Dual Streaming Beamforming
TDLOFD-001077 MU-Beamforming
Reason In high-speed mobility scenarios, the estimated beamforming (BF) weight cannot reflect current channel conditions due to quick channel changes. In this case, BF performance has no gain, and therefore BF is not supported.
TDLAOFD-003002 Intra-eNodeB DL CoMP in Adaptive Mode
DL CoMP depends on accurate BF weight estimation. In high-speed mobility scenarios, the BF weight cannot reflect current channel conditions due to frequent channel changes. Therefore, DL CoMP is not supported.
TDLOFD-001066 Intra-eNodeB UL CoMP
UL CoMP requires event A3-based measurement reports. In high-speed mobility scenarios, information in event A3-based measurement reports is inaccurate and coordinating cells cannot be updated in time. In this case, UL CoMP has no gain. Therefore, UL CoMP is not supported.
TDLOFD-080203 Coordinated Scheduling based Power Control
In high-speed mobility scenarios, cell load changes so rapidly that the centralized controller cannot respond promptly.
TDLAOFD-080405 Out of Band Relay Introduction
TDLAOFD-00100183 Relay Node Identification
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The RRN is stationary and therefore it is not applicable to network access from high-speed cells.
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3.7 Coverage Enhancement 3.7.1 TDLOFD-001009 Extended Cell Access Radius Availability This feature is:
Available in macro eNodeBs as of LTE TDD eRAN6.0.
Not available in micro eNodeBs.
Not available in LampSite eNodeBs.
Summary To improve wireless network coverage, 3GPP TS36.211 has defined five types of preamble formats (0 - 4) for frame structure type 2. For format 0 and format 4, it corresponds to small cell access radius, for format 1, 2 and 3, they correspond to extended cell access radius.
Benefits This feature is used in large cell scenario to extend the cell access radius.
Description This feature provides operator with support of extended cell radius. According to the 3GPP TS36.211, there are five types of preamble format (0-4) for PRACH are defined to support different cell access radius, shown in Table 3-14. Table 3-14 Preamble formats and cell access radius Preamble format
Cell Access Radius
0
About 15km
1
About 70km
2
About 30km
3
About 100km
4
About 1.4km
The extended cell radius consists of format 1, 2 and 3. For format 3, the supported cell access radius is about 100 km, which is used in the large cell scenario to enhance the system coverage.
Enhancement None
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Dependencies The LBBPc cannot support Preamble format 1, 2 and 3.
3.7.2 TDLOFD-001031 Extended CP Availability This feature is:
Available in macro eNodeBs as of LTE TDD eRAN3.0.
Not available in micro eNodeBs.
Not available in LampSite eNodeBs.
Summary The CP is the guard interval used in the OFDM to decrease the interference caused by the multi-path delay. 3GPP TS36.211 defines two types of CP length: normal and extended.
Benefits The normal CP and the extended CP are used in different cell scenarios:
When the multi-path delay is short, normal CP can achieve better system performance.
When the multi-path delay is long, extended CP can achieve better system performance.
Description In both the downlink and uplink, the extended CP is calculated as follows: Extended cyclic prefix: TCP = 512 x Ts Where Ts = 1/(2048 x Df), Df = 15 kHz For normal CP, there are seven symbols available in one slot. For extended CP, there are six symbols available in one slot. The extended CP increases overhead in exchange for larger multi-path capability. The CP length is set in the network planning phase according to the system application scenario.
Enhancement None
Dependency UEs must support the same length of extended CP as the eNodeB. This feature only applies to macro eNodeBs. This feature does not apply to micro eNodeBs. This feature is only supported by the following RF modules: RRU3232, RRU3235, and RRU3252.
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This feature does not work when the eNodeB bandwidth is 5 MHz. This feature cannot be used with the following features:
TDLOFD-001075 SFN
TDLOFD-002008 Adaptive SFN/SDMA
TDLOFD-001098 Inter-BBP SFN
TDLOFD-001080 Inter-BBU SFN
TDLOFD-001081 Inter-BBP Adaptive SFN/SDMA
TDLOFD-001082 Inter-BBU Adaptive SFN/SDMA
TDLOFD-001049 Single Streaming Beamforming
TDLOFD-001061 Dual Streaming Beamforming
TDLOFD-001077 MU-Beamforming
TDLAOFD-003001 DL CoMP Introduction Package
3.8 WBB 3.8.1 TDLOFD-110223 Specified Service Carrier Availability This feature is:
Available in macro eNodeBs as of LTE TDD eRAN11.0.
Available in micro eNodeBs as of LTE TDD eRAN11.0.
Available in LampSite eNodeBs as of LTE TDD eRAN11.0.
Summary With the increase of WBB UEs, the network load increases. To ensure the MBB and WBB user experience, operators add specified service carriers that only WBB UEs can camp on to increase network capacity.
Benefits
Using idle LTE air interface resources in low-PRB-usage areas, such as suburbans or rural areas, operators develop WBB services, which improves the LTE spectral efficiency, increases profits, and helps operators to preempt the broadband market.
Operators select specified service carriers that only WBB UEs can camp on for capacity expansion, which reduces the network load and prevents network congestion due to the increasing number of WBB UEs.
Description The following operations are performed to achieve the specified service carrier function:
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Outgoing handover of MBB UEs that access specified service carriers: When a UE accesses, is handed over to, or reestablishes a connection to a cell, the eNodeB checks whether the serving carrier is a specified service carrier. If so, the eNodeB checks
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whether the UE is an MBB UE. For an MBB UE, a carrier attribute-based inter-frequency handover is triggered.
Prohibiting handovers of non-emergency-call MBB UEs to specified-service cells: −
Filters out frequencies whose neighboring frequencies are all used for specified-service cells, when the eNodeB is about to instruct an MBB UE to perform measurements for an inter-frequency handover during a non-emergency-call service.
−
Filters out neighboring cells that are specified-service cells from the target cell list, after the eNodeB receives an intra- or inter-frequency measurement report from an MBB UE using a non-emergency-call service.
−
Filters out specified-service cells from the candidate inter-frequency neighboring cell list, when the eNodeB is selecting a target cell for blind handover of a non-emergency-call MBB UE based on the blind handover priorities of neighboring cells.
−
Filters out frequencies whose neighboring frequencies are all used for specified-service cells, when the eNodeB is selecting a target frequency for blind redirection of a non-emergency-call MBB UE based on the frequency priorities. The frequency priorities used as the selection basis can be those specified for mobility management of RRC_CONNECTED UEs or the intra-RAT frequency priorities specified for SPIDs. If no neighboring cell has been established on a frequency to be filtered out, this frequency is retained for blind redirection.
Enhancement None
Dependency None
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Networking & Transmission & Security
4.1 Transmission & Synchronization 4.1.1 TDLOFD-001076 CPRI Compression Availability This feature is:
Available in macro eNodeBs and LampSite eNodeBs as of LTE TDD eRAN6.0.
Not available in micro eNodeBs.
Summary This feature reduces the common public radio interface (CPRI) bandwidth required by a cell.
Benefits This feature provides the following benefits:
Increases the number of RRUs that can be cascaded on a CPRI port.
Decreases the number of optical fibers.
Reduces eNodeB installation and reconstruction costs.
Description This feature decreases CPRI bandwidth resources required by a cell. More RRUs can be cascaded on a CPRI port without changing the CPRI line rate, cell bandwidth, or number of antennas for the cell. This reduces eNodeB installation and reconstruction costs. When this feature is enabled, the CPRI data on the LBBPd and LBBPc decreases to about 50% and 60% of the original CPRI data, respectively. The extent of reduction is determined by the processing capabilities of the two boards.
Enhancement eRAN7.0 supports CPRI compression when the eNodeB bandwidth is 10 MHz or 20 MHz.
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eRAN8.0 supports CPRI compression when the eNodeB bandwidth is 10 MHz, 15 MHz, or 20 MHz.
Dependency This feature can work only when the eNodeB bandwidth is 10 MHz, 15 MHz, or 20 MHz. This feature does not apply to micro eNodeBs. This feature cannot be used with TDLOFD-001031 Extended CP. RRU3251, RRU3252, RRU3253, RRU3256, RRU3257, RRU3210, RRU3152e, RRU3235, RRU3259, RRU3221E, RRU3273, and RRU3279 support this feature.
4.1.2 TDLOFD-081214 Enhanced CPRI Compression Availability This feature is:
Available in macro eNodeBs as of LTE TDD eRAN8.1.
Not available in micro eNodeBs.
Not available in LampSite eNodeBs.
Summary Compared with CPRI compression, this feature can further reduce the required cell bandwidth.
Benefits With this feature, more cells can be cascaded in a CPRI chain, thereby reducing capital expenditure (CAPEX) spent on eNodeBs, optical fibers, and optical modules.
Description This feature reduces the required cell bandwidth. With this feature, more cells can be cascaded in a CPRI chain without changing the CPRI port line rate, the amount of frequency bandwidth resources, or the number of antennas. In this way, fewer eNodeBs are required for networking, thereby reducing optical fiber costs. When this feature is enabled, the CPRI bandwidth in a cell with a bandwidth of 15 MHz or 20 MHz is reduced by about 33%.
Enhancement None
Dependency This feature requires TDLOFD-001076 CPRI Compression. When this feature is enabled, the eNodeB channel bandwidth must be 15 MHz or 20 MHz. This feature does not work with TDLOFD-001031 Extended CP.
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This feature requires UBBPd or UBBPe. Only RRU3252, RRU3259, and RRU3279 support this feature.
4.1.3 TDLOFD-003002 2G/3G and LTE Co-transmission Availability This feature was introduced in LTE TDD eRAN1.0.
Summary This feature allows LTE co-transmission with legacy networks such as GSM, UMTS, or TD-SCDMA to improve resource utilization and decrease operating expense (OPEX).
Benefits In co-site scenarios, this feature provides the following benefits:
Improves transmission resource utilization.
Decreases operating expense (OPEX), such as transmission resource rental fees.
Description eNodeBs support co-transmission with GSM, UMTS, or TD-SCDMA base stations. During site deployment, an eNodeB may share a site with a GSM, UMTS, or TD-SCDMA base station. In this case, co-transmission facilitates better utilization of transmission resources and reduces OPEX. Figure 4-1 illustrates 2G/3G and LTE co-transmission. Figure 4-1 2G/3G and LTE co-transmission
Co-transmission depends on four sub functions: multiple ports, IP route, DHCP relay, and weighted round robin (WRR) scheduling. They are described as follows:
Multiple ports: eNodeB supports several Ethernet interfaces.
IP route: The data of cascaded base stations is transmitted to the IP network through IP routes on the eNodeB. IP routes can be configured by operators.
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DHCP relay: In general, a cascaded base station functions as the DHCP client and the DHCP server must be located in the same broadcast domain. The base station obtains the IP address with the DHCP function. In the co-transmission scenario, however, the cascaded base station is not located in the same broadcast domain as the DHCP server. DHCP relay provides a method to transfer DHCP messages between different broadcast domains.
WRR scheduling: Ensures fair data transmission between the cascaded base station and eNodeB. Data are scheduled according to a weight, which is computed based on traffic bandwidth. Each base station and eNodeB has a weight and then an opportunity to be scheduled.
Enhancement None
Dependency This feature does not apply to micro eNodeBs. GSM, UMTS, and TD-SCDMA base stations must support the IP protocol.
4.1.4 TDLOFD-003011 Enhanced Transmission QoS Management 4.1.4.1 TDLOFD-00301101 Transport Overbooking Availability This feature was introduced in LTE TDD eRAN1.0.
Summary This feature allows the admission of more users while guaranteeing QoS by using the following mechanisms:
Enhanced admission control mechanism: Transport Admission Control (TAC).
QoS mechanisms: traffic shaping and congestion control.
Benefits This feature increases the number of admitted users.
Description The implementation of this feature requires the following mechanisms:
TAC: Allows the bandwidth for user admission control to be larger than the bandwidth of the physical port. By using this mechanism, operators can set the admission threshold to allow the admission of more users.
Traffic shaping: Guarantees that the total available traffic bandwidth is not larger than the total configured bandwidth. The minimum transmission bandwidth of each resource group supported by eNodeB is 64 kbit/s for dual rate and 32 kbit/s for single rate. The bandwidth granularity is 1 kbit/s.
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Congestion control: Detects congestion. If congestion is detected, a signal is sent to the data source indicating congestion and then selected low-priority packets are discarded.
Enhancement None
Dependency The core network must support this feature because SAE uses the TAC over the S1 interface.
4.1.4.2 TDLOFD-00301102 Transport Differentiated Flow Control Availability This feature was introduced in LTE TDD eRAN1.0.
Summary This feature enhances the following mechanisms:
Admission control: TAC.
Queue scheduling: priority queue (PQ) scheduling and WRR scheduling.
Back-pressure flow control.
Benefits This feature provides users with differentiated services while guaranteeing equitable distribution of bandwidth.
Description Transmission differentiated flow control provides users with differentiated services while guaranteeing equitable distribution of bandwidth.
Equitable distribution of bandwidth: Each admitted user can be allocated some bandwidth.
Differentiation: High-priority users take precedence over low-priority users.
The implementation of this feature requires the following mechanisms:
TAC: In case of GBR services, the bandwidth allocated to services is computed based on the GBR. Otherwise, it is computed based on the default reserved bandwidth (for example, non-GBR services).
Queue scheduling: Services enter PQ and WRR queues based on service priorities. Services that enter the PQ queues have the highest scheduling priority, and services that enter the WRR queues are scheduled according to the weight, which is computed based on the service bandwidth. Each service has a weight and then an opportunity to be scheduled.
Back-pressure flow control: Detects congestion on the S1 interface. If congestion is detected, a signal is sent to the data source indicating congestion and then selected low-priority packets are discarded.
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Enhancement None
Dependency None
4.1.4.3 TDLOFD-00301103 Transport Resource Overload Control Availability This feature was introduced in LTE TDD eRAN1.0.
Summary This feature rapidly enhances transmission stability when transmission resources are unexpectedly overloaded.
Benefits This feature provides protection for the system when transmission resources are unexpectedly overloaded.
Description There are two scenarios of unexpected overload:
The transport bearer bandwidth (the bandwidth available in the system) is greatly increased or decreased. For example, the transmission bandwidth decreases from 20 Mbit/s to 10 Mbit/s because of network failure.
The traffic bandwidth (the bandwidth used in the system) is greatly increased or decreased. For example, the traffic bandwidth rapidly increases from 5 Mb/s to 10 Mb/s.
In either of the preceding scenarios, actions such as releasing low-priority users must be taken to guarantee QoS for high-priority users. The actions to be taken depend on the ARP, which defines whether a user can be released when transmission resources are overloaded.
Enhancement None
Dependency None
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4.1.5 TDLOFD-003012 IP Performance Monitoring 4.1.5.1 TDLOFD-00301201 IP Performance Monitoring Availability This feature was introduced in LTE TDD eRAN1.0.
Summary This feature enhances performance management by providing an E2E network monitoring mechanism and acquiring key performance indicators (KPIs) such as information about traffic volume, packet loss rate, delay, and jitter.
Benefits This feature provides the following benefits:
Allows operators to monitor E2E network performance.
Enhances system maintainability and testability.
Improves system performance.
Description This feature complies with a Huawei proprietary protocol. An eNodeB periodically sends detecting packets to the peer device such as the S-GW, and the peer device returns the response packets. The eNodeB acquires KPIs, such as traffic volume, packet loss rate, delay, and jitter from these response packets. These KPIs allow operators to learn about the network quality and provide a reference for taking actions, such as network optimization and network expansion. In addition, the IP PM feature helps operators to identify whether a fault occurred in transmission network devices or LTE devices when LTE devices such as the eNodeB and S-GW are enabled with IP PM. Furthermore, if all NEs are enabled with IP PM, the fault can be quickly located.
Enhancement None
Dependency The core network must support this feature. This feature cannot be used with TDLOFD-001134 Virtual Routing & Forwarding.
4.1.5.2 TDLOFD-00301202 Transport Dynamic Flow Control Availability This feature was introduced in LTE TDD eRAN1.0.
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Summary According to the network quality detected by IP PM, the transmission dynamic flow control feature can dynamically adjust flow control parameters.
Benefits Flow control parameters are dynamically adjusted to adapt to network quality, which changes dynamically.
Description When network quality is unstable, it is recommended to dynamically adjust flow control parameters, such as bandwidth. This feature provides a method to dynamically adjust QoS parameters according to the network quality detected by IPPM. For example, when the network quality is good, transmission dynamic flow control automatically increases the bandwidth incrementally. Otherwise, it decreases the bandwidth. IP PM provides an E2E network performance monitoring method to acquire information about network quality, such as traffic volume, packet loss rate, delay, and jitter.
Enhancement None
Dependency This feature requires TDLOFD-00301201 IP Performance Monitoring and TDLOFD-00301102 Transport Differentiated Flow Control. This feature cannot be used with TDLOFD-001134 Virtual Routing & Forwarding.
4.1.6 TDLOFD-003018 IP Active Performance Measurement Availability This feature was introduced in LTE TDD eRAN6.1. Appliable to Micro from LTE TDD eRAN8.0
Summary The IP active performance measurement feature complies with the IETF IP PM standards, RFC2678, RFC2680, RFC2681, RFC3393, and the Two-Way Active Measurement Protocol (TWAMP) in RFC5357. IP transmission performance can be detected between an eNodeB and a device that complies with RFC5357 (TWAMP), for example, between an eNodeB and a CN, between an eNodeB and a transmission device (for example, a router), and between an eNodeB and a test device. This feature implements the following functions:
Network performance monitoring When the transmission rate is unstable and the transmission bandwidth dynamically changes, this function can detect the transport network's quality of service (QoS) so
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operators can quickly locate network problems and take corrective measures, such as capacity expansion and network optimization.
Transmission fault diagnosis −
Quickly locates and isolates transmission faults, such as a high packet loss rate or a long delay, using TWAMP.
−
Troubleshoots a transport network on a per segment basis by measuring round-trip network performance between an eNodeB and a transmission device (such as an intermediate router that supports TWAMP), therefore facilitating network maintainability and reducing maintenance costs. TWAMP testing uses User Datagram Protocol (UDP) packet injection, which generates traffic on the transport network and therefore occupies some bandwidth. For example, if 80-byte packets are continuously sent at a rate of 10 packets per second in a test stream, the bandwidth consumption is 6.4 kbit/s.
Benefits This feature offers the following benefits:
Helps operators quickly locate and rectify faults on networks.
Facilitates network maintainability and reduces maintenance costs.
Description Based on the TWAMP protocol, this feature monitors the QoS of the transport network, such as the packet loss rate, round-trip delay, and jitter. The TWAMP architecture is composed of four logical parts: Session-Sender, Session-Reflector, Control-Client, and Server. TWAMP measurement includes testing and negotiation.
Testing is conducted between the Session-Sender and Session-Reflector based on the UDP protocol. The Session-Sender and Session-Reflector function as TWAMP test hosts and exchange UDP packets for testing. The Session-Sender sends test packets to the Session-Reflector and the Session-Reflector responds to the test packets.
Negotiation is conducted between the Control-Client and Server using Transmission Control Protocol (TCP) packets on port 862. The Control-Client and Server exchange TCP packets to manage measurement tasks, for example, to initialize, start, and stop the tasks.
The Session-Sender actively inserts test packets for the Session-Reflector's response. The inserted test packets contain the same Session-Sender IP address, Session-Reflector IP address, UDP port number, and Type-P, and are transmitted in a fixed stream. The Type-P descriptor can be the protocol type, port number, packet length, or DSCP value.
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TWAMP actively inserts test packets on test links and calculates the packet loss rate, delay, and delay variation, and round-trip delay based on fields contained in the test packets. The Session-Sender and Session-Reflector exchange test packets as follows: 1.
The Session-Sender includes sequence numbers and timestamp T1 in the test packets and sends them to the Session-Reflector.
2.
The Session-Reflector records timestamp T2 upon receiving the test packets from the Session-Sender. The Session-Reflector copies the packet sequence numbers and timestamp T1 extracted from the received packets into the corresponding reflected packets, which are then sent to the Session-Sender. The corresponding reflected packets also include the Session-Reflector's transmit sequence numbers and timestamp T3.
3.
The Session-Sender records timestamp T4 upon receiving the response packets from the Session-Reflector and then calculates the number of received packets
This feature supports unauthenticated mode.
This feature uses the following formulas to calculate the packet loss rate and the round-trip delay:
Packet loss rate in a measurement period = Number of lost packets/Number of transmitted packets The number of lost packets is calculated based on the numbers of packets transmitted and received by the Session-Sender and those transmitted by the Session-Reflector.
Round-trip delay = (T2 - T1) + (T4 - T3) = (T4 - T1) - (T3 - T2)
This feature calculates the packet delay variation based on the delays of two adjacent packets.
Enhancement None
Dependency This feature does not apply to micro eNodeBs. The peer devices and CN must support the TWAMP protocol.
4.1.7 TDLOFD-003013 Enhanced Synchronization 4.1.7.1 TDLOFD-00301302 IEEE1588 V2 Clock Synchronization Availability This feature was introduced in LTE TDD eRAN1.0.
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Summary The Precision Time Protocol (PTP) in IEEE1588 defines precision to the microsecond and applies to the standard Ethernet. This feature implements precise synchronization of distributed and independent clocks in measurement and control systems. LTE networks can achieve high-accuracy frequency synchronization and time synchronization between clock servers and eNodeBs. IEEE1588 V2 clock synchronization is an alternative clock solution for GPS clock synchronization.
Benefits Compared with the GPS clock solution, IEEE1588 V2 clock synchronization reduces the network deployment cost for operators and offers easy management and maintenance.
Description
Basic principles Figure 4-2 illustrates the basic principles of IEEE 1588. Figure 4-2 Basic principles of IEEE 1588
The NE with the master clock sends synchronization timing packets to the NE with the slave clock. The intermediate switching device connects to the NE with the master clock and functions as a slave clock to obtain the timing information on the transmission of the master clock. Then, the intermediate switching device functions as a master clock and connects to other devices functioning as slave clocks. The Time Stamp Unit (TSU) implements precise time synchronization to reduce delay and jitter caused by the intermediate switching device and sends accurate timing information. Synchronization processing is shifted to the layer between the physical layer and the MAC layer.
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Synchronization principles
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Figure 4-3 illustrates the synchronization principles of IEEE 1588. Figure 4-3 Synchronization principles of IEEE 1588
The signaling process illustrated in Figure 4-3 is as follows: a.
The clock server (for example, IPCLK1000) periodically sends a Sync message to the eNodeB. The Sync message carries standard time information, such as year, month, date, hour, minute, second, and nanosecond. The eNodeB records T2, which indicates the Sync message arrival time at the eNodeB. The time for sending or receiving the message must be measured and recorded at the underlying physical layer or close to the physical layer to improve clock accuracy. In the IEEE1588 standard, the optional hardware assist techniques are designed to improve clock accuracy. If the Sync message is generated by using hardware assist techniques, the message can also carry the timestamp T1, indicating when the message is sent. If the Sync message delay from the clock server is uncertain, the clock server generates a Follow_UP message, which carries the timestamp T1. The Follow_UP message is optional.
b.
The eNodeB responds with a Delay_req message at T3. The eNodeB records T3. The clock server receives the Delay_req message at T4 and then generates a Delay_resp message that carries the timestamp T4 to the eNodeB. The delay sending the Delay_resp message does not affect T4. Therefore, the Delay_resp message does not require real-time processing.
c.
The eNodeB stores the complete information about T1, T2, T3, and T4. Then, the delay of message exchange between the clock server and the eNodeB is calculated as follows: Delay = [(T4 – T1) – (T3 – T2)]/2
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In principle, the absolute time of the eNodeB is equal to the standard time plus the delay carried in the Sync message.
Enhancement
LTE TDD eRAN2.2 IEEE1588 V2 security in frequency synchronization mode is enhanced by transmitting IEEE1588 V2–related messages on Internet Protocol Security (IPsec) tunnels.
LTE TDD eRAN8.1 Supports the ITU-T G.8275.1 time synchronization protocol, which applies to the interconnection between the eNodeB and the third-party network transmission devices that comply with this protocol in IEEE1588 V2 layer 2 multicast networking mode.
Dependency
eNodeB None
UE None
Transport Network For time synchronization, all devices on the clock relay path must support the IEEE1588V2 standard. For frequency synchronization, there is no requirement for devices on the clock replay path.
CN None
OSS None
Other Features This feature cannot coexist with the feature TDLOFD-001134 Virtual Routing & Forwarding.
Others None
4.1.8 TDLOFD-081213 Inter-BBU Clock Sharing Availability This feature is:
Available in macro and LampSite eNodeBs as of LTE TDD eRAN8.1.
Unavailable in micro eNodeBs.
Applicable only to centralized Cloud BB networking.
Summary This feature enables a reference clock (including GPS/RGPS and 1588v2) to be shared among BBUs. In some scenarios where the GPS reference clock cannot be deployed on BBUs in a cloud, this feature enables the USU to deliver a reference clock to these BBUs, which
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improves BBU clock reliability. The GPS reference clock mentioned in this section includes RGPS.
Benefits This feature resolves the issue that the GPS reference clock cannot be deployed on BBUs in some scenarios, which improves BBU clock reliability.
Description With this feature, the USU delivers the clock of the BBU that has locked the GPS reference clock to other BBUs, including LampSite BBUs. The clock working mode of these BBUs can be set to manual so that these BBUs can synchronize their clock with the GPS reference clock delivered by the USU. Alternatively, the clock working mode can be set to automatic. In this way, the BBUs select a reference clock based on the priorities and availability of reference clocks. If the GPS reference clock delivered by the USU is faulty and the GPS reference clock configured for the BBUs is available, the BBUs automatically synchronize their clock with the configured GPS reference clock. Two GPS reference clocks can be configured for two separate BBUs. The two GPS reference clocks work in active/standby mode. If the active GPS reference clock becomes faulty, BBUs automatically synchronize their clock with the standby GPS reference clock.
Enhancement Enhancement in eRAN11.1: In USU3910-based centralized Cloud BB scenarios, two clock sources working in mutual backup mode are supported, which can be the GPS or RGPS clock for the BBU and the IEEE1588 V2 clock for the second-level USU.
Dependency This feature can be used only in centralized Cloud BB scenarios. Only USU3910s allow the 1588v2 reference clock to be shared among BBUs.
4.1.9 TDLOFD-003016 Different Transport Paths based on QoS Grade Availability This feature was introduced in LTE TDD eRAN2.0.
Summary This feature provides a transmission networking solution that consists of different transport paths to implement different QCI grades.
Benefits This feature provides the following benefits:
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Improves QoE.
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Improves network reliability.
Description This feature provides two logical or physical paths set up between the eNodeB and the MME or S-GW. The transmission network can be configured with two groups of different QCIs that are allocated to two paths with different priorities. Services with a high QCI can be carried on the high-priority path and services with a low QCI can be carried on the low-priority path. This improves QoE. Figure 4-4 Two paths configured between the eNodeB and the MME or S-GW
Different transport paths based on QoS grade can also improve network reliability. When one path fails, the connection is released and new data traffic will be handed over to another path. After the failed path recovers, the related traffic flow can again be transmitted over the original path. Huawei eNodeBs support multiple OAM mechanisms to detect and handle path failures, such as BFD, Ethernet OAM, Ping, ARP and SON.
Enhancement None
Dependency This feature does not apply to micro eNodeBs. The S-GW must support two path configurations.
4.1.10 TDLOFD-001134 Virtual Routing and Forwarding Availability This feature was introduced in LTE TDD eRAN6.0.
Summary This feature allows eNodeBs to connect to different operator networks that may be configured with the same internal IP addresses.
Benefits This feature greatly reduces the capital expenditure (CAPEX) and OPEX of operators.
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Description In a wholesale scenario, an eNodeB connects to each retailer's network, for which the retailer operator has deployed the NEs and independently planned internal IP addresses. When different operator networks are configured with the same internal IP address, this feature allows an eNodeB to connect to the networks. The eNodeB prevents the destination IP address of each route from conflicting with others and independently forwards packets in each routing area. In this way, this feature prevents IP address conflicts between networks without changing the internal IP addresses.
Enhancement None
Dependency This feature does not apply to micro eNodeBs. The EPC and transmission network must support virtual local area networks (VLANs). This feature cannot support the UTRPc. This feature cannot be used with the following features:
TDLOFD-003009 IPsec
TDLOFD-003010 Public Key Infrastructure (PKI)
TDLOFD-00301201 IP Performance Monitoring
TDLOFD-00301302 IEEE1588 V2 Clock Synchronization
TDLOFD-003017 S1 and X2 over IPv6
TDLOFD-003024 IPsec for IPv6
4.1.11 TDLOFD-003017 S1 and X2 over IPv6 Availability This feature was introduced in LTE TDD eRAN3.0.
Summary Huawei eNodeBs support the IPv6 protocol on the S1 and X2 interfaces.
Benefits IPv6 provides a significantly larger address space than IPv4. This expansion provides flexibility in allocating addresses and routing traffic and reduces the number of network address translations (NATs). This feature allows eNodeBs to use the IPv6 protocol over the S1 and X2 interfaces so that eNodeBs can provide services on IPv6 networks.
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Description An eNodeB connects to the EPC through the S1 interface. Two eNodeBs are connected through the X2 interface. Both interfaces are based on a full IP transport stack with no dependency on the legacy SS7 network as used in GSM or UMTS networks. In addition to supporting the S1 and X2 interfaces over the IPv4 protocol stack, this feature allows eNodeBs to support the S1 and X2 interfaces over the IPv6 protocol stack. Figure 4-5 S1 and X2 interfaces over the IPv6 protocol stack
Enhancement None
Dependency This feature does not apply to micro eNodeBs. Peer devices (such as the transmission network and core network) must support this feature. This feature is not compatible with the feature TDLOFD-001134 Virtual Routing and Forwarding.
4.1.12 TDLOFD-003024 IPsec for IPv6 Availability This feature was introduced in LTE TDD eRAN3.0
Summary IPsec ensures transmission security at the IP layer in both IPv4 and IPv6 environments, including data transmitted on the S1 and X2 interface control and user planes, OM plane, and synchronization plane. This feature provides IPsec for the IPv6 protocol stack, ensuring data flow security from or to eNodeBs.
Benefits This feature provides the following benefits:
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Performs protection of confidentiality, integrity, and peer authentication and anti-replay for data transmission based on the IPv6 protocol stack.
Enhances the security of data transmitted over the non-trusted IPv6 transmission network.
Description IPsec is a protocol suite that secures Internet Protocol (IP) communications by authenticating and encrypting each IP packet in a data stream. IPsec also includes protocols for establishing mutual authentication between endpoints at the beginning of the session and negotiation of cryptographic keys to be used during the session. The key characteristics of IPsec for IPv6 are the same as IPsec for IPv4:
Two encapsulation modes: transport mode and channel mode
Two security protocols: Authentication Header (AH) and Encapsulation Security Payload (ESP)
Main encryption methods: NULL, Data Encryption Standard (DES), Triple Data Encryption Standard (3DES), and Advanced Encryption Standard (AES)
Main integrity protection methods: HMAC_SHA-1 and HMAC_MD5 HMAC stands for Hash message authentication code, SHA stands for secure hash algorithm, and MD5 stands for message digest algorithm 5
IPsec for IPv6 was developed specifically for IPv6, and is mandatory in all standard-compliant implementations of IPv6. However, IPv6 is an optional extension of IPv4. When the network equipment (such as the host or SeGW) supports IPv6, IPsec for IPv6 protects data flows between a pair of hosts (such as the client and server), between a pair of SeGWs (such as routers or firewalls), or between an SeGW and a host. SeGW stands for security gateway. In an LTE network, IPsec for IPv6 protects one or more data flows between two eNodeBs, between the eNodeB and S-GW or MME, or between the SeGW and eNodeB.
Enhancement None
Dependency This feature does not apply to micro eNodeBs. Peer devices, such as the S-GW and MME, must support the IPv6 protocol and this feature. This feature is not compatible with the feature TDLOFD-001134 Virtual Routing and Forwarding.
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4.2 Security 4.2.1 TDLOFD-001010 Security Mechanism 4.2.1.1 TDLOFD-00101001 Encryption: AES Availability This feature was introduced in LTE TDD eRAN1.0.
Summary This feature provides confidentiality protection for both signaling and user data between eNodeBs and UEs.
Benefits This feature prevents signaling data and user data from being illegally intercepted and modified.
Description The eNodeB provides encryption for RRC signaling and user data. The encryption function consists of ciphering and deciphering and is performed at the Packet Data Convergence Protocol (PDCP) layer. After receiving the UE context from the EPC, the eNodeB initiates the initial security activation procedure. During RRC connection setup, an encryption algorithm is selected and an encryption key is generated based on the RRC protocol. All radio bearers use the encryption algorithm and key. For example, the configuration is used for the radio bearers carrying signaling data as well as for those carrying user data. The encryption algorithm can be changed by a handover. The encryption key can be changed by a handover or RRC connection setup. The encryption keys for a UE in RRC_CONNECTED mode may be changed by a handover procedure. LTE TDD eRAN1.0 supports the AES encryption algorithm.
Enhancement None
Dependency UEs must support the same encryption algorithm as the eNodeB.
4.2.1.2 TDLOFD-00101002 Encryption: SNOW 3G Availability This feature was introduced in LTE TDD eRAN1.0.
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Summary This feature provides confidentiality protection for both signaling and user data between eNodeBs and UEs.
Benefits This feature prevents signaling data and user data from being illegally intercepted and modified.
Description The eNodeB provides encryption for RRC signaling and user data. The encryption function consists of ciphering and deciphering and is performed at the PDCP layer. After receiving the UE context from the EPC, the eNodeB initiates the initial security activation procedure. During RRC connection setup, an encryption algorithm is selected and an encryption key is generated based on the RRC protocol. All radio bearers use the encryption algorithm and key. For example, the configuration is used for the radio bearers carrying signaling data as well as for those carrying user data. The encryption algorithm can be changed by a handover. The encryption key can be changed by a handover or RRC connection setup. The encryption keys for a UE in RRC_CONNECTED mode may be changed by a handover procedure. LTE TDD eRAN1.1 supports the encryption algorithm SNOW3G with 128 bit keys.
Enhancement None
Dependency UEs must support the same encryption algorithm as the eNodeB.
4.2.1.3 TDLOFD-00101003 Encryption: ZUC Availability This feature was introduced in LTE TDD eRAN6.0.
Summary This feature provides confidentiality protection for both signaling and user data between eNodeBs and UEs.
Benefits This feature prevents signaling data and user data from being illegally intercepted and modified.
Description The eNodeB provides encryption for RRC signaling and user data. The encryption function consists of ciphering and deciphering and is performed at the PDCP layer. After receiving the
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UE context from the EPC, the eNodeB initiates the initial security activation procedure. During RRC connection setup, an encryption algorithm is selected and an encryption key is generated based on the RRC protocol. All radio bearers use the encryption algorithm and key. The encryption algorithm can be changed by a handover. The encryption key can be changed by a handover or RRC connection setup. The encryption keys for a UE in RRC_CONNECTED mode may be changed by a handover procedure. The ZUC algorithm is a word-oriented stream ciphering algorithm. It uses a 128-bit initial key and a 128-bit initial vector (IV) as input, and then provides a key stream of 32-bit words, where each 32-bit word is called a keyword. This key stream can be used for ciphering and deciphering. eRAN6.0 supports the ZUC algorithm.
Enhancement None
4.2.2 TDLOFD-003009 IPsec Availability This feature was introduced in LTE TDD eRAN1.0.
Summary IPsec is used to protect, authenticate, and encrypt data flow for necessary security between two NEs at the IP layer.
Benefits This feature provides the security mechanism, confidentiality, integrity, and authentication between two NEs at the IP layer.
Description Figure 4-6 illustrates IPsec.
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Figure 4-6 IPsec
IPsec provides a framework of open standards dealing with data confidentiality, integrity, and authentication between two NEs. IPsec provides these security services at the IP layer. It uses IKEV1 and IKEV2 for negotiation of protocols and algorithms based on the local policy and to generate the encryption and authentication keys used by IPsec. IKE stands for Internet Key Exchange. IPsec protects one or more data flows between two eNodeBs, between the eNodeB and S-GW or MME, or between the SeGW and eNodeB. The key characteristics of IPsec are as follows:
Two encapsulation modes: transport mode and channel mode
Two security protocols: AH and ESP
Main encryption methods: NULL, DES, 3DES, and AES
Main integrity protection methods: HMAC_SHA-1 and HMAC_MD5
Enhancement None
Dependency The SeGW must be deployed. This feature cannot be used with TDLOFD-001134 Virtual Routing & Forwarding.
4.2.3 TDLOFD-081211 eNodeB Supporting IPsec Redirection Availability This feature is applicable to macro eNodeBs from LTE TDD eRAN8.1.
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Summary This feature supports deploying the IPsec redirection function on the network. When the IKEv2 redirection function is enabled for the eNodeB and SeGW, the SeGW decides whether to continue to provide services for the eNodeB or initiate a redirection to a new SeGW according to the redirection policy. If the eNodeB receives a redirection packet from the SeGW, the eNodeB initiates IKE negotiation with a new SeGW and establishes a new IPsec tunnel.
Benefits
Easier SeGW capacity expansion and lower network configuration complexity
Higher SeGW reliability
Description This feature allows redirecting an eNodeB from the serving security gateway to the target one if the load decision conditions are met or if maintenance is required, so as to improve IPsec tunnel reliability. This feature enables an eNodeB to implement IKE negotiation with different SeGWs using the same IKE configuration and to establish an IPsec tunnel, thereby simplifying SeGW network configuration and reducing network configuration complexity. This feature has the following characteristics:
Compatible with the RFC 5685 protocol, the eNodeB can only serve as an initiator.
Supports initiating a redirection during the IKEv2 Initial exchange phase and IKE_AUTH exchange phase for IKEv2.
During the redirection, the eNodeB supports indicating the target SeGW only through IPV4.
Supports setting the maximum number of redirections within five minutes so as to eliminate the possibility that the eNodeB cannot provide services normally because it is repeatedly redirected due to a configuration error or a malicious attack.
IPsec redirection is not supported when an IPsec link is established using DHCP.
Enhancement None
Dependency
eNodeB The eNodeB must be configured with the UMPT, UMDU, LMPT, or UTRPc board to support this feature.
UE None
Transport Network The SeGW must support RFC 5685 IKEv2 Redirect and IPsec SA-based internal dynamic route generation.
CN None
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OSS None
Other Features Prerequisite Feature: TDLOFD-003009 IPsec.
Others None
4.2.4 TDLOFD-003010 Public Key Infrastructure (PKI) Availability This feature was introduced in LTE TDD eRAN2.0.
Summary PKI provides digital certificate authentication, which is applied to IPsec tunnels between the eNodeB and SeGW, and SSL channels between the eNodeB and OMC.
Benefits This feature improves network security.
Description PKI is a framework to manage digital certificates, which are used to provide authentication between two NEs. Digital certificate management involves creating, storing, distributing, and revoking certificates, and distributing the certificate revocation list (CRL). In general, a PKI system includes the Certificate Authority (CA), Certificate Repository (CR), CRL server, and users to be authenticated. The eNodeB and SeGW are users of the PKI system. The eNodeB interacts with the CA, CR and CRL server with assistance from the U2000. The eNodeB supports the certificate reserved prior to delivery. The certificate format complies with X.509 V3. After the eNodeB is working properly, it supports certificate replacement. Figure 4-7 shows an illustration of the eRAN certificate application scenario.
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Figure 4-7 eRAN certificate application scenario
In LTE TDD eRAN2.0, the eNodeB can update digital certificates automatically on the U2000. In LTE TDD eRAN2.1, this feature is enhanced to support automatic certificate distribution using CMPv2. When CMPv2 is introduced to establish a direct tunnel from the eNodeB to the CA, certificate enrollment and update can be automatically performed, and eNodeB certificate issuing and update are more efficient if a large number of eNodeBs have been deployed. The Certificate Management Protocol (CMP) is an Internet protocol used for X.509 digital certificate creation and management in PKI. An eNodeB can utilize CMP to obtain certificates from the CA. This procedure involves the following CMP message: 1.
initial registration/certification
2.
key pair update
3.
certificate update
The CMP message cross-certification request helps a CA to obtain a certificate signed by another CA. CMP messages are encapsulated in HTTP/HTTPs messages for transmission.
Enhancement None
Dependency Peer devices must support this feature. This feature cannot be used with TDLOFD-001134 Virtual Routing & Forwarding.
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4.2.5 TDLOFD-081206 eNodeB Supporting Multi-operator PKI Availability This feature is applicable to macro eNodeBs from LTE TDD eRAN8.1.
Summary This feature applies to RAN Sharing scenarios so as to securely isolate the services of each operator. After this feature is enabled, if each operator deploys its own PKI server, the eNodeB can load and manage the device certificates issued by multiple PKI servers. The eNodeB establishes an independent security tunnel for each operator based on their respective device certificates, so as to achieve the secure isolation of each operator's services.
Benefits In RAN Sharing scenarios, if each operator deploys its own PKI server, this feature provides an independent security tunnel for each operator so as to achieve the secure isolation of each operator's services.
Description The eNodeB supports loading and managing device certificates and CRL files issued by multiple PKI servers. The following actions are involved:
Certificate application: Each operator uses a Huawei-issued device certificate to apply to its own PKI server for a certificate, and the eNodeB establishes an independent IPsec tunnel for each operator. As shown in Figure 4-8, operator A's PKI server issues certificate A to the eNodeB, and operator B's PKI server issues certificate B to the eNodeB. Then, the eNodeB establishes IPsec tunnels A and B for operators A and B, respectively.
Certificate update: Similarly, each operator's PKI server issues an updated certificate.
Certificate revocation: Similarly, each operator's PKI server can revoke a certificate.
CRL file management: Similarly, the eNodeB can obtain the CRL file on each server. The eNodeB then independently manages each certificate file.
To securely isolate the services of operators, the eNodeB can use their respective device certificates to establish a dedicated IPsec tunnel for each operator.
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Figure 4-8 eNodeB Supporting Multi-operator PKI
Enhancement None
Dependency
eNodeB The eNodeB must be configured with the UMPT, UMDU, LMPT, or UTRPc board to support this feature.
UE None
Transport Network Multiple PKI servers must be deployed in the network.
CN None
OSS None
Other Features None
Others None
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4.2.6 TDLOFD-003014 Integrated Firewall 4.2.6.1 TDLOFD-00301401 Access Control List (ACL) Availability This feature was introduced in LTE TDD eRAN2.0.
Summary ACL is comprised of a series of access control rules. eNodeBs perform packet filtering based on the ACL.
Benefits This feature provides the following benefits:
Helps protect eNodeBs from some attacks.
Helps eNodeBs identify specific types of packets, which must be encrypted and authenticated by IPsec.
Description The system operates based on the rules in ACL. By using the ACL, an eNodeB performs packet filtering according to packet attributes such as source IP addresses, destination IP addresses, source port numbers and destination port numbers. Packet filtering can also be performed based on the type of service (TOS), DSCP, and address wildcard. By using the ACL, operators can select data flows that must be encrypted and authenticated by IPsec, which is applied to guarantee data flow security. In eRAN3.0, the layer-2 filter implements ACL. At layer 2, ACL rules will filter packages by VLAN IDs. The eNodeB can identify the VLAN IDs of the packages, and only packages with the correct VLAN ID will be allowed. In eRAN3.0, eNodeBs support IPsec for IPv6 on the data flows selected based on the ACL.
Enhancement None
Dependency None
4.2.6.2 TDLOFD-00301402 Access Control List (ACL) autogeneration Availability This feature was introduced in LTE TDD eRAN7.0.
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Summary This feature automatically creates access control list (ACL) rules for operation and maintenance (O&M) data, service data, signaling data, data from the Certificate Authority (CA), data from the security gateway (SeGW), and clock data. The automatic ACL rule creation simplifies whitelist configuration for the packet filtering function.
Benefits This feature reduces the complexity of configuring the packet filtering function.
Description This feature works as follows: Enables the eNodeB to obtain the IP address and port number of the peer NE from the O&M link, service link, signaling link, CA, SeGW, and clock objects. Using the IP address and port number, this feature automatically creates ACL rules for the data of these objects. These automatically created ACL rules can ensure that the eNodeB provides basic services. Updates related ACL rules when information about these objects changes. When an O&M function is enabled at the peer end, not at the local end, the eNodeB cannot obtain the IP address of a maintenance packet. To ensure information security, ACL rules for maintenance data must be manually created, even if an O&M function is enabled at both ends.
Enhancement None
Dependency
Dependency on the hardware of a base station controller None
Dependency on eNodeB hardware None
Dependency on the UE None
Dependency on other NEs None
Dependency on the CN None
Dependency on other eRAN features None
4.2.7 TDLOFD-003015 Access Control based on 802.1x Availability This feature was introduced in LTE TDD eRAN2.0.
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Summary eNodeBs support authentication on the transmission network using IEEE 802.1x (Port-Based Network Access Control). Authentication is performed based on the device certificate.
Benefits This feature provides digital certificate authentication between the eNodeB and LAN switch, improving network security.
Description IEEE 802.1x (Port-Based Network Access Control) uses the physical access characteristics of IEEE 802 LAN infrastructures to provide a method of authenticating and authorizing devices attached to a LAN port that has point-to-point connection characteristics. IEEE 802.1x also prevents access to that port if the authentication and authorization process fails. IEEE802.1x authentication and authorization use the framework of Extensible Authentication Protocol (EAP), and are performed for the eNodeB, LAN switch, and AAA server (RADIUS server). Figure 4-9 eRAN 802.1x application scenario
Before the authentication and authorization process is complete, only Extensible Authentication Protocol over LAN (EAPoL) packets can cross the LAN switch. All other packets will be discarded by the LAN switch.
Enhancement None
Dependency Peer devices must support IEEE 802.1x. This feature requires TDLOFD-003010 Public Key Infrastructure (PKI).
4.2.8 TDLOFD-070211 IPsec Redundancy among Multi-SeGWs Availability This feature was introduced in LTE TDD eRAN7.0. This feature is available in micro eNodeBs as of LTE TDD eRAN8.0.
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Summary This feature uses the dead peer detection function to monitor the state of the IPsec tunnel between an eNodeB and an SeGW. If the SeGW becomes faulty, this feature establishes a temporary IPsec tunnel between the eNodeB and another SeGW, thereby improving the reliability of secure networks.
Benefits This feature provides the following benefits:
Quick service recovery
Improved reliability of secure networks
Reduced economic losses for operators
Description This feature works as follows: 1. When an eNodeB detects that an IPsec tunnel between it and the active SeGW is faulty, the eNodeB attempts to initiate an IKE negotiation with each standby SeGW, sequentially, until the eNodeB establishes a temporary IPsec tunnel. Then, the eNodeB switches its services to the temporary tunnel. 2. If the IPsec tunnel between the eNodeB and the active SeGW is restored, the eNodeB switches the services back to the IPsec tunnel and removes the temporary tunnel. This feature applies to intra- or inter-city secure networks.
Enhancement
SRAN11.1 When this feature is enabled, the eNodeB attempts to establish a standby IPsec tunnel with a standby SeGW if the active IPsec tunnel between the base station and the active SeGW is faulty. The eNodeB may initiate IKE negotiations with all standby SeGWs at the same time. To avoid this situation, two parameters are added: IPSec Redundancy Switchover Wait Time and IPSec Redundancy Switchover Random Delay Time. The IPSec Redundancy Switch Back Random Time parameter allows for a random delay before the eNodeB switches back to the active SeGW.
Dependency
eNodeB Only the Ethernet ports on the UMPT, LMPT, and UTRPc support this feature.
UE None
Other NEs Multiple SeGWs are deployed on a network, and routes from the eNodeB to these SeGWs are all reachable.
Core network None
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This feature is mutually exclusive with TDLOFD-001134 Virtual Routing and Forwarding. This feature is dependent on TDLOFD-003009 IPsec.
4.2.9 TDLOFD-070212 eNodeB Supporting PKI Redundancy Availability This feature was introduced in LTE TDD eRAN7.0. Applicable to Micro from LTE TDD eRAN8.0
Summary This feature supports deploying one active and one standby PKI server on a network. If a session between the eNodeB and active PKI server fails, the eNodeB automatically reinitiates a session with the standby PKI server.
Benefits This feature provides the following benefits:
Prevents certificate applications and updates as well as CRL acquisitions from being affected by active server failures
Prevents link failures caused by certificate-related problems
Improves the reliability of PKI-based secure networks
Description In PKI redundancy, you must deploy one active and one standby PKI server on a network and ensure that they synchronize certificate management data between them. If a session between an eNodeB and the active PKI server fails, the eNodeB automatically reinitiates a session with the standby PKI server to continue to apply for and update a certificate and obtain a CRL. The following figure illustrates how this feature works. Figure 4-10 How this feature works
Enhancement None
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Dependency
Dependency on eNodeB hardware The UMPT, LMPT, or UTRPc must be configured to support this feature.
Dependency on UEs None
Dependency on other NEs One active and one standby PKI server must be deployed on a network.
Dependency on the CN None
Dependency on other eRAN features −
This feature and the TDLOFD-001134 Virtual Routing and Forwarding feature are mutually exclusive.
−
This feature is dependent on the TDLOFD-003010 Public Key Infrastructure (PKI) feature.
Professional Services This feature should be used with Huawei professional services for eRAN network design.
4.3 Reliability 4.3.1 TDLOFD-001018 S1-flex Availability This feature was introduced in LTE TDD eRAN2.0.
Summary This feature is part of the MME pool solution, which must be supported by both the eNodeB and the MME. It allows an eNodeB to connect to multiple MMEs simultaneously. In LTE TDD eRAN2.0, Huawei eNodeBs support a maximum of 16 S1 interfaces. One S1 interface can be connected to one or more MMEs.
Benefits This feature provides the following benefits:
Increased S1 interface flexibility.
Increases overall usage of the MME pool capacity.
Improves the performance of load sharing across MMEs in a pool.
Prevents unnecessary EPC signaling when the UE moves within the MME pool area. The served MME of the UE does not change.
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Description Figure 4-11 illustrates the topology between MME pools and eNodeBs. Figure 4-11 Topology between MME pools and eNodeBs
When an eNodeB connects to an MME pool, the eNodeB must determine which MME in the pool will receive UE signaling:
If the UE sends the MME information in an RRC signaling message, the eNodeB will select the MME based on this information.
If the UE does not send the MME information or the registered MME is not connected to the eNodeB, the eNodeB will select an MME in one of the following ways: −
Topology-based MME pool selection The MME is selected based on the network topology to reduce the possibility of MME switching during mobility.
−
Load-based MME selection The MME is selected based on its capacity and load. The eNodeB can be informed of MME capacity during S1 setup. When an MME is overloaded, the eNodeB will limit new UE assignments to the MME according to overload action information, which the MME sends to the eNodeB when overload starts.
Enhancement In LTE TDD eRAN6.0, the priority-based MME selection method is added. When MMEs or the S1 interfaces to MMEs are assigned different priorities, the MME with the highest priority is preferentially selected. If multiple MMEs have the highest priority, the MME with the lowest load among them is preferentially selected. An MME with a low priority is selected only when all high-priority MMEs are faulty or overloaded.
Dependency The MME must support the MME pool function.
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4.3.2 TDLOFD-003004 Ethernet OAM 4.3.2.1 TDLOFD-00300401 Ethernet OAM (IEEE 802.3ah) Availability This feature was introduced in LTE TDD eRAN1.0.
Summary Ethernet OAM (IEEE 803.3ah) provides fault isolation and troubleshooting capabilities for point-to-point (P2) Ethernet services.
Benefits Ethernet OAM is available between two directly connected devices.
Description Ethernet OAM is a protocol at the MAC layer. This protocol facilitates the operation, administration, and maintenance (OAM) of Ethernet. Ethernet OAM includes IEEE 802.3ah and 802.1ag.
802.3ah supports P2P OAM between two directly connected devices.
802.1ag provides the E2E OAM function.
The basic functions supported by IEEE 802.3ah are as follows:
Discovery: OAM session setup procedure. A device periodically sends OAM protocol data units (PDUs) to check whether its peer device supports IEEE 802.3ah.
Remote failure indication: A device sends OAM PDUs to inform its peer device of faults when detected. Faults may include a link fault, dying gasp, or critical event.
Link monitoring: A device supports link bit error rate (such as error frame and error signal) monitoring. When the error rate exceeds a threshold, the device reports the event to the peer device by sending OAM PDUs.
Remote loopback: A sends a loopback control PDU, instructing the peer device to loop back. Loopback helps locate the fault and test link quality.
Enhancement None
Dependency Peer devices must support IEEE802.3ah. Ethernet interfaces are used. This feature cannot be used with TDLOFD-001134 Virtual Routing and Forwarding.
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4.3.2.2 TDLOFD-00300403 Ethernet OAM (Y.1731) Availability This feature was introduced in LTE TDD eRAN6.0.
Summary Ethernet OAM (ITU Y.1731) provides E2E performance monitoring functions that allow operation, administration, and maintenance (OAM) staff to measure different performance counters. It also provides fault management functions (including continuity check) that comply with the IEEE 802.1ag protocol.
Benefits This feature provides the following benefits:
Allows operators to monitor transmission quality and layer-2 network performance.
Helps operators to quickly identify layer-2 connection and performance faults.
Provides more information about network performance, which helps operators to determine whether to upgrade the network.
Description The Ethernet OAM (ITU Y.1731) protocol defines fault management and performance monitoring functions. This section describes only the performance monitoring function. The fault management function defined in the ITU Y.1731 protocol complies with the IEEE 802.1ag protocol. Ethernet OAM (ITU Y.1731) performance monitoring measures Ethernet performance counters including the frame loss ratio, frame delay and frame delay variation. This feature establishes an E2E detection session to monitor Ethernet performance counters based on the following services:
Ethernet frame loss measurement (ETH-LM) collects counter values applying to ingress and egress service frames. The counters maintain a count of transmitted and received data frames between a pair of maintenance association end points (MEPs).
Ethernet delay measurement (ETH-DM) can be used for an on-demand OAM to measure frame delay and frame delay variation. ETH-DM can be performed in two directions, called two-way ETH-DM. Two-way ETH-DM is recommended because one-way ETH-DM requires clock synchronization between two MEPs.
Enhancement None
Dependency Peer devices and core networks must comply with ITU Y.1731. This feature does not apply to micro eNodeBs.
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4.3.3 TDLOFD-003005 OM Channel Backup Availability This feature was introduced in LTE TDD eRAN1.0.
Summary This feature allows an eNodeB to use an alternative OM channel if the primary OM channel is faulty.
Benefits This feature ensures OM channel reliability.
Description In the OM channel backup solution, there are two OM channels: primary and secondary. Each channel is configured with an OM IP address. In general, only the primary channel is activated. When the primary channel is faulty, the secondary channel is activated.
Enhancement None
Dependency The peer devices (transmission network and core network) must support this feature.
4.3.4 TDLOFD-003006 IP Route Backup Availability This feature was introduced in LTE TDD eRAN1.0.
Summary This feature allows an eNodeB to use an alternative IP route if the primary IP route is faulty.
Benefits This feature ensures reliability at the IP layer.
Description Two IP routes can be configured with the same destination IP address but different next-hop addresses and priorities. The route with the higher priority is usually activated. When this route is faulty, the route with the lower priority will be activated (for example, through network ping).
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Enhancement None
Dependency Peer devices must support this feature.
4.3.5 TDLOFD-003007 Bidirectional Forwarding Detection Availability This feature was introduced in LTE TDD eRAN2.0.
Summary Bidirectional Forwarding Detection (BFD) is used to detect faults on IP routes.
Benefits This feature provides the following benefits:
Detects network faults.
Achieves high reliability and availability of Ethernet services.
Helps service providers to provide Ethernet services in a cost-effective way.
Description This feature periodically transmits BFD packets between two nodes to detect IP route connectivity. If no BFD packet is received within a detection period, the connection is faulty and related resumption actions will be automatically triggered, such as IP route switching, to avoid link interruption. This feature can quickly detect the fault and can apply to telecom services on IP networks. eNodeBs support two BFD types:
One-hop BFD There is only one router on the IP path between two NEs. One-hop BFD is used to detect gateway availability when a router is used.
Multi-hop BFD
There is at least one router on the IP path between two NEs. Multi-hop BFD is used to detect the connectivity between two NEs, for example, between two eNodeBs, between the eNodeB and S-GW or MME, and between the eNodeB and transport equipment. The following figure illustrates one-hop and multi-hop BFD application scenarios.
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Figure 4-12 One-hop and multi-hop BFD application scenarios
Enhancement
eRAN11.1 BFD authentication performs security hardening on BFD. It is implemented in eRAN11.1. To initiate a BFD session between the eNodeB and the peer node, the authentication information of each other is required. Once local and peer keys are different, the session is terminated. The eNodeB BFD authentication applies to one-hop BFD, not multi-hop BFD. The session detection mechanism after BFD authentication and the processing after the detection (for example, associating routes) are the same as those for BFD. Security authentication ensures the consistency of both sides of the session and the message integrity, and provides protection against replay.
Dependency
Transport network The peer equipment must support BFD.
4.3.6 TDLOFD-003008 Ethernet Link Aggregation (IEEE 802.3ad) Availability This feature was introduced in LTE TDD eRAN2.0.
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Summary This feature binds several Ethernet links to one logical link.
Benefits This feature provides the following benefits:
Enhances the reliability of Ethernet links between eNodeBs and transport equipment.
Balances load on Ethernet links between the eNodeB and transport equipment and increases the link bandwidth.
Description Ethernet link aggregation is a protocol defined in IEEE 802.3ad. IEEE 802.3ad defines the link aggregation control protocol (LACP) used to detect link status in a link group. The eNodeB supports static LACP, with parameters of a link group configured manually. Fault detecting also uses the LACP. Figure 4-13 illustrates Ethernet link aggregation. Figure 4-13 Ethernet link aggregation
Enhancement None
Dependency This feature does not apply to micro eNodeBs. The transport equipment directly connected to eNodeBs must support this feature. Ethernet interfaces are used.
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4.4 RAN Sharing 4.4.1 TDLOFD-001036 RAN Sharing with Common Carrier Availability This feature was introduced in LTE TDD eRAN2.2.
Summary eNodeBs support multiple operators sharing the same RAN, where the operators use common carriers on the same eNodeB.
Benefits Operators can share RAN resources to reduce CAPEX and OPEX.
Description In the multioperator core network (MOCN) sharing solution, RAN resources are shared, including frequency and baseband resources, for all operators. Different operators share the same cell and each eNodeB can connect to the core networks of all operators. The system information broadcast in each shared cell contains the PLMN ID of each operator (up to four) and a single TA code valid within all of the PLMNs sharing RAN resources. All LTE UEs supporting MOCN can read a maximum of four PLMN IDs and select one at initial attachment. UEs send the selected PLMN ID to the eNodeB. The eNodeB selects an appropriate MME for a UE. The MOCN network sharing solution supports the shared master OSS, which connects to different network management systems (NMSs) through different interfaces. The shared eNodeB and non-shared eNodeB can be connected to each other. In the shared area, a UE can be handed over from one shared eNodeB to another. If the UE moves to a non-shared area, the eNodeB selects an appropriate neighbor cell for the handover based on certain principles (for example, the same operator's network may be preferentially considered). Interworking between different RATs may be used during the handover. In RAN sharing with common carrier mode, the following functions are available:
Multiple PLMN IDs are broadcast on the common carrier and the core network is separately deployed.
The logo and name of an operator can be displayed on UEs.
The shared OSS connects to different NMSs through Itf-N interferences.
A maximum of four operators can share RAN resources.
Dynamic radio resource management was introduced. This feature guarantees the fairness and flexibility of MOCN network sharing in both the uplink and downlink. All radio resources can be shard dynamically and fairly between MOCN operators. Any remaining resources can be used by other operators. In addition, this feature balances the maximum system between MOCN operators. Operators sharing a network may have different service and price models. The QoS parameters may be completely different. Issue 02 (2016-07-30)
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Without this feature, in high load situations, the operator with higher QoS services will occupy more radio resources because the dynamic scheduling algorithm considers the QCI to balance system throughput and user fairness. With this feature, operator fairness is considered. The priority of each operator is calculated according to the ratio of occupied RBs and the predefined ratio of each operator. Resources are scheduled between the operators based on operator priorities, and then the resources for one operator are scheduled within this operator. The pre-emption algorithm in admission control is also enhanced in this feature. The service provided by operator A can pre-empt the resources of the service provided by operator B only when both of the following conditions are met: The ratio of RBs occupied for the service provided by operator A is less than the predefined ratio of operator A. The ratio of RBs occupied for the service provided by operator B is greater than the predefined ratio of operator B. In eRAN3.0, multiple operators can share the MME and S1 link.
Enhancement None
Dependency If the MOCN or gateway core network (GWCN) is used, this feature requires TDLOFD-001018 S1-flex. This feature does not work when the eNodeB bandwidth is 5 MHz.
4.4.2 TDLOFD-001037 RAN Sharing with Dedicated Carrier Availability This feature was introduced in LTE TDD eRAN2.2.
Summary eNodeBs support multiple operators sharing the same RAN, where the operators use dedicated carriers on the same eNodeB.
Benefits Operators can share RAN resources to reduce CAPEX and OPEX.
Description Huawei eNodeBs support RAN sharing as a part of network sharing functions. This feature allows multiple operators to share all eNodeB hardware resources. Different core networks are separately connected to the same eNodeB. Multiple operators can cover the same area by using their own frequencies in a single physical RAN. A TA must include multiple shared cells.
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Figure 4-14 illustrates the architecture in RAN sharing with dedicated carrier mode. Figure 4-14 Architecture in RAN sharing with dedicated carrier mode
When a UE accesses a cell, the eNodeB selects the core network to which the UE must be routed according to the original serving cell. If S1-flex is applied, the eNodeB may select an MME node for the UE based on the globally unique MME identifier (GUMMEI), which is part of the globally unique temporary identity (GUTI) of the UE. The network sharing solution supports the shared master OSS, which connects to different NMSs through different interfaces. Cell-level FM and PM data can be independent for all operators. The shared eNodeB and non-shared eNodeB can be connected to each other and a UE can be handed over from a shared eNodeB to a non-shared eNodeB. When operators have dedicated networks in the non-shared area, the UE can only be handed over to the same operator's network. The target network of the same operator may not be an LTE network. In RAN sharing with dedicated carrier mode, the following functions are available:
Each operator broadcasts its own PLMN ID separately using its own carrier and within its own core network.
The logo and name of an operator can be displayed on UEs.
Cell-level FM and PM data can be independent for all operators. The shared OSS connects to different NMSs through Itf-N interferences.
License management and feature activation and deactivation are performed independently for operators.
Enhancement None
Dependency If the MOCN or GWCN is used, this feature requires TDLOFD-001018 S1-flex. This feature does not work when the eNodeB bandwidth is 5 MHz.
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4.4.3 TDLOFD-081224 Hybrid RAN Sharing Availability This feature is:
Available in macro eNodeBs and LampSite eNodeBs as of LTE TDD eRAN8.1.
Not available in micro eNodeBs.
Summary The flourishing of LTE networks calls for more diversity in RAN sharing. Additionally, RAN sharing with common carriers and RAN sharing with dedicated carriers have their own restrictions. For example, RAN sharing with common carriers requires that the cells under a shared eNodeB must have the same primary PLMN ID, and RAN sharing with dedicated carriers disallows multiple operators to share a cell. The Hybrid RAN Sharing feature eliminates such restrictions by allowing multiple operators to share a cell and allowing shared cells to have different primary PLMN IDs.
Benefits Hybrid RAN Sharing curtails the capital expenditure (CAPEX) and operating expense (OPEX) of operators by allowing flexible RAN sharing and accelerates the pace of network deployment.
Description Hybrid RAN Sharing allows operators to share RAN resources when all the following conditions are met:
Each eNodeB operates on two or more frequencies.
At least one frequency is shared by operators.
Two or more cells have different primary PLMN IDs.
The following are two typical application scenarios of Hybrid RAN Sharing:
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A shared eNodeB operates on both common and dedicated frequencies. For example, operators A and B share frequency 1 (A being the primary operator), and operator B uses a dedicated frequency (frequency 2), as shown in Figure 4-15.
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Figure 4-15 Shared eNodeB operating on both common and dedicated frequencies
Operators share different operating frequencies of an eNodeB. For example, operators A and B share frequency 1 (A being the primary operator), and operators C and D share frequency 2 (C being the primary operator), as shown in Figure 4-16 . Figure 4-16 Operators sharing different frequencies
In Hybrid RAN Sharing scenarios, the eNodeB can be shared by up to four operators and configured primary and secondary operator information for each cell. The procedure of user's PLMN ID selection is as below: 1.
eNodeB broadcast the primary and secondary PLMN ID in system information.
2.
UE get the PLMN ID list in SIB1 of shared cell and select one proper PLMN as its serving PLMN
3.
eNodeB establish the connection to particular MME for a UE according to the PLMN ID that UE selected.
In Hybrid RAN Sharing scenarios, related features, resources and OSS management follow the policies below:
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The feature configuration of a shared cell must keep same between different operators, which is same as MOCN cell.
The allocation of cell-specific resources for a shared cell, such PRB resource, are same as MOCN cell. The eNodeB-specific resources, such as RRC connected user number, are shared by multiple operators.
OSS is shared by multiple operators and connected to NMSs of different operators by different Itf-N interface. The information such as configuration management, fault management and performance management can be reported individually to different NMS.
Hybrid RAN Sharing is compatible with RAN sharing with common carriers and RAN sharing with dedicated carriers. Purchasing the license for Hybrid RAN Sharing eliminates the need to purchase licenses for RAN sharing with common carriers and RAN sharing with dedicated carriers.
Enhancement None
Dependency
Other features If a shared eNodeB is connected to multiple non-shared MMEs, TDLOFD-081224 Hybrid RAN Sharing is dependent on TDLOFD-001018 S1-flex. If a shared eNodeB is connected to a shared MME, TDLOFD-081224 Hybrid RAN Sharing is not dependent on any feature.
4.4.4 TDLOFD-001086 RAN Sharing by More Operators Availability This feature was introduced in LTE TDD eRAN6.0.
Summary A maximum of six operators can share an eNodeB in RAN sharing mode.
Benefits More operators can share an eNodeB, greatly reducing operator CAPEX and OPEX.
Description eNodeBs support two RAN sharing modes: RAN sharing with common carrier and RAN sharing with dedicated carrier. In either mode, a maximum of six operators can share an eNodeB and manage the eNodeB on the element management system (EMS). The EMS is connected to the NMSs of the operators through northbound interfaces. In RAN sharing with dedicated carrier mode, operators can share only eNodeB hardware. In RAN sharing with common carriers mode, operators can share both eNodeB hardware and the cells served by the eNodeB. In RAN sharing with common carrier mode, the following functions are available:
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A shared eNodeB broadcasts system information block type 1 (SIB1) in each shared cell. Each SIB1 contains a PLMN ID list and a common TA code. A PLMN ID list can contain a maximum of six PLMN IDs.
The logo and name of an operator can be displayed on UEs.
A shared eNodeB can dynamically allocate radio resources to operators to ensure flexible and fair resource scheduling.
Dynamic allocation is based on the following mechanisms:#li17489764
Admission control based on the satisfaction of each type of service provided by the operators
Operator-specific load control
Fair resource scheduling between the operators
Resource allocation ratio configured for each operator To improve resource usage, the resources that are allocated to but not used by an operator can be shared by other operators.
UEs can use the resources allocated by shared and non-shared eNodeBs.
A shared eNodeB can be connected to other shared eNodeBs and non-shared eNodeBs. When a UE is moving between shared eNodeBs or between a shared eNodeB and a non-shared eNodeB, the operator serving the UE remains unchanged.
Enhancement None
Dependency This feature requires either of the following features:
TDLOFD-001036 RAN Sharing with Common Carrier
TDLOFD-001037 RAN Sharing with Dedicated Carrier
4.4.5 TDLOFD-001112 MOCN Flexible Priority Based Camping Availability This feature was introduced in LTE TDD eRAN6.0.
Summary In RAN sharing with common carriers mode, absolute cell-reselection priorities of frequencies are broadcast in system information without distinguishing between operators. With this feature, operator-specific cell-reselection priorities can be specified for intra- or inter-RAT neighboring frequencies.
Benefits This feature helps operators implement their customized camping policies for UEs in idle mode.
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Description The cell-reselection priority of an intra- or inter-RAT neighboring frequency can be set for different operators identified by PLMN IDs. If an operator-specific cell-reselection priority is set, the priority is used as a dedicated priority of the frequency. If dedicated priorities are set, the eNodeB filters frequencies based on the serving PLMN of the UE and delivers the corresponding priority to the UE in the IE IdleModeMobilityControlInfo in the RRC Connection Release message.
Enhancement None
Dependency This feature requires TDLOFD-001036 RAN Sharing with Common Carrier.
4.4.6 TDLOFD-001133 Multi Operators SPID Policy Availability This feature was introduced in LTE TDD eRAN6.0.
Summary eNodeBs support operator-specific subscriber profile ID for RAT/frequency priority (SPID) policies so that UEs camp on different networks based on their cell reselection priorities.
Benefits In RAN sharing scenarios, this feature allows operators to customize RRM policies, such as the camping policies of UEs in idle mode. Operators can configure the same SPID range.
Description An operator registers an SPID (a policy index ranging from 0 to 255) for UEs in a home subscriber server (HSS) database. Based on the SPID, an eNodeB then performs service processing dedicated to the UEs. SPID policies can be customized for different operators on an eNodeB. Based on the serving PLMNs and SPIDs of UEs, operators share the eNodeB, query eNodeB local configurations, and enable the eNodeB to deliver the customized cell reselection policies to UEs. This feature supports the cell reselection policies that are customized based only on SPIDs. Different operators can register the same SPID for a UE and can also customize different cell reselection policies on shared eNodeBs.
Enhancement None
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Dependency This feature requires the following features:
TDLBFD-00201803 Cell Selection and Re-selection
TDLOFD-001054 Flexible User Steering
4.5 Advance Micro 4.5.1 TDLOFD-001057 Load Balancing based on Transport QoS Availability This feature was introduced in LTE TDD eRAN6.1.
Summary The transport capability of a micro eNodeB is weaker than that of a macro eNodeB. When the service load on the micro eNodeB is high and the backhaul traffic is heavy, the transport capability over the S1 interface may be insufficient. In this case, the micro eNodeB uses the load balancing algorithm to hand over some of the UEs to the cells under other micro or macro eNodeBs.
Benefits This feature balances the transport load over an S1 interface to prevent congestion.
Description This feature applies when the transport load over an S1 interface is heavy on a micro eNodeB but is light on other eNodeBs due to different services and UEs. The micro eNodeB measures the transport load over the S1 interface and at the same time receives the load information of neighboring eNodeBs. Based on the measurement results and received information, the micro eNodeB determines the transport load status. If the S1 interface transport load on the micro eNodeB exceeds the threshold and the S1 interface transport load on the neighboring eNodeBs is light, the micro eNodeB hands over some UEs to the cells under the neighboring eNodeBs. The transport load over the S1 interface is the transmission bandwidth utilization. Only inter-frequency load balancing is supported. This feature is used when inter-frequency cells have overlapping coverage.
Enhancement None
Dependency The X2 interface must be configured.
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This feature requires the following functions and feature:
Load control function for obtaining the load information of neighboring cells
Mobility management function for implementing handovers
TDLOFD-001032 Intra-LTE Load Balancing
This feature only applies to micro eNodeBs.
4.5.2 TDLOFD-003022 PPPoE Availability This feature was introduced in LTE TDD eRAN6.1.
Summary PPPoE is a network communication protocol for the data link layer and is used to encapsulate Point-to-Point Protocol (PPP) frames into Ethernet frames. An eNodeB enabled with PPPoE supports PPPoE authentication when the eNodeB accesses the EPC through a public network (xPON or xDSL).
Benefits With PPPoE, eNodeBs access and use operators' broadband networks as backhaul networks, thereby saving the deployment cost of the backhaul networks.
Description Ethernet networks are based on frames without security protection against IP and MAC addresses, and DHCP servers. By using PPPoE, users can virtually dial from one device to another over an Ethernet network, establish a point-to-point connection, and then securely transmit data packets. PPPoE can be integrated with the current dial-up AAA system where it fits perfectly into the current ATM backbone networks. Compared with DHCP, PPPoE allows pre-paid traffic bucket business models to obtain static IP addresses and guarantee QoS requirements more easily.
Enhancement None
Dependency This feature only applies to micro eNodeBs.
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5
O&M
5.1 SON 5.1.1 TDLOFD-002001 Automatic Neighbour Relation (ANR) Availability This feature is available as of LTE TDD eRAN1.0.
Summary When this feature is enabled, the eNodeB uses algorithms to automatically plan and configure neighbor relationships, resolving issues with incorrect neighbor relationship configuration.
Benefits This feature provides the following benefits:
Manual configuration is not required, reducing workload and OPEX.
Missing or incorrect neighbor relationships can be identified or optimized, eliminating handover failures caused by missing or incorrect neighbor relationship configuration.
Physical cell identifier (PCI) conflict detection can be triggered.
Description ANR can automatically add and update neighbor relationships in the neighboring relation table (NRT). However, the manual configuration of NRT attributes, including No HO and No Remove, have higher priority than the ANR algorithm. For example, if an operator sets the No Remove attribute to true, ANR will not remove this record from the NRT. Figure 5-1 shows the ANR procedure.
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Figure 5-1 ANR procedure
The ANR process consists of the following steps: 1.
The source eNodeB informs the UE which E-UTRA frequency needs to be measured.
2.
The UE returns a measurement report regarding cell B. This report contains cell B's PCI but does not include its global cell identity (GCI). When the eNodeB receives a UE measurement report containing the PCI that is not included in the NRT for that cell, the following sequence may be used.
3.
The eNodeB instructs the UE to use the newly discovered PCI as the parameter to read the GCI of the related neighboring cell. The eNodeB may schedule appropriate intervals for the UE to read the GCI of the neighboring cell because the UE must decode the broadcasted GCI of the new cell.
4.
After the UE reads the GCI of the new cell, it reports the detected GCI to the serving eNodeB.
5.
The eNodeB determines that this neighbor relationship should be added and uses the PCI and GCI to perform the following operations: −
Searches for a transport layer address to the new eNodeB. (OM or MME search mechanisms have already been standardized by the 3GPP.)
−
Updates its NRT.
The eNodeB or serving cell finds a new neighboring cell by using one of the following methods:
The PCI of the neighboring cell is reported to the eNodeB in the UE measurement report. Then, the eNodeB instructs the UE to read the GCI of the new neighboring cell.
The GCI of the neighboring cell is sent to the eNodeB in the UE history information of the HANDOVER REQUEST, and then the eNodeB requests the PCI of the new neighboring cell.
After the eNodeB adds the new neighboring cell, the PCI conflict detection procedure can be activated. For details on PCI conflict detection, see TDLOFD-002007 PCI Collision Detection & Self-Optimization. If required, an X2 interface establishment can also be activated through the automatic transport setup function in TDLOFD-002004 Self-configuration. Periodic ANR is supported. Measurements are periodically performed to select and configure UEs to report the strongest LTE cells. If a UE reports an unknown PCI, the eNodeB triggers an ANR measurement to determine the corresponding GCI. Periodic ANR improves handover performance.
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Enhancement In LTE TDD eRAN2.1, the ANR feature is enhanced with the log function. Logs record key events during the SON process. Operators can use the log information to perform queries, collect statistics, and analyze the feature running process and key events. In LTE TDD eRAN6.1, eNodeBs support automatic setting of the NO HO attribute. ANR can automatically identify the neighboring cells with a low handover success rate, and set NoHoFlag to FORBID_HO_ENUM(Forbid Ho) to prohibit handovers to them. This function reduces handover failures and thereby increases the handover success rate. In LTE TDD eRAN8.1, this feature is enhanced with the following functions:
Detection of neighboring cells for PCI confusion based on the handover success rate The function of automatic optimization of the No HO attribute has been enhanced. The eNodeB automatically instructs a UE to re-read the ECGI of a neighboring cell to which the success rate of handovers from the local cell is low. After the UE reads the ECGI, if the handover success rate keeps low, the eNodeB automatically sets the NoHoFlag parameter to FORBID_HO_ENUM(Forbid Ho) for this neighboring cell. This prevents such a neighboring cell from affecting the handover success rate of the overall network.
Enhanced X2 automatic removal
eNodeBs support automatic removal of faulty X2 interfaces and X2 interfaces with low usage.
In LTE TDD eRAN11.1, eNodeBs support overshooting neighboring cell restriction. An overshooting neighboring cell provides cell coverage larger than expected, which is determined in terms of the topology based on longitudes and latitudes and cell radii of the serving and neighboring cells. In the live network, ANR adds a lot of overshooting neighboring cells because of RF planning and unstable neighboring cell signals detected by UEs. This affects network maintenance and handover performance. If overshooting neighboring cells are added to the NRTs, KPIs may deteriorate. Overshooting neighboring cell restriction can detect overshooting neighboring cells and manage them individually, avoiding them from being added to the NRTs. E-UTRAN overshooting neighboring cell restriction can detect intra-RAT overshooting neighboring cells.
Dependency This feature requires the OSS feature WOFD-180600 Automatic Neighbor Relation Optimization - LTE. UEs must support ANR and DRX.
5.1.2 TDLOFD-002002 Inter-RAT ANR Availability This feature is available as of LTE TDD eRAN3.0.
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Summary Inter-RAT ANR takes advantage of the eNodeB algorithm to plan, configure neighbor relationships, and resolve issues of incorrect neighbor relationships of E-UTRAN cells with GERAN or UTRAN cells.
Benefits In an LTE system, inter-RAT neighbor relationships can be automatically added without manual intervention, reducing operator OPEX.
Description Inter-RAT ANR can automatically add neighbor relationships in the eNodeB based on inter-RAT measurement results reported from UEs. Inter-RAT coverage is broadcast in the E-UTRAN. Then, UEs can measure and report the inter-RAT cells to the eNodeB and instruct it to build up inter-RAT neighbor relationships for further inter-RAT mobility. This feature includes the following functions:
Measure UTRAN and GERAN cells
Add the neighbor relationships of E-UTRAN with inter-RAT cells to the eNodeB.
Configure the constraints between the E-UTRAN and inter-RAT cells (for example, operator-specific mobility limitation policy)
The following figure shows the inter-RAT ANR procedure. Figure 5-2 Inter-RAT ANR procedure
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It is assumed that inter-RAT ANR is executed by using the U2000 client, which can manage the followings:
Inter-RAT/frequency search list: A list of RATs or frequencies that must be searched.
Inter-RAT/frequency ANR blacklist: A list of cells that cannot be included in the eNodeB inter-RAT/frequency neighboring cell lists.
It is also assumed that the OM system is informed about changes in the eNodeB inter-RAT/frequency neighboring cell lists. The serving cell A has been enabled with the ANR function. During a normal call procedure, the eNodeB instructs each UE to perform measurements and search inter-RAT/frequency cells. The eNodeB may use different policies for instructing the UE to perform and report measurements. 1.
The eNodeB instructs the UE to search neighboring cells in the target RATs/frequencies. The eNodeB may schedule appropriate gaps so that the UE can scan all cells in the target RATs/frequencies.
2.
The UE reports the PCI of the detected cells in the target RATs/frequencies along with their respective signal quality. The carrier frequency and primary scrambling code (PSC) define the PCI of the detected cell if a UTRAN cell is detected. The band Indicator, BSIC, and BCCH ARFCN define the PCI of the detected cell if a GERAN cell is detected. The eNodeB instructs the UE to use the newly detected Phy-CID as a parameter and to read the Global-CID of the detected neighboring cell in the target RAT/frequency.
3.
The eNodeB may schedule appropriate gaps for the UE to read the Global-CID from the broadcast channel of the detected neighboring cell.
4.
After reading the Global-CID of the new cell, the UE reports the detected Global-CID to the serving eNodeB. The eNodeB updates its inter-RAT/frequency neighboring cell lists.
Periodic inter-RAT ANR is supported. Measurements are periodically performed to select and configure UEs to report the strongest LTE cells or report the strongest cells for inter-RAT SON. If a UE reports an unknown layer-1 cell identity (PCI, PSC, and BSIC), the eNodeB triggers an inter-RAT ANR measurement to identify the corresponding GCI. Periodic inter-RAT ANR improves handover performance.
Enhancement In LTE TDD eRAN8.0, optimize the neighborhood selection function between UTRAN and LTE TDD system.
Handover: Acquire neighborhood priority according the number of measured times
Redirection: Sequencing neighborhood according the priority selection
In LTE TDD eRAN11.1, eNodeBs support overshooting neighboring cell restriction. An overshooting neighboring cell provides cell coverage larger than expected, which is determined in terms of the topology based on longitudes and latitudes and cell radii of the serving and neighboring cells. In the live network, ANR adds a lot of overshooting neighboring cells because of RF planning and unstable neighboring cell signals detected by UEs. This affects network maintenance and handover performance. If overshooting neighboring cells are added to the NRTs, KPIs may deteriorate. Overshooting neighboring cell restriction can detect overshooting neighboring
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cells and manage them individually, avoiding them from being added to the NRTs. UTRAN overshooting neighboring cell restriction can detect overshooting UTRAN neighboring cells.
Dependency This feature requires the OSS feature WOFD-181400 Inter-RAT Automatic Neighbor Relation Optimization-LTE. UEs must support ANR and DRX.
5.1.3 TDLOFD-002004 Self-configuration Availability This feature is available as of LTE TDD eRAN1.0.
Summary This feature enables an eNodeB to automatically establish an operation and maintenance (O&M) link, obtain the configuration data file and software from the element management system (EMS), and then activate the configuration data file and software. The configuration data file contains radio parameters and transport parameters. After that, the eNodeB performs a self-test and reports the test result to the EMS. After the configuration data file and software are downloaded, the U2000 or LMT automatically starts a comprehensive self-test procedure on the eNodeB. After the test is complete, the U2000 or LMT can obtain a test report.
Benefits Only hardware installation needs to be performed by field engineers for initial eNodeB startup.
Description When the eNodeB is powered on, it obtains the required data to establish an O&M link, such as the O&M IP address of the eNodeB, subnet mask, IP address of the EMS, and IP address of the security gateway (SeGW), through the Dynamic Host Configuration Protocol (DHCP) server. After the O&M link is established, the eNodeB automatically downloads and activates the configuration data file and software according to the instruction from the EMS. Then, the eNodeB performs a self-test to ensure that it is ready to provide services and reports the test result to the EMS. After the configuration data file and software are downloaded, the U2000 or LMT automatically starts a comprehensive self-test procedure on the eNodeB. After the test is complete, the U2000 or LMT obtains a test report, indicating the eNodeB status. The test report contains the following information:
eNodeB basic information, such as the type, name, mobile network code (MNC), mobile country code (MCC), and electrical serial number
Software version information
Board status information, such as information about the baseband processing units and RRUs
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Transport status information (physical layer and data link layer)
Clock status
Cell status
Ambient temperature and relative humidity
Enhancement In LTE TDD eRAN1.0, the eNodeB can automatically establish an IPsec link with the SeGW during self-configuration. In LTE TDD eRAN1.0, if the eNodeB is equipped with a GPS device, it can obtain geographical information from the GPS device and report it to the EMS. The EMS will automatically identify the eNodeB by comparing the received geographical information with the predefined geographical information. In LTE TDD eRAN1.0, automatic transport setup is supported. The eNodeB has three types of transport-related interfaces: S1 interface, X2 interface, and O&M channel interface. Accordingly, the eNodeB provides three automatic transport setup processes: S1 self-setup, X2 self-setup, and O&M channel self-setup. Figure 5-3 illustrates the general network topology. Figure 5-3 General network topology
RAN Network Element Manager: RAN network element management platform
The eNodeB parameters (such as the MAC address, local O&M IP address, unique ID, and security key) have been pre-configured in the factory or other places and therefore do not need to be manually configured or modified. The automatic transport setup procedure is as follows:
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When the eNodeB is powered on, it automatically negotiates with the peer device about Layer-1 or 2 (physical or MAC layer) parameters, such as duplex mode. The peer device can be a LAN switch, router, or another eNodeB.
The eNodeB receives O&M channel parameters from the DHCP server, for example, the Internet IP address, network element manager (NEM) IP address, and SeGW IP address.
The eNodeB establishes an IPsec tunnel with the SeGW, obtains the internal IP address, and then establishes the O&M channel with the NEM.
After the configuration data file and software are downloaded and activated, the eNodeB receives the necessary S1 interface transmission parameters from the NEM, such as the eNodeB service IP address and MME SCTP link IP address.
The eNodeB starts the S1 self-setup procedure and establishes the S1 interface.
X2 interface self-setup based on automatic neighbor relation (ANR) is supported. An eNodeB can identify a new eNodeB with which the neighbor relationship is not configured. After receiving necessary transport data from the NEM, the eNodeB automatically establishes the X2 interface with this new neighboring eNodeB. In LTE TDD eRAN11.0, the eNodeB can obtain the MME IP address from the domain name server (DNS) and complete S1-C link self-configuration, simplifying eNodeB operations in MME deployment and relocation scenarios and improving O&M efficiency.
Dependency The X2 self-setup function in this feature requires ANR.
5.1.4 TDLOFD-002007 PCI Collision Detection & Self-Optimization Availability This feature is available in LTE TDD eRAN2.1.
Summary This feature detects PCI conflicts using ANR and performs self-optimization in the EMS to resolve these conflicts.
Benefits This feature reduces OPEX.
Description PCI is a physical cell identifier or layer-1 identifier. It is an essential configuration parameter to E-UTRAN cells. It corresponds to a unique combination of one orthogonal sequence and one pseudo-random sequence. In the LTE system, there are only 504 PCIs that can be repeatedly used. The two cells that share a PCI cannot be geographically close to each other. Otherwise, they will interfere with each other. PCIs are used to transmit data in a cell. When a new eNodeB is delivered to the site, a PCI must be selected for each cell of the eNodeB. This selection avoids PCI conflicts between a serving cell and its neighboring cells. PCI conflicts cause interference, and therefore affect services. The PCI assignment must meet the following conditions: Issue 02 (2016-07-30)
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Collision-free: The PCI is unique in the coverage area of a cell.
Confusion-free: A cell must not have neighboring cells with an identical PCI.
Whenever the new neighbor relationship is added by the eNodeB, the PCI conflict detection procedure is triggered to check the possible PCI conflicts within the neighboring cells.
Enhancement In LTE TDD eRAN2.1, PCI conflict detection is enhanced with self-optimization implemented in the EMS to resolve the detected conflicts. In order to allocate the optimal candidate PCI for the entire network, and to minimize the interference among neighboring cells, the site engineering information(longitude, latitude, and azimuth), CGI, and neighbor cell list are taken into the PCI assignment. The new assigned PCI can be configured in three manners:
Immediate and automatic delivery: The EMS delivers new PCIs to the eNodeB immediately after they are generated.
Scheduled and automatic delivery: The EMS periodically delivers new PCIs.
Manual delivery: The EMS generates a notice for confirmation before delivering new PCIs to the eNodeB.
This feature is enhanced with specific management functions, such as feature settings (enabling/disabling this feature or its functions, parameter settings, and policy settings), evaluation (validity, network impact, and expected operation notification), and logging (key event logging). Therefore, operators can monitor and control feature configuration, modification, and execution when obtaining the expected result. The management functions are described as follows:
Settings Settings include the following operations:
−
Enabling and disabling: Users can enable or disable this feature.
−
Parameter settings: Operators can set some parameters about this feature.
−
Breakpoint: Operators can set up breakpoints to enhance the feature control capability. The algorithm can be stopped at the breakpoints and operator confirmation is needed for process continuity.
Evaluation It consists of performance evaluation and simulation preview. Using these methods, performance evaluation enables operators to control the quality, effectiveness, and feature impact on the network.
Logging
This function records key events during the SON process and these events can be used for query and statistics. Operators can also analyze the log information to learn about the feature running process and key events. In LTE TDD eRAN8.1, the eNodeB incorporates the following function:
Optimization of PCI collision detection and PCI confusion detection PCI collision detection and PCI confusion detection are independently controlled. When RRUs are configured, it is recommended that only PCI confusion detection be enabled to prevent incorrect PCI collision detection.
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Dependency This feature requires WOFD-170200 Automatic PCI Optimization -LTE FDD/TDD.
5.1.5 TDLOFD-110231 Auto Neighbor Group Configuration Availability This feature is:
Available in macro eNodeBs as of LTE TDD eRAN11.0.
Available in micro eNodeBs as of LTE TDD eRAN11.0.
Available in LampSite eNodeBs as of LTE TDD eRAN11.0.
Summary This feature consists of the following functions:
CA automatic neighbor group configuration This function automatically configures SCell blind configuration flags.
MLB automatic neighbor group configuration This function automatically configures overlapping indicators for inter-frequency neighboring cells.
The two functions are independent of each other and can be used separately.
Benefits After this feature is enabled, SCell blind configuration flags and overlapping indicators do not need to be manually configured, reducing O&M costs.
Description
CA automatic neighbor group configuration The SCell blind configuration flag is a CA parameter. A candidate SCell configured with this parameter can perform blind configuration without measurement. When this function is not used, users must manually identify cell coverage overlapping relationships before adding, modifying, or removing SCell blind configuration flags. Such operations have high requirements on accuracy and are time-consuming. Based on measurement event statistics and the configurable threshold on the network, this function automatically identifies inter-frequency neighboring cells whose SCell blind configuration flags need to be added, modified, or removed. Then, this function adds, modifies, or removes these flags automatically (or in a controlled way), thereby reducing manual workload.
MLB automatic neighbor group configuration The overlapping indicator is an MLB parameter. This parameter is used for accurate candidate cell selection in MLB. When this function is not used, users must manually identify cell coverage overlapping relationships before adding, modifying, or removing overlapping indicators. Such operations have high requirements on accuracy and are time-consuming.
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Based on measurement event statistics and the configurable threshold on the network, this function automatically identifies inter-frequency neighboring cells whose overlapping indicators need to be added, modified, or removed. Then, this function adds, modifies, or removes these indicators automatically (or in a controlled way), thereby reducing manual workload.
Enhancement In eRAN11.1, automatic configuration of overlapping indicators is enhanced by adding the following subfunctions:
Automatic configuration of an overlapping indicator for a micro cell If a micro cell detects that its coverage range is within that of a macro cell, the micro cell can proactively notify the macro cell to configure an overlapping indicator.
Automatic configuration of overlapping indicators for a micro cell group If the coverage ranges of multiple micro cells are within the coverage range of a macro cell, the macro cell can regard multiple micro cells using the same EARFCN as one micro cell group. If an overlapping indicator needs to be added to the micro cell group, the macro cell adds the overlapping indicator to each micro cell in the micro cell group. If the overlapping indicator needs to be removed from the micro cell group, the macro cell removes the overlapping indicator from each micro cell in the group.
Dependency
eNodeB None
UE None
Transport network None
Core network None
OSS None
Other features None
Others The corresponding neighboring cells must use Huawei devices.
5.1.6 TDLOFD-002005 Mobility Robust Optimization (MRO) Availability This feature is available in LTE TDD eRAN3.0.
Summary MRO aims to reduce ping-pong handovers, premature handovers, and delayed handovers. It is implemented by optimizing the typical mobility control parameters.
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Benefits This feature provides the following benefits:
Decreases the call drop rate, reduces the handover failure rate, and speeds up cell reselection.
Saves man power cost for typical and common mobility optimization scenarios.
Description MRO typically adjusts the cell individual offset (CIO). CIO is adjusted online. CIO explicitly declares the handover threshold between measurement results of signaling quality from both source and target cells. Therefore, changing the CIO will shift ahead or delay the happening of handovers. The major MRO parameter adjustment is the CIO. Both premature and delayed handovers are captured at the source eNodeB because the source eNodeB is informed of delayed handovers that have been prepared by the UE context release mechanism. Only outgoing handover failures are captured. The reduction of ping-pong handovers exploits the UE History Information that is passed from the source eNodeB to the target eNodeB during the handover preparation. When the UE History Information is received, the target eNodeB identifies ping-pong if the second newest cell's GCI is equal to that of the target cell and the time spent in the source cell is less than a ping-pong time threshold. Ping-pong handovers are rectified by decreasing the CIO.
Enhancement
In LTE TDD eRAN6.0 UE-level MRO against ping-pong handovers is introduced. The eNodeB identifies ping-pong UEs and sends corresponding UE-level MRO parameters to these UEs. This type of MRO reduces the number of ping-pong handovers, reduces Uu resource usage, and improves quality of experience (QoE) of UEs. The UE-level MRO algorithm is independent of the cell-level MRO algorithm. They are controlled by different switches.
In LTE TDD eRAN6.1 a.
The controllable intra-RAT MRO function is introduced. Intra-RAT MRO (including intra-frequency MRO and inter-frequency MRO) can be implemented in free and controlled modes. In free mode, the intra-RAT MRO procedure is the same as that in eRAN6.0, that is, the eNodeB automatically optimizes parameters according to parameter optimization suggestions. In controlled mode, the eNodeB reports parameter optimization suggestions to the U2000. The U2000 optimizes parameters after the parameter optimization suggestions are manually confirmed. During the confirmation, users can change the suggested parameter values on the U2000.
b.
The cell reselection parameter optimization for intra-frequency MRO is introduced. During intra-frequency MRO, the eNodeB checks whether cell reselection conditions match handover conditions. If they do not match, the eNodeB optimizes cell reselection parameters. Cell reselection parameter optimization for intra-frequency MRO can be implemented in free and controlled modes.
In LTE TDD eRAN7.0 a.
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If performance counters deteriorate an MRO period after intra-RAT MRO is performed, parameter setting rollback is implemented. b.
The threshold setting in different intra-RAT MRO scenarios is introduced. During intra-RAT MRO, users can set different thresholds for different scenarios, including the thresholds for the proportions of premature handovers, delayed handovers, and RLF-induced abnormal handovers.
In LTE TDD eRAN8.0 a.
The mechanism for changing the event A1 triggering threshold when the event A2 triggering threshold is optimized by inter-frequency MRO is introduced. The event A1 triggering threshold is changed when the event A2 triggering threshold is optimized to ensure that the difference between the two thresholds is constant. The adjustment range of the event A2 triggering threshold is determined by the user-specified range.
b.
The adjustments of parameters for events A2 and A3/A4 during inter-frequency MRO are controlled by switches.
A parameter adjustment option is added to allow users to configure parameters for event A2, A3/A4, or A2+A3/A4 to be adjusted. MRO optimizes parameters based on parameter adjustment configurations.
In LTE TDD eRAN8.1 The MRO against unnecessary handovers function is introduced. The measurement of unnecessary handovers is added. MRO is implemented in the cells where the proportion of unnecessary handovers is high so that UEs camp on LTE cells in any possible conditions.
Dependency None
5.1.7 TDLOFD-081201 Specified PCI Group-based Neighboring Cell Management Availability This feature is:
Available in macro eNodeBs eNodeBs as of LTE TDD eRAN8.1.
Available in LampSite eNodeBs as of LTE TDD eRAN8.1.
Available in micro eNodeBs as of LTE TDD eRAN11.0.
Summary In scenarios where a large number of micro eNodeBs are deployed around a macro eNodeB, cells served by micro and macro eNodeBs are assigned with physical cell identifiers (PCIs) in different ranges. eNodeBs deploy different management policies on neighboring cells within different PCI ranges and perform handovers from a macro eNodeB to a micro eNodeB based on the cell global identification (CGI) reading results.
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Benefits
Simplifies PCI planning for scenarios where a large number of micro eNodeBs are deployed.
Supports handovers from a macro eNodeB to a micro eNodeB and prevents handover failures caused by PCI reuse among micro eNodeBs.
Reduces the operating expense (OPEX), and ensures handovers from a macro eNodeB to a micro eNodeB.
Description In scenarios where a large number of micro eNodeBs are deployed around a macro eNodeB, cells served by micro and macro eNodeBs are assigned with physical cell identifiers (PCIs) in different ranges. The PCIs are classified into PCIs for cells served by normal eNodeBs (referred to as PCI range A) and PCIs for cells served by densely deployed eNodeBs (referred to as PCI range B). To make this feature work, operators need to allocate PCIs in range A and range B for cells served by macro eNodeBs and micro eNodeBs, respectively. After an eNodeB receives a measurement report from a UE, the eNodeB checks the type of neighboring cells contained in the measurement report based on the PCIs. If the serving cell is served by a macro eNodeB and the detected neighboring cell is served by a micro eNodeB, the serving eNodeB instructs the UE to read the CGI of the neighboring cell regardless whether the neighboring relationship with the detected cell of the serving cell is configured. Then, the serving eNodeB adds or updates the neighbor relationship based on the CGI reading results and determines the target cell for the handover. In the preceding scenario, it is allowed that intra-frequency neighboring cells that have the same PCI and are served by micro eNodeBs are added to an NRT of the cell served by a macro eNodeB, and the macro eNodeB does not perform PCI confusion detection. If the serving cell and the detected neighboring cell are both served by macro eNodeBs or the serving cell is served by a macro eNodeB, this feature does not take special measures.
Enhancement None
Dependency
UE This feature requires support from UEs.
Other features This feature requires the TDLOFD-002001 Automatic Neighbour Relation (ANR) and TDLOFD-002007 PCI Collision Detection & Self-Optimization features.
5.1.8 TDLOFD-081209 Automatic Congestion Handling Availability This feature is available as of LTE TDD eRAN8.1.
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Summary Based on condition-based adaptive parameter adjustment rules predefined in an eNodeB, the eNodeB periodically determines whether to enable adaptive parameter adjustment for a cell based on the monitored results, including UE number, physical resource block (PRB) usage, and control channel element (CCE) usage on the physical downlink control channel (PDCCH) in the cell. If the monitored results meet the conditions for parameter adjustments, the eNodeB automatically adjusts parameters to improve network performance.
Benefits In heavy traffic scenarios, the eNodeB automatically adjusts parameters and provides the following benefits:
Improved network performance and user experience
Simplified network maintenance and reduced manpower costs
Description The eNodeB determines whether to enable adaptive parameter adjustment based on related adjustment conditions and the monitored results, including UE number, PRB usage, and CCE usage on the PDCCH. During adaptive parameter adjustment, the eNodeB performs the following operations:
Collecting data The eNodeB periodically collects data source for predefined condition-based adaptive parameter adjustment rules.
Evaluating conditions The eNodeB compares collected data with the predefined parameter adjustment rules. If the comparison result does not meet the criteria for parameter adjustment rules, the process in this period ends. If the comparison result meets the criteria for parameter adjustment rules, parameter adjustment is triggered.
Adjusting parameters The eNodeB adjusts parameters meeting related parameter adjustment rules based on the predefined parameter adjustment measures.
With periodic execution of the preceding three operations, this feature helps monitor the network load in a timely manner and automatic performs parameter adjustments to improve network performance. Figure 5-4 Procedure for automatic congestion handling
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Enhancement Many condition-based adaptive parameter adjustment rules are added to eRAN11.0. In eRAN11.1, adaptive parameter adjustment rules based on interference mitigation are added, enhancing interference resistance for PUCCHs in heavy traffic scenarios and increasing downlink cell throughout.
Dependency None
5.1.9 TDLOFD-002011 Antenna Fault Detection Availability This feature was introduced in LTE TDD eRAN2.1.
Summary Antenna system and radio frequency (RF) channel faults are caused by the following: 1.
Incorrect project installation during creation, relocation, or optimization.
2.
Natural or external changes.
This feature detects faults on LTE antennas and allows users to detect and locate antenna faults. In addition, this feature does not require additional instruments for measuring eNodeBs at the site.
Benefits This feature improves the efficiency and accuracy of fault diagnosis and reduces project cost.
Description The antenna system plays an important role in mobile communications. The performance of the entire network is affected by the following problems:
Inappropriate type or location of the antenna system
Incorrectly configured parameters of the antenna system
Faulty antenna system
This feature allows eNodeBs to detect the following faults and report related alarms:
Weak received signal
Imbalance of received signals between the main and the diversity
Abnormal voltage standing wave ratio (VSWR)
Enhancement None
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Dependency None
5.1.10 TDLOFD-002012 Cell Outage Detection and Compensation Availability This feature was introduced in LTE TDD eRAN2.1.
Summary This feature allows eNodeB to automatically detect cell outage and adjust mobility-related RRM parameters to compensate outage cells.
Benefits This feature shortens the duration required to detect cell outages and maintains user services in the outage cell to the extent possible.
Description Cell outage is a critical situation, especially when there is only one frequency or RAT. It leads to service failure or significant KPI degradation. If there are alternative frequencies/RATs, hand over UEs from the outage cell to the inter-frequency or inter-RAT cell instead of compensating the coverage of surrounding cells. This feature consists of cell outage detection, RRM compensation, and cell outage recovery.
Cell outage detection Monitors both pre-defined alarms and cell KPIs in real time. According to the pre-defined alarms, the system detects whether the cell is out of service. KPI monitoring helps detect abnormal outage cases that will not trigger alarms through cell KPI degradation, including sleeping cells. Note that the KPI threshold is configurable by operators.
RRM compensation Adjusts the mobility-related RRM parameters to allow UE handovers to the surrounding cells for service continuity. In addition, the outage cell is added into the blacklist to prevent handover or reselection from neighboring cells. The priority for handover triggering is defined in the mobility features to maintain service continuity.
Cell outage recovery After cell outage is detected, the system recovers the cell. After outage recovery, the system reverses the compensation.
Enhancement To accelerate the cell outage detection process, LTE TDD eRAN6.0 introduces the assisted cell outage detection method. This method is independent of KPI measurement and detects cell outage by checking internal eNodeB counters at 5 minute intervals. When the counter values exceed the specified thresholds, the eNodeB reports the check results to the U2000. The U2000 then determines that a cell outage has occurred.
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In eRAN7.0: KPI accumulation is introduced for low traffic cell outage detection. When the KPIs number of one period is lower than the configured threshold, it will be accumulated to the next period till accumulated KPIs are more than the threshold, and then the system will calculate abnormal KPIs in accumulated periods to detect cell outage. In CODC SON Log, it will register the key KPIs information of Cell outage detection and Cell outage recovery for operator observation and analysis.
Dependency This feature requires the OSS feature WOFD-171000 Cell Outage Detection and Recovery-LTE. If an operator has deployed a GSM and UMTS network, RRM compensation can be improved by using these two optional features:
TDLOFD-001019 PS Inter-RAT Mobility between E-UTRAN and UTRAN
TDLOFD-001020 PS Inter-RAT Mobility between E-UTRAN and GERAN
5.2 MLB 5.2.1 TDLOFD-001032 Intra-LTE Load Balancing Availability This feature is available as of LTE TDD eRAN2.1.
Summary This feature coordinates load distribution among inter-frequency neighboring cells.
Benefits Utilizes the network resource efficiently. Improves system capacity. Reduces the possibility of system overload. Improves the access success rate.
Description In a multi-frequency network, if a frequency is in the high load state and other frequencies are not, it is recommended that this feature be enabled to relieve load imbalances among inter-frequency cells. With this feature enabled, the local cell checks the load status of itself. If the cell load exceeds a preset threshold, the local eNodeB collects the load status of inter-frequency neighboring cells of the local cell. If the load of a neighboring cell is lower than a preset threshold, the eNodeB transfers UEs from the local cell to the lightly loaded inter-frequency neighboring cell. Mobility load balancing (MLB) includes the following procedures: load measurement and evaluation, load information exchange, MLB decision, MLB execution. The cell load is represented by the physical resource block (PRB) usage.
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During load information exchange, the local cell collects the load status of neighboring E-UTRAN cells. MLB decision includes target cell selection and UE selection. In the MLB execution, UEs are transferred by using measurement-based handovers and blind handovers.
Enhancement
eRAN7.0 Added load measurement and evaluation by using the PRB evaluation value including the control channels. Operators can define the load evaluation criteria by themselves. Added frequency priorities for MLB. The eNodeB selects the target frequency for MLB based on the frequency priorities. Added blind MLB. Blind MLB is applicable to scenarios where no X2 interface is available or the X2 interface does not support load information exchange. Added measurement-based or blind redirections for load transfer.
eRAN8.1 Added load measurement and evaluation by using the PRB evaluation value excluding the control channels. Operators can define the load evaluation criteria by themselves. In addition, the filter factor for the PRB evaluation measurement is now configurable. Enhanced the UE selection policies, including the UE selection priorities and selection conditions. Added the handover performance assurance policies for UEs handed over to the target cell for MLB. To accommodate this, a timer that protects UEs from being repeatedly transferred for MLB and UE-specific coverage-related handover parameters are introduced.
eRAN11.0 Whether UEs can be selected based on QCIs for MLB and whether UEs are not preferentially selected based on QCIs for MLB are configurable on eNodeBs. Frequencies that can be selected as target frequencies based on QCIs are configurable on eNodeBs. eNodeBs can transfer only UEs with special SPIDs to dedicated cells.
eRAN11.1 The uplink and downlink PRB usage thresholds for triggering cell-level MLB can be configured separately. The uplink and downlink PRB usage thresholds for UE selection can be configured separately. The uplink and downlink PRB usage thresholds for target cell selection can be configured separately. The uplink and downlink MLB priorities of a neighboring E-UTRA frequency can be configured separately.
Dependency None
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5.2.2 TDLOFD-001123 Enhanced Intra-LTE Load Balancing Availability This feature was introduced in LTE TDD eRAN6.1.
Summary This feature resolves load imbalance between the serving cell and the inter-frequency neighboring cells under the same eNodeB.
Benefits This feature maximizes the network resource efficiency and improves the UE throughput.
Description This feature applies when the UE throughput in the neighboring cell is greater than that in the serving cell but the number of UEs in the neighboring cell is less than that in the serving cell. The load balancing procedure includes the following steps: load measurement and evaluation, load information exchange, load balancing decision, execution of measurement and handover. The serving and neighboring cells perform load balancing as follows: 1.
The serving cell measures the number of UEs within itself and at the same time receives the information about the number of UEs in the neighboring cell.
2.
The serving cell compares the two numbers. If the number of UEs within itself is greater than that in the neighboring cell, the serving cell triggers a handover to the neighboring cell.
3.
The serving cell selects UEs for the handover based on the following principles:
4.
−
If the neighboring cell covers a small area, the serving cell selects the UEs located in the center of the cell.
−
If the neighboring cell covers a large area, the serving cell selects the UEs located at the edge of the cell.
The serving cell hands over UEs to the neighboring cell.
Enhanced intra-LTE load balancing applies to the scenarios where coverage overlaps between multiple inter-frequency LTE cells.
Enhancement None
Dependency The serving cell and inter-frequency neighboring cell must belong to the same eNodeB. This feature does not apply to micro eNodeBs.
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5.2.3 TDLOFD-070215 Intra-LTE User Number Load Balancing Availability This feature is available as of LTE TDD eRAN7.0. This feature is available in micro eNodeBs as of LTE TDD eRAN8.0.
Summary This feature resolves user number load imbalances between cells and frequencies.
Benefits This feature achieves better utilization of network resources and balance user number to reduce the probability of burst traffic.
Description Intra-LTE User Number Load Balancing contains connected mode and idle mode. It is recommended in commercial LTE networks with multiple LTE frequencies where one frequency has a higher user number but other frequencies have lower user number. For connected mode, serving cell measures its own cell user number, if the number exceeds a preset threshold, the serving cell will send handover request to the neighboring cells which shall acknowledge or reject handover judged by their own user number load. For idle mode, users in normal RRC release procedure can be released to different frequency on configured proportion, by using Dedicated Priority within RRC Connection Release message. This function can precisely distribute idle users to different frequency as operators wish. Especially, if we set the proportion of micro frequency to 100% highest priority, idle users in micro coverage will only camp on micro's frequency, which is called Fast Discovery of Micro, it is quite meaningful to the scenario of absorbing users and traffic volume by micro site. Intra-LTE User Number Load Balancing is used in scenarios where inter-frequency LTE cells have highly overlapping coverage.
Enhancement
eRAN8.1 Enhanced the UE selection policies, including the UE selection priorities and selection conditions. Added the handover performance assurance policies for UEs handed over to the target cell for MLB. To accommodate this, a timer that protects UEs from being repeatedly transferred for MLB and UE-specific coverage-related handover parameters are introduced.
eRAN11.0 Whether UEs can be selected based on QCIs for MLB and whether UEs are not preferentially selected based on QCIs for MLB are configurable on eNodeBs. Frequencies that can be selected as target frequencies based on QCIs are configurable on eNodeBs. eNodeBs can transfer only UEs with special SPIDs to dedicated cells.
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In user-number-based inter-frequency MLB, when collecting the number of UEs, the eNodeB can be set to collect the actual number of UEs or the weight-factor number of UEs.
eRAN11.1 The uplink and downlink PRB usage thresholds for triggering cell-level MLB can be configured separately. The uplink and downlink PRB usage thresholds for UE selection can be configured separately. The uplink and downlink PRB usage thresholds for target cell selection can be configured separately. The uplink and downlink MLB priorities of a neighboring E-UTRA frequency can be configured separately.
Dependency None
5.2.4 TDLOFD-081210 Multi-RRU Cell Load Balancing Availability This feature is:
Available in macro eNodeBs and LampSite eNodeBs as of LTE TDD eRAN8.1.
Not available in micro eNodeBs.
Summary This feature enables an eNodeB to transfer certain uplink-synchronized UEs in a multi-RRU cell to neighboring cells by using PRB-usage-based inter-frequency mobility load balancing (MLB) if an RRU that serves the multi-RRU cell is in the high-load state.
Benefits This feature offloads traffic from an RRU in the high-load state in a multi-RRU cell and increases UE throughput of a single RRU.
Description For a multi-RRU cell, this feature allows the eNodeB to evaluate the PRB usage of each RRU and to select the maximum RRU PRB usage as the cell PRB usage used for evaluating whether to trigger MLB. When selecting UEs, in addition to other UE selection conditions in PRB-usage-based inter-frequency MLB, the eNodeB also considers the PRB usage of the working RRUs that serve UEs.
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Figure 5-5 MLB triggering condition
Figure 5-6 UE selection
Enhancement None
Dependency This feature requires the TDLOFD-001032 Intra-LTE Load Balancing feature.
5.2.5 TDLOFD-001044 Inter-RAT Load Sharing to UTRAN Availability This feature is available as of LTE TDD eRAN2.1.
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Summary This feature is used in the overlapping area of UTRAN and E-UTRAN networks and the two systems' load is unbalanced.
Benefits Improves the system resource utilization rate and guarantees the service requirements. Reduces the possibility of system overload and decreases the service drop rate.
Description In scenarios where both E-UTRAN and UTRAN are deployed, if an E-UTRA frequency is in the high load state and UTRA frequencies are not, it is recommended that this feature be enabled to relieve load imbalances among inter-RAT cells. With this feature enabled, the local cell checks the load status of itself. If the cell load exceeds a preset threshold, the local eNodeB collects the load status of neighboring UTRAN cells of the local cell. If the load of a neighboring cell is lower than a preset threshold, the eNodeB transfers UEs from the local cell to the lightly loaded neighboring UTRAN cell. Mobility load balancing (MLB) includes the following procedures: load measurement and evaluation, load information exchange, MLB decision, MLB execution. The cell load is represented by the physical resource block (PRB) usage and the number of uplink-synchronized UEs in a cell. During load information exchange, the local cell collects the load status of neighboring UTRAN cells. MLB decision includes target cell selection and UE selection. UEs are transferred to the target cell for MLB by using one of the following methods: measurement-based handover, blind handover, measurement-based redirection, and blind redirection.
Enhancement In eRAN3.0, the eNodeB can select UEs in idle mode for load transfer and can transfer UEs by using redirection based on the MLB-dedicated frequency priorities. In eRAN7.0, the eNodeB supports frequency priorities for MLB. The eNodeB selects the target frequency for MLB based on the frequency priorities. In eRAN8.0, the eNodeB supports the load measurement and evaluation based on the number of UL-synchronized UEs in a cell to deploy MLB based on the number of UL-synchronized UEs in a cell.
Dependency UEs must support LTE TDD and UMTS networks.
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LTE TDD Optional Feature Description
5 O&M
5.2.6 TDLOFD-001045 Inter-RAT Load Sharing to GERAN Availability This feature was introduced in LTE TDD eRAN2.1.
Summary This feature is used when the LTE and GSM systems cover the same area and the load of the two systems is unbalanced.
Benefits This feature provides the following benefits:
Improves the system resource utilization rate while guaranteeing QoS.
Reduces the possibility of system overload.
Decreases the service drop rate.
Description In a commercial LTE network, LTE cells have high load but the load of GERAN cells is low because of service differentiation. To resolve this problem, the eNodeB uses the load balancing algorithm. The LTE cell measures and evaluates the cell load, and then determines whether to perform a handover to a neighboring GERAN cell. If the LTE cell load is higher than a specific threshold, some UEs are handed over to the GERAN cell. The cell load is defined as the PRB utilization rate. For details, see 3GPP TS 36.314. There is only one type of inter-LTE load balance: active load balance. The active load balance procedure includes the following steps: load measurement and evaluation, load balance triggering, UE-dedicate priority update, UE selection for handover, and handover execution.
Enhancement None
Dependency UEs must support LTE TDD and GSM. This feature does not apply to micro eNodeBs. This feature requires TDLOFD-001020 PS Inter-RAT Mobility between E-UTRAN and GERAN.
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LTE TDD Optional Feature Description
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5.3 Power Saving 5.3.1 TDLOFD-001039 RF Channel Intelligent Shutdown Availability This feature is:
Available in macro eNodeBs as of LTE TDD eRAN2.1.
Available in micro eNodeBs as of LTE TDD eRAN6.1.
Not available in LampSite eNodeBs.
Summary When no traffic is carried by a cell configured in MIMO mode, only some of the transmit channels need to be switched on with the PAs of other transmit channels shut down. In this way, the power consumption of the no-load eNodeB is decreased. When there is traffic, the PAs are switched on automatically to have the cell run normally again.
Benefits If there is no load, the eNodeB can shut down the PAs of some transmit channels, thereby reducing the eNodeB power consumption.
Description An eNodeB in the LTE system is generally configured with two or four antennas. The traffic in the cell varies by time. In some periods (operators can customize the periods), for example, from the midnight to the early morning, there is no traffic. When the eNodeB detects the idle status, it keeps only one functional RF transmit channel (if there are two transmit channels) or two functional RF transmit channels (if there are four transmit channels) to decrease power consumption. When a UE accesses the cell or the periods end, the eNodeB can automatically switch on the PAs that were shut down. Then, the cell recovers to the normal state and continues with services. The service quality of the cell is not affected.
Enhancement None
Dependency A cell has two or four transmit antennas, and the cell bandwidth is greater than or equal to 10 MHz. This feature does not work with the following features:
TDLOFD-001075 SFN
TDLOFD-002008 Adaptive SFN/SDMA
TDLOFD-001098 Inter-BBP SFN
TDLOFD-001080 Inter-BBU SFN
TDLOFD-001081 Inter-BBP Adaptive SFN/SDMA
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LTE TDD Optional Feature Description
5 O&M
TDLOFD-001082 Inter-BBU Adaptive SFN/SDMA
5.3.2 TDLOFD-001040 Low Power Consumption Mode Availability This feature is:
Available in macro eNodeBs as of LTE TDD eRAN2.1.
Not available in micro eNodeBs.
Not available in LampSite eNodeBs.
Summary In some scenarios, such as a power outage, an eNodeB can be instructed to work in low power consumption mode. This mode can help prolong the in-service time of an eNodeB powered by battery.
Benefits When an eNodeB is derated, its power consumption is reduced and its in-service time powered by battery is prolonged. Therefore, the possibility of the eNodeB being out of service is reduced even during periods of extended power outages.
Description Low power consumption mode is implemented in four levels. If the power supply has not recovered to its normal state and the power consumption of a level reaches the time threshold preset by the operator, the eNodeB enters the low power consumption mode of the next level until the cell is out of service. Low power consumption mode of the eNodeB is triggered by one of the following conditions:
Power system alarms If the power insufficiency or power failure lasts for the period preset by the operator, an alarm is reported to trigger low power consumption mode of the eNodeB.
Command delivered by the EMS The operator can deliver a command through the EMS to instruct the eNodeB to enter or exit low power consumption mode.
Enhancement None
Dependency This feature does not apply to micro eNodeBs. This feature cannot be used with the following features:
TDLOFD-001080 Inter-BBU SFN
TDLOFD-001082 Inter-BBU Adaptive SFN/SDMA
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5.3.3 TDLOFD-001041 Power Consumption Monitoring Availability This feature is:
Available in macro eNodeBs as of LTE TDD eRAN2.1.
Not available in micro eNodeBs.
Not available in LampSite eNodeBs.
Summary The eNodeB reports the power consumption status to the element management system (EMS). On the EMS, operators can monitor the change in eNodeB power consumption, and a power consumption report can be generated.
Benefits The eNodeB reports the power consumption status to the EMS. Therefore, operators can monitor eNodeB power consumption. With the power consumption report, operators can exactly know the benefits delivered by the decrease in power consumption.
Description The eNodeB periodically monitors the power of each monitoring point and reports the power consumption within a period. The EMS receives and collects all data about power consumption. On the EMS, operators can observe the change in power consumption and analyze the power consumption according to the statistical report generated by the EMS.
Enhancement None
Dependency This feature is not available in integrated micro eNodeBs. UPEU boards except UPEUa and UPEUb boards support this feature.
5.3.4 TDLOFD-001042 Intelligent Power-Off of Carriers in the Same Coverage Availability This feature is:
Available in macro eNodeBs as of LTE TDD eRAN2.1.
Available in micro eNodeBs as of LTE TDD eRAN8.0.
Not available in LampSite eNodeBs.
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LTE TDD Optional Feature Description
5 O&M
Summary When there is little traffic in an area covered by multiple carriers, some of the carriers can be blocked, and all services can be automatically taken over by the carriers that remain in service. When the traffic increases to a preset threshold, the carriers that were blocked can be automatically unblocked again to provide services.
Benefits When there is little traffic in an area covered by multiple carriers, some of the carriers can be blocked, and all services can be automatically taken over by the carriers that remain in service. This feature helps reduce the eNodeB power consumption without affecting service quality.
Description When multiple carriers provide coverage for the same area, the traffic of the area varies by time. In some certain periods, for example from the midnight to the early morning (the periods can be preset by the operator), the traffic is light. When the eNodeB detects that the traffic is light, it triggers UEs to switch services on some carriers to other carriers and then blocks the carriers without any load, thereby decreasing power consumption. When the traffic increases or the preset period ends, the eNodeB automatically switches on the carriers that were blocked to recover the functionality of the carriers. In this way, system capacity is increased without affecting service quality.
Enhancement None
Dependency This feature requires TDLBFD-00201802 Coverage Based Inter-frequency Handover. This feature does not work with the following features:
TDLOFD-001080 Inter-BBU SFN
TDLOFD-001082 Inter-BBU Adaptive SFN/SDMA
This feature must be used on networks configured with intra-eNodeB inter-frequency co-coverage neighboring cells.
5.3.5 TDLOFD-001056 PSU Intelligent Sleep Mode Availability This feature is available as of LTE TDD eRAN2.2.
Summary With the PSU Intelligent Sleep Mode feature, the eNodeB switches on or off some of power supply units (PSUs) based on power consumption, thereby reducing the power consumption.
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Benefits When traffic is low, the eNodeB switches off some of PSUs to reduce power consumption. In such a case, each eNodeB may switch off three PSUs to reduce power consumption by 4% to 5%.
Description This feature applies to AC-powered eNodeBs configured with Huawei PSUs, which are used to convert AC to DC, and with Huawei power monitoring units (PMUs). The number of PSUs required is determined by the maximum power consumption of an eNodeB. This feature ensures that the eNodeB operates normally when fully loaded. The eNodeB, however, seldom operates at maximum capacity. As a result, each PSU in the eNodeB normally works at partial output power. The efficiency of PSU power conversion is directly proportional to its output power. Therefore, a low power PSU power conversion efficiency results in a low power efficiency overall. If an eNodeB is configured with multiple PSUs, PSU intelligent sleep mode can shut down one or more PSUs when the eNodeB is lightly loaded. This way, the remaining PSUs are fully loaded when operating, thereby ensuring the highest working efficiency.
Enhancement None
Dependency eNodeBs are AC powered and configured with storage batteries and Huawei PMUs that support this feature to manage the power system. This feature is not available in integrated micro eNodeBs.
5.3.6 TDLOFD-001070 Symbol Power Saving Availability This feature is:
Available in macro eNodeBs as of LTE TDD eRAN3.0.
Not available in micro eNodeBs.
Not available in LampSite eNodeBs.
Summary This feature enables the eNodeB to turn off power amplifiers (PAs) during the periods for the symbols that do not contain any data. In addition, the eNodeB takes advantages of multimedia broadcast multicast service single frequency network (MBSFN) subframes to further reduce reference signals so that PAs can be turned off for more symbols.
Benefits When traffic is low, the eNodeB can shut down PAs of some symbols to reduce the eNodeB power consumption and the static power consumption of PAs.
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LTE TDD Optional Feature Description
5 O&M
Description Among the eNodeB components, PAs consume the majority of power. PAs require static consumption even when no signals are transmitted. If PAs can be quickly enabled and disabled, the eNodeB can use the Symbol Power Saving feature. With this feature, the eNodeB can shut down PAs of some symbols to reduce static power consumption. To ensure data integrity, the eNodeB determines the time to enable or disable PAs. For example, if a cell does not serve any activated UEs, only reference signals in some subframes need to be transmitted. In this case, the eNodeB can shut down PAs in the orthogonal frequency division system without reference signals. If a cell is not configured with the broadcast multicast service (BCMCS), the eNodeB can configure some empty subframes in the multimedia broadcast multicast service single frequency network (MBSFN) subframes. If an MBSFN subframe is configured with only one subframe and contains reference signals to transmit only in the first symbol, the symbol of the subframe can be configured as an empty symbol. This way, PAs corresponding to such symbols can be shut down to reduce power consumption. Figure 5-7 Symbol Power Saving
Enhancement None
Dependency This feature applies only to macro eNodeBs. Enhanced symbol power saving mode requires UE support. Specifically, UEs must be capable of identifying and handling MBSFN subframes related to the serving and neighboring cells.
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LTE TDD Optional Feature Description
5 O&M
Only RRU3232/RRU3251/RRU3252/RRU3256/RRU3253/RRU3259/RRU3221E modules support this feature. This feature is not available in integrated micro eNodeBs.
5.3.7 TDLOFD-001071 Intelligent Battery Management Availability This feature was introduced in LTE TDD eRAN3.0.
Summary With this feature, the battery management mode automatically changes depending on the selected grid type, which prolongs the battery lifespan. The battery self-protection function is triggered under high temperature to prevent battery overuse and subsequent damage. The battery runtime is displayed after the mains supply is cut off. By considering the runtime, operators can take proactive measures to prevent service interruption due to power supply cutoff.
Benefits This feature provides the following benefits:
Prolongs battery lifespan
Reduces energy consumption
Reduces OPEX
Improves system stability
Automatic change of the battery management mode:
Description The PMU board records the number of times power supply is cut off and the duration of each cutoff. Then, the PMU board determines which grid type is selected and correspondingly activates a specific power management mode. In grid types 1 and 2, batteries can enter a hibernation state in which batteries do not charge or discharge, which helps prolong battery lifespan. Power Supply Cutoff Duration Within 15 Days (Hours)
Grid Type
Charge and Discharg e Mode
Current Limitatio n Valve
Hibernat ion Voltage (V)
Hibernat ion Duration (Days)
Estimate d Battery Lifespan Improve ment Rate
≤5
1
Mode A
0.10 C
52
13
100%
5 to 30
2
Mode B
0.15 C
52
6
50%
30 to 120
3
Mode C
0.15 C
N/A
N/A
0%
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Power Supply Cutoff Duration Within 15 Days (Hours)
Grid Type
Charge and Discharg e Mode
Current Limitatio n Valve
Hibernat ion Voltage (V)
Hibernat ion Duration (Days)
Estimate d Battery Lifespan Improve ment Rate
≥120
4
Mode C
0.15
N/A
N/A
0%
This function is under license control. In addition, this function is disabled by default and can be enabled by running an MML command.
Self-protection under high temperature: When batteries work at a temperature exceeding the threshold for entering the floating charge state for 5 minutes, they enter this state and no alarms are generated. When batteries work at a temperature exceeding the threshold for the self-protection function for 5 minutes, they are automatically powered off or the battery voltage is automatically adjusted.
Battery runtime display: After the mains supply is cut off, the eNodeB calculates the runtime of batteries based on the remaining power capacity, discharge current, and other data. This runtime can be queried by running an MML command. The following formula is used to calculate the runtime of batteries: Runtime of batteries = (Remaining power capacity x Total power capacity x Discharge efficiency)/(Mean discharge current x Aging coefficient)
Enhancement None
Dependency This feature only applies to the power module PMU02B. This feature does not apply to micro eNodeBs.
5.4 Antenna Management 5.4.1 TDLOFD-001024 Remote Electrical Tilt Control Availability This feature is:
Available in macro eNodeBs as of LTE TDD eRAN1.0.
Not available in micro eNodeBs.
Not available in LampSite eNodeBs.
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LTE TDD Optional Feature Description
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Summary Remote Electrical Tilt Control improves the efficiency and minimizes the OM cost for adjusting the downtilt of the antenna. Huawei LTE RET solution complies with the AISG2.0 specification, and it is backward compatible with AISG1.1.
Benefits The application of the RET prominently improves the efficiency and minimizes the OM cost for adjusting the downtilt of the antenna. The application of the RET brings the following benefits:
The RET antennas at multiple sites can be adjusted remotely within a short period. This improves the efficiency and reduces the cost of network optimization.
Adjustment of the RET antenna can be performed in all weather conditions.
The RET antennas can be deployed on some sites that are difficult to access.
RET downtilt adjustment can keep the coverage pattern undistorted, therefore strengthening the antenna signal and reducing neighboring cell interference.
Description The Remote Electrical Tilt (RET) refers to an antenna system whose downtilt is controlled electrically and remotely. After an antenna is installed, the downtilt of the antenna needs to be adjusted to optimize the network. In this situation, the phases of signals that reach the elements of the array antenna can be adjusted under the electrical control. Then, the vertical pattern of the antenna can be changed. The phase shifter inside the antenna can be adjusted through the step motor outside the antenna. The downtilt of the RET antenna can be adjusted when the system is powered on, and the downtilt can be monitored in real time. Therefore, the remote precise adjustment of the downtilt of the antenna can be achieved. Huawei LTE RET solution complies with the AISG2.0 specification, and it is compatible with AISG1.1.
Enhancement In LTE TDD eRAN11.1, two-dimensional RET is introduced to support China Mobile corporate specifications and to support adjusting the horizontal azimuth based on the weighting factor of the antenna.
Dependency This feature is not available in integrated micro eNodeBs. This feature is not available in scenarios where the TX and RX channels of an RRU3232, RRU3252, or RRU3256 are changed from 4T4R to double 2T2R.
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LTE TDD Optional Feature Description
6 Acronyms and Abbreviations
6
Acronyms and Abbreviations
3GPP
3rd Generation Partnership Project
ABS
almost-blank subframe
ACK
acknowledgment
ACL
Access Control List
AES
Advanced Encryption Standard
AFC
Automatic Frequency Control
AH
Authentication Header
AMBR
Aggregate Maximum Bit Rate
AMC
Adaptive Modulation and Coding
AMR
Adaptive Multi-Rate
ANR
Automatic Neighbor Relation
ARP
Allocation/Retention Priority
ARQ
Automatic Repeat Request
BCH
Broadcast Channel
BCCH
Broadcast Control Channel
BLER
Block Error Rate
CA
carrier aggregation
C/I
Carrier-to-Interference Power Ratio
CCCH
Common Control Channel
CDMA
Code Division Multiple Access
CEU
Cell Edge Users
CGI
Cell Global Identification
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LTE TDD Optional Feature Description
6 Acronyms and Abbreviations
CP
Cyclic Prefix
CPICH
Common Pilot Channel
CQI
Channel Quality Indicator
CRC
Cyclic Redundancy Check
CRS
Cell-specific reference signal
CSI-RS
Channel state information reference signal
DCCH
Dedicated Control Channel
DHCP
Dynamic Host Configuration Protocol
DiffServ
Differentiated Services
DL-SCH
Downlink Shared Channel
DRB
Data Radio Bearer
DRX
Discontinuous Reception
DSCP
DiffServ Code Point
DTCH
Dedicated Traffic Channel
ECM
EPS Control Management
eCSFB
Enhanced CS Fallback
EDF
Early Deadline First
EF
Expedited Forwarding
eHRPD
Evolved high rate packet data
eICIC
Enhanced Inter-cell Interference Coordination
eMBMS
evolved Multimedia Broadcast Multimedia System
EMM
EPS Mobility Management
EMS
Element Management System
eNodeB
E-UTRAN NodeB
EPC
Evolved Packet Core
EPS
Evolved Packet System
ESP
Encapsulation Security Payload
ETWS
Earthquake and Tsunami Warning System
E-UTRA
Evolved –Universal Terrestrial Radio Access
FCPSS
Fault, Configuration, Performance, Security and Software Managements
FDD
Frequency Division Duplex
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LTE TDD Optional Feature Description
6 Acronyms and Abbreviations
FEC
Forward Error Correction
FTP
File Transfer Protocol
GBR
Guaranteed Bit Rate
GERAN
GSM/EDGE Radio Access Network
GPS
Global Positioning System
HARQ
Hybrid Automatic Repeat Request
HII
High Interference Indicator
HMAC
Hash Message Authentication Code
HMAC_MD 5
HMAC Message Digest 5
HMAC_SH A
HMAC Secure Hash Algorithm
HO
Handover
HRPD
High Rate Packet Data
ICIC
Inter-cell Interference Coordination
IKE
Internet Key Exchange
IMS
IP Multimedia Service
IP PM
IP Performance Monitoring
IPsec
IP Security
IRC
Interference Rejection Combining
KPI
Key Performance Indicator
CME
Configuration Management Express
LMT
Local Maintenance Terminal
U2000
iManager U2000 MBB Network Management System
MAC
Medium Admission Control
MIB
Master Information Block
MCH
Multicast Channel
MCCH
Multicast Control Channel
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LTE TDD Optional Feature Description
6 Acronyms and Abbreviations
MCS
Modulation and Coding Scheme
MIMO
Multiple Input Multiple Output
min_GBR
Minimum Guaranteed Bit Rate
MME
Mobility Management Entity
MML
Man-Machine Language
MOS
Mean Opinion Score
MRC
Maximum-Ratio Combining
MTCH
Multicast Traffic Channel
MU-MIMO
Multiple User-MIMO
NACC
Network Assisted Cell Changed
NACK
Non acknowledgment
NAS
Non-Access Stratum
NRT
Neighboring Relation Table
OCXO
Oven Controlled Crystal Oscillator
OFDM
Orthogonal Frequency Division Multiplexing
OFDMA
Orthogonal Frequency Division Multiplexing Access
OI
Overload Indicator
OMC
Operation and Maintenance Center
OOK
On-Off-Keying
PBCH
Physical Broadcast Channel
PCC
Primary Component Carrier
PCCH
Paging Control Channel
PCFICH
Physical Control Format Indicator Channel
PCH
Paging Channel
PCI
Physical Cell Identity
PDB
Packet Delay Budget
PDCCH
Physical Downlink Control Channel
PDCP
Packet Data Convergence Protocol
PDH
Plesiochronous Digital Hierarchy
PDSCH
Physical Downlink Shared Channel
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LTE TDD Optional Feature Description
6 Acronyms and Abbreviations
PF
Proportional Fair
PHB
Per-Hop Behavior
PHICH
Physical Hybrid ARQ Indicator Channel
PM
Performance Measurement
PLMN
Public Land Mobile Network
PMCH
Physical Multicast Channel
PRACH
Physical Random Access Channel
PUCCH
Physical Uplink Control Channel
PUSCH
Physical Uplink Shared Channel
QAM
Quadrature Amplitude Modulation
QCI
QoS Class Identifier
QoS
Quality of Service
QPSK
Quadrature Phase Shift Keying
RA
Random Access
RACH
Random Access Channel
RAM
Random Access Memory
RAT
Radio Access Technology
RB
Resource Block
RCU
Radio Control Unit
RET
Remote Electrical Tilt
RF
Radio Frequency
RLC
Radio Link Control
RRC
Radio Resource Control
RRM
Radio Resource Management
RRU
Remote Radio Unit
RS
Reference Signal
RSRP
Reference Signal Received Power
RSRQ
Reference Signal Received Quality
RSSI
Received Signal Strength Indicator
RTT
Round Trip Time
RV
Redundancy Version
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LTE TDD Optional Feature Description
6 Acronyms and Abbreviations
Rx
Receive
S1
interface between EPC and E-UTRAN
SBT
Smart Bias Tee
SCC
Secondary Component Carrier
SC-FDMA
Single Carrier-Frequency Division Multiple Access
SCTP
Stream Control Transmission Protocol
SDH
Synchronous Digital Hierarchy
SFBC
Space Frequency Block Coding
SFP
Small Form – factor Pluggable
SGW
Serving Gateway
SIB
System Information Block
SID
Silence Indicator
SINR
Signal to Interference plus Noise Ratio
SRB
Signaling Radio Bearer
SRS
Sounding Reference Signal
SSL
Security Socket Layer
STBC
Space Time Block Coding
STMA
Smart TMA
TAC
Transport Admission Control
TCP
Transmission Control Protocol
TDD
Time Division Duplex
TMA
Tower Mounted Amplifier
TMF
Traced Message Files
ToS
Type of Service
TTI
Transmission Time Interval
Tx
Transmission
UE
User Equipment
UL-SCH
Uplink Shared Channel
USB
Universal Serial Bus
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LTE TDD Optional Feature Description
6 Acronyms and Abbreviations
VLAN
Virtual Local Area Network
VoIP
Voice over IP
WRR
Weighted Round Robin
X2
interface between eNodeBs
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