Flexi Multiradio 10 Bts Edge Feature Descriptions
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GSM/EDGE BSS, Rel. RG30(BSS), Operating Documentation, Issue 08, Change Delivery 01 Flexi Multiradio 10 Base Station EDGE Feature Descriptions DN09167685 Issue 01F Approval Date 2015-08-21
Flexi Multiradio 10 Base Station EDGE Feature Descriptions
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Table of Contents This document has 142 pages
Summary of changes................................................................... 10
1
Overview of features in Flexi Multiradio BTS software release GF1 ......................................................................................................11
2 2.1 2.2 2.3
2.10 2.11 2.12 2.13 2.14 2.15 2.16 2.17 2.18 2.19 2.19.1
Data/Voice....................................................................................12 BSS20088 Dual Transfer Mode................................................... 12 BSS9006 General Packet Radio Service (GPRS)....................... 12 BSS10083 Enhanced General Packet Radio Service (MCS-1 MSC-9)......................................................................................... 13 BSS7003 High Speed Circuit Switched Data and BSS7037 14.4 kbit/s Data Services..................................................................... 16 BSS10004 Adaptive Multi Rate Codec (AMR)............................. 17 BSS7005 Intelligent Frequency Hopping and BSS6114 Intelligent Underlay-Overlay......................................................................... 18 BSS20960 Wideband AMR and BSS21118 TFO for AMR...........19 Long Reach TCH TSL..................................................................19 BSS101482 Extended Cell functionalities for Flexi Multiradio BTS. 19 BSS21388 Random Fill Bits.........................................................22 BSS21309 OSC Half Rate with SAIC MS.................................... 22 BSS21534 OSC Full Rate with SAIC MS.....................................24 BSS21325 8k TRAU for OSC AMR FR .......................................24 BSS21313 OSC support for VAMOS handsets............................25 BSS21537 AQPSK with VAMOS 2 Handsets.............................. 26 RG301666 EGPRS Downlink Power Control...............................28 BSS21542 OSC Capability Test for Handsets............................. 29 RG602124 Composite Multi Site Transmission............................30 RG602125 High Speed Rail Handover........................................ 32 CMST configuration restrictions(BSC):........................................ 33
3 3.1 3.2 3.3 3.4
Interworking..................................................................................36 BSS10101 GSM-WCDMA Interworking....................................... 36 BSS11086 Support for Enhanced Measurement Report............. 36 BSS21520: RF Sharing GSM - LTE............................................. 37 Collecting logs using Snapshot feature........................................38
4 4.1 4.2 4.3 4.3.1 4.4
Operability.................................................................................... 40 2G Flexi BTS Manager Compatibility Launcher........................... 40 BTS Trace Tool.............................................................................42 Antenna VSWR measurement..................................................... 42 Antenna boosting on TCH-only TRX antenna lines..................... 44 BSC download of Abis mapping...................................................44
2.4 2.5 2.6 2.7 2.8 2.9
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4.5
4.34 4.35 4.36 4.37 4.38
BSS20847 Automatic commissioning of the Flexi Multiradio BTS GSM/EDGE.................................................................................. 45 BSS20817 End to End Downlink Abis Performance Monitor ...... 46 BSS20063 Space Time Interference Rejection Combining..........46 BSS20040 User Access Level Control (UALC)............................47 BSS11047 Intelligent shutdown for Flexi Multiradio BTS GSM/EDGE.................................................................................. 49 Remote mode of 2G Flexi BTS Site Manager .............................50 BSS10063 Rx Antenna Supervision by Comparing RSSI............51 BSS9068 BTS SW management................................................. 53 BSS9058 BTS fault recovery....................................................... 54 BSS9063 Abis loop test............................................................... 54 BSS9062 BTS supervision...........................................................54 BSS9061 Temperature control system.........................................55 BSS9060 TRX Test...................................................................... 55 TRX Loop Test............................................................................. 57 BSS9059 Nokia BTS resets......................................................... 57 BTS Auto-detection...................................................................... 58 BSS9056 Auto-detection of Site Configuration............................ 58 48 V DC input voltage supervision............................................... 58 BSS20958 Energy saving mode for BCCH TRX..........................59 Resource Allocation Algorithm..................................................... 59 Overview...................................................................................... 59 General resource allocation rules................................................ 59 RF allocation procedure............................................................... 60 Alarms due to resource allocation................................................65 Smart BCCH recovery..................................................................65 BSS21362 Fast BSS Restart....................................................... 67 BSS21316 Flexi BTS Autoconnection..........................................68 BSS101574: Air Path Loss Measurement ...................................68 BSS101583 Precise Rx Level Management................................ 69 BSS101584 Precise Timing Advance Management.................... 69 BSS101585 Precise Power Level Management.......................... 69 BSS101586 Adjacent Cell Rx Level Management.......................70 Power Cable Auto-detection........................................................ 70 Antenna Hopping......................................................................... 71 BSS101696 Small form-factor pluggable (SFP) Transceiver Diagnostics...................................................................................72 BSS20984: 2G TRX Automatic Power Down...............................72 RG301936: Intelligent MCPA TRX Shutdown.............................. 74 BSS101688 BSS support for FSM3............................................. 78 BSS10104 Intelligent Downlink Diversity..................................... 78 RG301980 CMST Support with FSM3 ........................................ 78
5 5.1 5.2
Site solutions................................................................................79 BSS10046 Multi BCF Control.......................................................79 BSS9055 Clock Synchronisation between Base Stations............79
4.6 4.7 4.8 4.9 4.10 4.11 4.12 4.13 4.14 4.15 4.16 4.17 4.18 4.19 4.20 4.20.1 4.21 4.22 4.23 4.23.1 4.23.2 4.23.3 4.23.4 4.23.5 4.24 4.25 4.26 4.27 4.28 4.29 4.30 4.31 4.32 4.33
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5.3 5.4 5.4.1 5.4.2 5.5 5.6 5.7 5.8 5.8.1 5.8.2 5.8.3 5.8.4 5.8.5 5.8.6 5.9 5.10 5.11 5.12 5.12.1 5.12.2 5.12.3 5.12.4 5.12.5 5.13 5.14 5.15 5.16 5.17
1 Pulse Per Second (PPS)...........................................................81 BSS10069 Synchronized BSS..................................................... 81 BSS20371 BSS Site Synchronisation Recovery Improvement....82 BSS11073 Recovery for BSS and Site Synchronisation.............. 82 Operating bands...........................................................................83 BTS2043 BTS External Alarms and Controls (EAC)....................85 BTS2020 RX antenna diversity.................................................... 85 BTS configurations.......................................................................86 Dedicated mode........................................................................... 86 Concurrent mode......................................................................... 86 Shared RX diversity..................................................................... 87 Antenna-optimized configurations................................................87 Feederless configurations............................................................ 88 Maximum configuration supported............................................... 89 Remote Electrical Tilt (RET).........................................................90 MHA types supported...................................................................91 RG301397 Co-siting with BS2xx..................................................91 RF Module/RRH chaining............................................................ 92 GSM - RF Module chaining..........................................................92 GSM - RRH chaining....................................................................93 Common BCCH chaining............................................................. 94 RF Module - RRH chaining.......................................................... 96 Examples of chained configurations............................................ 97 BSS21507 Flexible MCPA TX Power Pooling..............................99 RG301743: Adjustable UL RLT Increase Step...........................103 BSS101623 Energy Efficient Coverage..................................... 104 RG301726 Uplink Min RX level Based Access .........................104 RG301965 GPS 1PPS+TOD Sync Support...............................105
6 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 6.9
Basic GSM operation................................................................. 106 Static Power levels.....................................................................106 BSS21113 Increased dynamic SDCCH capacity....................... 106 BSS20872 Robust AMR signaling............................................. 106 BSS20588 TRAU bicasting in AMR FR/HR handover............... 108 Basic GSM features................................................................... 108 BSS6071 Enhanced Full Rate Codec........................................ 109 BTS2023 Downlink and uplink DTX........................................... 109 BTS2503 Compressed Abis timeslot allocation..........................110 BTS2067 Fast Associated Control Channel (FACCH) Call Setup... 110 BSS7036 Dynamic SDCCH Allocation....................................... 110 BTS2024 Synthesized frequency hopping..................................111 BTS2013 Baseband Frequency Hopping................................... 111 BTS2037 Air interface measurement pre-processing.................112 BTS2012 BTS time base reference from PCM...........................112 BTS2133 Short Message Service (SMS) point-to-point............. 112
6.10 6.11 6.12 6.13 6.14 6.15
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6.16 6.17
6
6.18 6.19 6.20 6.21 6.22 6.23 6.24 6.25 6.26 6.27 6.28 6.29 6.30
BTS2033 Short message cell broadcast.................................... 112 BSS6025 Short Message Service Cell Broadcast with Discontinuous Receiving (SMS-CB DRX).................................. 112 BSS6083 Mobile Station (MS) speed detection......................... 113 BSS20093 A5/3 ciphering.......................................................... 114 Multiple Operator BSS Configuration (MOBBS)......................... 115 BSS101411 Extended BCCH..................................................... 117 BSS21538 Extended Common Control Channel (CCCH)..........117 BSS21445 Packet Abis Congestion reaction............................. 117 BTS Overload Control................................................................ 118 RG301917 Triple RFM 3*80W in 1900 band..............................120 RG301703 FXEB support in BSS.............................................. 120 RG301704 5W Output Power Step size for Flexi Multiradio...... 120 RG301756 FXDB support in BSS.............................................. 120 RG301844 BSS Support for High Power RRH.......................... 121 RG302087 Narrow LTE RF Bandwidth...................................... 121
7 7.1 7.1.1 7.1.2 7.1.3 7.1.4 7.1.5 7.1.6 7.2 7.2.1 7.2.2 7.2.3 7.3 7.4 7.5 7.6 7.7 7.8 7.9 7.10 7.11 7.12 7.13 7.14 7.15 7.16 7.17 7.18
Transmission.............................................................................. 122 Basic transmission..................................................................... 122 Abis Trunk Transmission for E1 (ETSI) interface....................... 122 Abis Trunk Transmission Allocation for T1 (ANSI) Interface...... 122 Abis Trunk Signaling.................................................................. 123 Network Synchronisation........................................................... 123 BSS9065 Transmission Operability............................................124 BSS21234 Support for BTS PWE Counters at BSC/NetAct...... 124 Transmission solutions...............................................................125 PDH traffic routing...................................................................... 125 BSS30280 Abis loop protection................................................. 126 Redundant Abis Trunk................................................................127 BSS10045 Dynamic Abis allocation...........................................128 BSS5850 Satellite Abis.............................................................. 129 BSS21497 Enhanced satellite support.......................................129 BSS21439 Packet Abis Sync. ToP IEEE1588v2........................129 BSS21454 Packet Abis over Ethernet....................................... 130 BSS21438 Packet Abis over Satellite........................................ 130 BSS30450 Packet Abis Synchronous Ethernet......................... 131 BSS21440 Packet Abis over TDM............................................. 131 BSS21271 Abis Delay Measurement (TDM, PWE3)................. 133 BSS30395 Packet Abis Delay Measurement.............................134 BSS21503 FlexiPacket Radio Connectivity............................... 134 BSS101417 QoS Aware Ethernet Switching..............................135 BSS101459 Full GE Support in FIYB/FIQB............................... 136 BSS101414 Packet Abis Transport Media Conversion..............137 Functional description................................................................ 138 RG301994 Longer Sync Cable between FSMx & ESMx........... 140
8
Appendix A.................................................................................142
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List of Figures
Issue: 01F
Figure 1
Incremental Redundancy scheme...................................................... 15
Figure 2
Typical data throughputs for 14.4 kbit/s (non-transparent) and 9.6 kbit/s coding (this depends on the NW radio conditions)....................17
Figure 3
AQPSK constellation.......................................................................... 27
Figure 4
OSC Capability Test for Handsets...................................................... 29
Figure 5
Composite cell concept in multi-floor solution.................................... 31
Figure 6
CMST in railway environment.............................................................32
Figure 7
Collecting logs using Snapshot feature.............................................. 39
Figure 8
Compatibility launcher-local connection............................................. 40
Figure 9
Compatibility launcher-connecting......................................................41
Figure 10
Compatibility launcher-Create File option...........................................41
Figure 11
Uninstall versions of 2G Flexi BTS Site Manager...............................42
Figure 12
Setting VSWR limits using 2G Flexi BTS Site Manager..................... 43
Figure 13
2G Flexi BTS Site Manager connected in remote mode.................... 51
Figure 14
TRX Test window................................................................................56
Figure 15
RF resource allocation........................................................................62
Figure 16
Power budget..................................................................................... 63
Figure 17
ARFCN effects....................................................................................64
Figure 18
Frequency budget...............................................................................65
Figure 19
Smart BCCH recovery when interchangeability is not possible..........66
Figure 20
Smart BCCH recovery when interchangeability is possible................67
Figure 21
TRX power down based on the MCPA priority................................... 76
Figure 22
Multi BCF configuration...................................................................... 79
Figure 23
Synchronized BSS example in Flexi Compact BTS chain..................83
Figure 24
Common BCCH configuration............................................................ 85
Figure 25
Flexi Multiradio BTS in dedicated mode............................................. 86
Figure 26
Flexi Multiradio BTS in concurrent mode............................................87
Figure 27
Basic configuration with RX diversity sharing.....................................87
Figure 28
Feederless rooftop site....................................................................... 89
Figure 29
108 TRX configuration........................................................................90
Figure 30
Single chain of three RF Modules...................................................... 97
Figure 31
Three chains of two RF Modules........................................................97
Figure 32
Three chains of two RRH................................................................... 98
Figure 33
Six RRH distance between System Module and RRH upto 10 km and RRH to RRH 3.0 km (two chains).......................................................98
Figure 34
Three chains of two RF Modules in common BCCH.......................... 98
Figure 35
Three RRHs in once chain and three RF Modules in one chain........ 99
Figure 36
Coverage without and with flexible MCPA.......................................... 99
Figure 37
Power allocation without Flexible MCPA TX Power Pooling............ 100
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8
Figure 38
Power allocation with Flexible MCPA TX Power Pooling................. 101
Figure 39
SDB deployed in one sector............................................................. 104
Figure 40
TRAU bicasting in AMR FR/HR handover........................................108
Figure 41
Dynamic SDCCH allocation.............................................................. 111
Figure 42
SMS-CB DRX Schedule Period........................................................ 113
Figure 43
MS speed detection used for handover decision.............................. 114
Figure 44
Loop principle................................................................................... 126
Figure 45
Packet Abis over Ethernet................................................................ 130
Figure 46
Round trip time/Abis delay measurement.........................................133
Figure 47
QoS Aware Ethernet Switching........................................................ 135
Figure 48
Ethernet-based BTS daisy allocation with BTS integrated Ethernet switch................................................................................................136
Figure 49
Optical and electrical GE connections..............................................137
Figure 50
Optical and electrical GE connections with MWRs...........................137
Figure 51
Packet Abis Transport Media Conversion........................................ 137
Figure 52
Without Composite Multi Site Transmission feature......................... 138
Figure 53
With Composite Multi Site Transmission feature.............................. 139
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Flexi Multiradio 10 Base Station EDGE Feature Descriptions
List of Tables
Issue: 01F
Table 1
Peak data rates for single slot EGPRS ..............................................13
Table 2
Corresponding maximum data rates with different channel coding.... 16
Table 3
Channel and speech codec modes for AMR...................................... 18
Table 4
Logical TRX ID, number of TRXs, and total number of CMST cell nodes..................................................................................................33
Table 5
Number of Logical TRXs and depth of single optical chain (number of RRH per optical chain)....................................................................... 34
Table 6
Software requirements....................................................................... 37
Table 7
Hardware requirements...................................................................... 37
Table 8
Software requirements for different network elements....................... 76
Table 9
Hardware requirements for different network elements......................77
Table 10
Flexi Multiradio RF Module variants................................................... 84
Table 11
Flexi Multiradio RRH Module variants................................................ 84
Table 12
Antenna-optimized configurations...................................................... 88
Table 13
BTS combinations and sync cables....................................................89
Table 14
GSM RF Module chaining configuration.............................................92
Table 15
GSM RRH chaining configuration.......................................................93
Table 16
Common BCCH chaining configuration..............................................94
Table 17
RF Module and RRH chaining configuration...................................... 96
Table 18
TRX power classes limit for MCPA power budget 60 W...................101
Table 19
TRX power classes limit for MCPA power budget 60 W and GSM 52 W...................................................................................................... 102
Table 20
TRX power classes limit for MCPA power budget 60 W and GSM 40W ..........................................................................................................102
Table 21
Configurations supporting RFM........................................................102
Table 22
Configurations supporting RRH........................................................103
Table 23
2 sectors using same pipes configurations....................................... 115
Table 24
Software requirements..................................................................... 125
Table 25
Software requirements..................................................................... 127
Table 26
Number of 16 kbps DAP sub channels used with each CS and MCS.... 128
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Summary of changes
Flexi Multiradio 10 Base Station EDGE Feature Descriptions
Summary of changes Changes between document issues are cumulative. Therefore, the latest document issue contains all changes made to previous issues.
Changes between issues 01E (2015-07- 16) and 01F (2015-08-21) Software requirements table has been added in the following chapters: • •
PDH traffic routing BSS30280 Abis loop protection
Redundant Abis Trunk chapter has been updated with a note.
Changes between issues 01D (2015-05- 06) and 01E (2015-07- 16) BSS10069 Synchronized BSS •
Chapter has been updated.
BSS20371 BSS Site Synchronisation Recovery Improvement •
Chapter has been updated.
BSS11073 Recovery for BSS and Site Synchronisation •
Chapter has been updated.
RG301965 GPS 1PPS+TOD Sync Support •
Chapter has been added.
Changes between issues 01C (2015-03- 26) and 01D (2015-05- 06) BSS21439 Packet Abis Sync. ToP IEEE1588v2 •
10
Chapter has been updated.
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Overview of features in Flexi Multiradio BTS software release GF1
1 Overview of features in Flexi Multiradio BTS software release GF1 Operating and Application SW Nokia RG30(BSS) software consists of Operating Software and Application Software: • •
Operating Software refers to basic functionalities of a product. Application Software refers to optional features.
The RG30(BSS) system features are available in the S16.1 and EX4.2 network element releases.
g
In this document, the RF Modules FXDA, FXDJ, FXEA, FXCA, and FXFA/ FXFB are referred to as 70 W RF Module variants. RF Modules FXCB, FXDB, FXEB, and FXFC are referred to as 90 W RF Module variants.
g
In this document, the RRH Modules FHDA and FHEA are referred to as 2x40 W RRH. FHDB and FHEB variants are referred to as 2x60 W RRH.
g
Feature parity level with EX is only EX4.2 MP1. For more information on the features, see Nokia GSM/EDGE BSS, rel. RG30(BSS), operating documentation. For general guidelines related to licensing, see Licence Management in BSC in the GSM/EDGE BSS operating documentation.
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Data/Voice
Flexi Multiradio 10 Base Station EDGE Feature Descriptions
2 Data/Voice 2.1 BSS20088 Dual Transfer Mode Dual Transfer Mode (DTM) provides mobile users with simultaneous circuit-switched (CS) voice and packet-switched (PS) data services. This means that users can, for example, send and receive e-mail during an ongoing phone call. In dual transfer mode, the mobile station (MS) is simultaneously in dedicated mode and in packet transfer mode, so that the timeslots allocated for each MS are consecutive and within the same frequency.
Benefits With DTM, the operator can expand the service portfolio to offer users enhanced services in a GSM/EDGE network. DTM allows the operator to provide a wide range of services that demand a simultaneous CS and PS connection. Mobile users can use data services, such as file transfer, web browsing, video sharing, and mobile net meeting, during a speech call. This makes it possible to launch services similar to UMTS class A services also in 2G networks. In addition, these services can be used to complement the 3G coverage in places where there is no 3G network coverage.
BTS functionality support The BTS supports DTM through the normal BTS support of CS and PS services.
Interaction with other features DTM supports all full rate speech codecs. The CS speech codec selection for DTM is similar to the selection mechanism used for a plain CS connection. In addition, the DTM PS channels can be multiplexed in a similar way to normal GPRS/EDGE. For more information on Dual Transfer Mode (DTM), see BSS20088: Dual Transfer Mode document.
2.2 BSS9006 General Packet Radio Service (GPRS) General Packet Radio Service GPRS provides packet radio access for GSM mobile stations. By sharing the channels provided by various network elements and transmission systems, the cellular network resources are used more efficiently for data services than with circuit switched data services. All mobile stations share the radio resources in a cell, and use the radio resources only when sending or receiving data. The Channel Coding Unit (CCU) in the BTS performs the channel coding for the following ETSI defined coding schemes: • •
12
Channel Coding Scheme 1 (CS1) 9.05 kbit/s Channel Coding Scheme 2 (CS2) 13.4 kbit/s
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• •
Data/Voice
Channel Coding Scheme 3 (CS3) 15.6 kbit/s Channel Coding Scheme 4 (CS4) 21.4 kbit/s
In packet transfer mode, the mobile station must use the continuous timing advance procedure. This procedure is carried out on all packet data channels (PDCHs). Coding Schemes CS3 and CS4 (BSS11088) is an application software product, and it requires a valid license in the BSC. CS3 and CS4 provide a considerable gain in data rates for GPRS mobile stations not supporting EGPRS (the mandatory RLC header octets are excluded from the data rate values).
Link Adaptation (LA) Flexi BTS supports PCU with GPRS link adaption by providing the measurements for the uplink radio blocks.
Interaction with other features CS3 and CS4 do not fit to one 16kbit/s Abis/PCU channel and require the use of Dynamic Abis Allocation. For more information on General Packet Radio Service (GPRS), see GPRS System Feature Description document.
2.3 BSS10083 Enhanced General Packet Radio Service (MCS-1 - MSC-9) Enhanced General Packet Radio Service (EGPRS) supports high rate packet data services across varying channel conditions. EGPRS is built on top of the packet switched data service, GPRS. As the table below shows, EGPRS supports higher data rates compared to the basic GPRS, using several Modulation and Coding Schemes (MCSs). The speed in radio resources is fixed for Gaussian Minimum Shift Keying (GMSK) and 8 Phase Shift Keying (8PSK), but because the amount of channel coding varies, the user data rate varies depending on the MCS. Table 1
Issue: 01F
Peak data rates for single slot EGPRS
MCS
Modulation
Code Rate
Family
User Rate
MCS-1
GMSK
.53
C
8.8 kbps
MCS-2
GMSK
.66
B
11.2 kbps
MCS-3
GMSK
.80
A
14.8 kbps
MCS-4
GMSK
1
C
17.6 kbps
MCS-5
8PSK
.37
B
22.4 kbps
MCS-6
8PSK
.49
A
29.6 kbps
MCS-7
8PSK
.75
B
44.8 kbps
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Table 1
Peak data rates for single slot EGPRS (Cont.)
MCS
Modulation
Code Rate
Family
User Rate
MCS-8
8PSK
.92
A
54.4 kbps
MCS-9
8PSK
1
A
59.2 kbps
GMSK modulation provides the robust mode for wide area coverage, while 8PSK provides higher data rates. The MCSs are organized into families to allow a re-segmentation of the data block for link adaptation. Since higher protection means lower throughput, the protection that best fits the channel condition is chosen for maximum throughput.
Incremental Redundancy (IR) Incremental Redundancy (IR) is an efficient combination of two techniques: Automatic Repeat ReQuest (ARQ) and Forward Error Correction (FEC). In the ARQ method, when the receiver detects the presence of errors in a received data block, it requests a retransmission of the same data block from the transmitter. The process continues until an uncorrupted copy reaches the destination. The FEC method adds redundant information to the user information at the transmitter, and the receiver uses the information to correct errors caused by disturbances in the radio channel. In the IR scheme (also known as Type II Hybrid ARQ scheme), only a small amount of redundancy is sent first, which yields a high user throughput if the decoding is successful. However, if the decoding fails, a re-transmission takes place according to the ARQ method. Using IR, the re-transmission of the data block is different from the initial transmission. The transmitter sends additional redundancy that is decoded at the destination with the previously received information to allow for error correction. Since the combination includes more information than any individual transmission, the probability of correct reception is increased. The IR mechanism in EGPRS is designed around nine Modulation and Coding Schemes (MCSs). The basic characteristics of each MCS are its fixed data rate and fixed protection level. For each of the MCSs, it is possible to reach the same data rate with the same protection level, but with a different protection scheme.
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Figure 1
Data/Voice
Incremental Redundancy scheme DataBlock
OneMCS P2
P1
P3
Transmitter
P1
P2
P3
1sttransmission
1stre-transmission uponreceptionfailure
2ndre-transmission uponreceptionfailure
P1 ProtectionLevel1
Nodata recovered
P1
P2
Stored
Receiver Nodata recovered
Combination:ProtectionLevelx2
P1
P2
Stored
Stored
P3
Combination:ProtectionLevelx3
There are three protection schemes (P1, P2 and P3) for an MCS, as shown in the figure above. The data block is first protected with the P1 of a certain MCS, and sent over the air to the receiver, which tries to recover the data. If this phase fails, the received P1 is stored in the receiver's memory for future use, and the transmitter sends the data block protected with the P2 of the same MCS. The receiver combines the received P2 with the stored P1 and tries to recover the data from the combination of P1 and P2. This process continues until the data is recovered. If after P3, the data still cannot be recovered, P1 is sent again and combined with the stored P1, P2 and P3 (which reaches a protection level of about four times P1), and so on until the data is recovered.
Link Adaptation (LA) Flexi Multiradio BTS supports PCU with EGPRS link adaption by providing the measurements for the uplink radio blocks.
Interaction with other features EGPRS Modulation and Coding Schemes MCS-1 - MCS-9 require the use of Dynamic Abis Allocation.
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2.4 BSS7003 High Speed Circuit Switched Data and BSS7037 14.4 kbit/s Data Services High Speed Circuit Switched Data uses multiple parallel channels to provide higher data rates for end-user applications, such as the World Wide Web, file transfer and facsimile. The BSS implementation is to reserve a multiple set of basic resources for one high speed data call. The data rate and the number of reserved timeslots vary between one and the defined maximum of the user application. The variable rate is needed for various common procedures, for example for handovers to a new cell if the requested data rate cannot be given immediately. The BSS implementation of HSCSD supports the simultaneous usage of a maximum of four radio timeslots (RTSLs) per HSCSD call. The table below presents the corresponding maximum data rates with different channel coding. Table 2
Corresponding maximum data rates with different channel coding
Number of RTSLs
9.6 kbit/s
14.4 kbit/s
1
9.6 kbit/s
14.4 kbit/s
2
19.2 kbit/s
28.8 kbit/s
3
28.8 kbit/s
43.2 kbit/s
4
38.4 kbit/s
57.6 kbit/s
Both asynchronous and synchronous bearer services and transparent and nontransparent data services are supported. Transparent HSCSD uses fixed data rate throughout the duration of the call, but with non-transparent HSCSD, the data rate can be changed automatically during the call, because of increased traffic for example. The radio interface is either symmetric or asymmetric according to the mobile station (MS) capability. During basic channel allocation, the system tries to keep consecutive timeslots free for multichannel HSCSD connection. If there are not enough appropriate free channels to fulfill the requested data rate, a non-transparent HSCSD connection is started with fewer channels than requested. At least one channel is allocated for a non-transparent HSCSD call request if there are available resources in the cell. By use of the resource upgrade procedure, the data rate of the HSCSD connection can be increased when an appropriate channel is available. In a congested cell, the HSCSD load can be adjusted by BSC parameterization. The resource downgrade procedure is used to lower the HSCSD connection data rate to release radio channels for other connections. If a transparent connection cannot be established in a cell, a directed retry can be attempted.
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BSS7037 14.4 kbit/s GSM Data Services With the 14.4 kbit/s GSM Data Services, the speed of one timeslot increases from 9.6 kbit/s to 14.4kbit/s. The 14.4 kbit/s channel coding has less error correction than 9.6 kbit/s coding. Therefore, there are some areas on the cell edges where using 9.6 kbit/s coding will give a higher data throughput. The figure below shows the results of simulations. Note that for transparent mode the maximum user throughput is 14.4 kbit/s, but in non-transparent mode, the maximum user throughput is 13.2 kbit/s. The maximum throughput is based on the amount of available space in the coding block. Non-transparent data requires space for error checking, but transparent data does not. Figure 2
Data ThroughputRate(kbit/s)
14
Typical data throughputs for 14.4 kbit/s (non-transparent) and 9.6 kbit/s coding (this depends on the NW radio conditions) 14.4
12 10
9.6
8 6 4 2 0 60
65
70
75
80
85
90
95
100
PercentageofCell Area(%)
The Automatic Link Adaptation (ALA) optimizes the data throughput by automatically choosing the channel coding most suitable to the radio conditions and by control of the power levels. The 14.4 kbit/s Data Services can be combined with High Speed Circuit Switched Data (BSS7003). Note that Flexi BTS does not support transparent data handovers because of limitations in fax protocols.
2.5 BSS10004 Adaptive Multi Rate Codec (AMR) Adaptive Multi Rate Codec provides significantly better speech quality by: • •
using better source coding algorithms that give better subjective speech quality for the same link capacity adaptively adjusting ratio of bits used for speech coding and channel coding to always provide best subjective speech quality according to current radio conditions.
With AMR it is possible to increase speech capacity by using HR mode and still maintain the quality of current FR calls. It consists of an adaptive algorithm for codec changes and 8 different speech codecs (14 codec modes) listed in the table below.
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Table 3
Channel and speech codec modes for AMR
Channel mode
Channel codec mode
Source coding bitrate, speech
Net bit-rate, in-band channel
Channel coding bitrate, speech
Channel coding bitrate, in-band
TCH/FR
CH0-FS
12.20 kbit/s (GSMEFR)
0.10 kbit/s
10.20 kbit/s
0.30 kbit/s
0.10 kbit/s
12.20 kbit/s
0.30 kbit/s
0.10 kbit/s
14.45 kbit/s
0.30 kbit/s
0.10 kbit/s
15.00 kbit/s
0.30 kbit/s
0.10 kbit/s
15.70 kbit/s
0.30 kbit/s
0.10 kbit/s
16.50 kbit/s
0.30 kbit/s
0.10 kbit/s
17.25 kbit/s
0.30 kbit/s
0.10 kbit/s
17.65 kbit/s
0.30 kbit/s
CH1-FS CH2-FS CH3-FS CH4-FS CH5-FS CH6-FS CH7-FS
10.20 kbit/s 7.95 kbit/s 7.40 kbit/s (IS-641) 6.70 kbit/s 5.90 kbit/s 5.15 kbit/s 4.75 kbit/s
TCH/HR
CH8-HS
7.95 kbit/s (*)
0.10 kbit/s
3.25 kbit/s
0.10 kbit/s
CH9-HS
7.40 kbit/s (IS-641)
0.10 kbit/s
3.80 kbit/s
0.10 kbit/s
0.10 kbit/s
4.50 kbit/s
0.10 kbit/s
0.10 kbit/s
5.30 kbit/s
0.10 kbit/s
0.10 kbit/s
6.05 kbit/s
0.10 kbit/s
0.10 kbit/s
6.45 kbit/s
0.10 kbit/s
CH10-HS CH11-HS CH12-HS CH13-HS
6.70 kbit/s 5.90 kbit/s 5.15 kbit/s 4.75 kbit/s
(*) Not supported, requires 16 kbit/s TRAU.
Codec mode adaptation for AMR is based on received channel quality estimation in both the mobile station (MS) and the BTS. The BTS and MS inform and request of codec used/to be used by in-band signaling. For more information on Adaptive Multi Rate Codec, see BSS10004 and BSS6071: Enhanced Speech Codecs: AMR and EFR document.
2.6 BSS7005 Intelligent Frequency Hopping and BSS6114 Intelligent Underlay-Overlay With Intelligent Frequency Hopping and Intelligent Underlay-Overlay, it is possible to reuse frequencies more intensively, and therefore achieve a higher radio network capacity. With Intelligent Frequency Hopping, it is also possible to avoid frequency dependent fading on the radio path. When Intelligent Frequency Hopping is in use, the operator can use Intelligent UnderlayOverlay simultaneously with frequency hopping in the same cell. Either baseband (BB) or radio frequency (RF) hopping can be used.
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The different interference characteristics of the regular and super-reuse layers in Intelligent Underlay-Overlay require that the network plan for frequency hopping is constructed separately for each layer. Intelligent Frequency Hopping enables the use of separate Mobile Allocation Frequency Lists of radio frequency hopping for the layers of an Intelligent Underlay-Overlay cell. Baseband hopping is implemented by treating the regular layer as a normal cell and the super-reuse layer as a new hopping group. The operator can set the regular and super-reuse layers in Intelligent Underlay-Overlay individually to hopping. For more information on Intelligent Underlay-Overlay, see Intelligent Underlay-Overlay document.
2.7 BSS20960 Wideband AMR and BSS21118 TFO for AMR These features introduce wideband AMR coding as specified by 3GPP and ITU-T. Wideband AMR is based on a family of new speech codecs. It is designed to achieve improvements in speech quality. The sampling rate of WB AMR speech codec is increased to 16 kHz which allows the bandwidth of the signal encoded to be extended to cover range from 50 to 7000 Hz. Wideband AMR requires end to end tandem free operation support. For more information on these features, see the document BSS20960: Wideband AMR and BSS21118: AMR TFO.
2.8 Long Reach TCH TSL A new RTSL type, Long Reach TSL, is used temporarily for incoming external handovers (from 2G or 3G) in order to allow the BTS to determine the cell area (normal or extended) where the mobile is actually located. The BTS informs the correct area to the BSC which starts an intra-cell handover to this area.
2.9 BSS101482 Extended Cell functionalities for Flexi Multiradio BTS Flexi Multiradio BTS supports extended cell features from EX4.1 onwards. The BSC allows the user to configure these features for use in Flexi Multiradio BTS. The feature has no separate license and the existing Flexi EDGE license applies for Flexi Multiradio BTS. Benefits Extended Cell Range increases the cell radius to about 105 km, which means that this kind of extended cell covers an area that is much larger than an ordinary cell, thereby reducing CAPEX. The feature provides continuous support for upgrading the Flexi Multiradio BTS with EX4.1 or later versions.
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BSS20882 Extended Cell Range for CS The cell radius of an ordinary cell is 35 kilometers. Extended Cell Range increases the cell radius to about 70 km. The implementation is based on a one-BCCH and two-TRX solution. Timing of the TRXs that serve the extended coverage area is delayed so that they can serve the area beyond 35 kilometers. The extended coverage area is served with different TRXs than the normal coverage area and the TRXs so configured are referred to as Extended TRXs (E-TRX).
BSS20094 Extended Cell support for GPRS/EDGE Extended cell for GPRS/EDGE has been built on top of the extended cell function. This means that the same method is used for creating the normal and extended service areas, and the same parameters are used for dimensioning the cell for both PS and CS services. The two service areas are part of the same cell and both areas are served by the same BCCH. In practice this means that MS movement between the service areas is handled as intra-cell reallocation instead of cell re-selection. Only the BCCH BTS of an extended cell may serve the extended service area, that is, the TRXs serving the extended service area must be accommodated by the BCCH BTS. The minimum extended cell configuration includes two TRXs – one for the extended service area and one for the normal service area – but multiple TRXs may be used in both service areas. Implementation The extended cell implementation is based on one-BCCH and two-TRX solution. Different TRXs serve the normal and the extended area. The TRX, which serves the normal area, is normally configured with the BCCH/SDCCH and TCHs. The timing of the receiver of the TRX which serves the extended area (E-TRX) has been delayed so that it can serve the area beyond 35 kilometres. The timeslot 0 of E-TRX is tuned to the BCCH frequency in order to get RACH-bursts from the extended area. The timing of transmitters is the same in both TRX and E-TRX. If more capacity is required either in the normal area or extended area, more TRXs can be added to serve those areas. • •
The Extended Cell Range for Flexi EDGE BTS is supported for all Flexi frequency bands. MHA units should be used in the Flexi EDGE BTS configuration to ensure transmitted signal strength can reach the maximum range.
Interaction with other features The following features cannot be used simultaneously with the Extended Cell Range for Flexi EDGE BTS: • • • • • •
20
Baseband hopping RF hopping cannot be used in extended area TRXs (RF hopping can be used in normal area non-BCCH TRX(s), if present) Antenna hopping Intelligent Underlay Overlay (IUO) Dynamic Frequency Channel Allocation (DFCA) TRX Test: TRX Test cannot be commanded for a TRX configured to cover the extended outer area
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Flexi Multiradio 10 Base Station EDGE Feature Descriptions
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Benefits for the Operator The extended cell feature is best suited for applications in coastal areas, rural areas and corresponding ones where coverage exceeds typical GSM maximum cell size of 35 km. Capex and Opex savings by enlarging cell areas and reducing number of radio sites improved end user experience by having wider coverage Extended cell for GPRS/EDGE feature is best suited for configurations in coastal and rural areas where coverage exceeds typical GSM maximum cell size of 35 km.
BSS21270 105 km Extended Cell and BSS21277 105 km Extended Cell for GPRS/EDGE BSS21277 and BSS21270 are optional features and those can be used with FlexiMultiradio BTS to increase the cell radius to about 105 km. The cell radius in a normal cell is 35 km, and the cell radius of the extended cell is 70 km. The cell with a 105 km radius is referred to as a super-extended cell.105 km extended cell features have been built on top of the extended cell function. This feature expands the maximum extended cell radius to 105 km by allowing TRX reception to be delayed further (up to 80% of a TSL duration) in relation to TRX transmission. The TRXs so configured are referred to as super extended TRXs (STRXs). This feature concerns only CS services. Interaction with other features The following features cannot be used simultaneously with features BSS21277 and BSS21270: • • • • • •
Baseband hopping RF hopping cannot be used in extended/super extended are TRXs (RF hopping can be used in normal area non-BCCH TRX(s), if present) Antenna hopping Intelligent Underlay Overlay (IUO) Dynamic Frequency Channel Allocation (DFCA) TRX Test: TRX Test cannot be commanded for a TRX configured to cover the extended/super extended outer area
Benefits for the Operator Capex and Opex savings by enlarging cell areas and reducing number of radio sites improved end user experience by having wider coverage Extended cell for GPRS/EDGE feature is best suited for configurations in coastal and rural areas where coverage exceeds typical GSM maximum cell size of 35 km.
BSS21274 Long Reach TSL (2G BTS) Normally the BSC attempts to allocate incoming external handovers always to E-TRXs in extended cells, however, it is possible that the mobile is actually located in the normal coverage area of the target cell. In this case the handover would fail. The long reach timeslot feature addresses this scenario. Requirement The features are supported with RG20(BSS) EP1
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2.10 BSS21388 Random Fill Bits This new feature provides an additional security enhancement for the generally employed A5/1 ciphering solution as well as the A5/3 security mechanism and mitigates the risks associated with a potential 'cracking' of the standard A5/1 mechanism, which employs a fixed pattern filling bits sequence. Benefits for the Operator Whilst the A5/3 ciphering solution provides the required level of security against the 'cracking' of the standard A5/1 ciphering mechanism, near-full penetration of supporting handsets is not available currently in today's networks. Consequently, this feature provides another essential enhancement for the existing A5/1 ciphering mechanism in cases where the A5/3 solution cannot be employed. This feature may also be used to enhance the A5/3 ciphering mechanism and thus security. Functional Description In general, the A5/3 ciphering solution has been released and ultimately provides the required level of security against this problem. However, since A5/3 capable handsets currently do not represent the majority in general field deployments, this enhancement to the A5/1 solution mitigates the immediate issue for Operators. The solution itself has arisen from fears concerning the co-ordinated efforts into the real-time 'cracking' of the generally employed A5/1 ciphering security mechanism. If a frame contains a length indicator with value less than N201, the frame contains fill bits. Currently, the fixed sequence '00101011' is employed for these fill bits. With this new feature, excluding the first octet which still uses the fill bits '00101011', each subsequent fill bit shall be set to a random value when sent by the network for either the A5/1 or A5/3 encryption mechanism. A new activation parameter (acting at the cell level) is introduced. The default value is that the feature is not activated. This feature may be used in combination with BSS21389 or separately, as required. Requirements • • •
The feature is supported with RG20(BSS) EP1 The feature is supported via NetAct release OSS5.2 MP1 The feature (and licence key for) BSS21389, A5/1 Cipher Enhancement - SDCCH HO. The features may be activated independently of one another.
2.11 BSS21309 OSC Half Rate with SAIC MS “Orthogonal subchannel (OSC)” is a feature that increases the radio channel capacity for voice calls in GSM networks. This is provided by adopting quadrature phase shift keying (QPSK) in downlink and orthogonal subchannels in uplink. These two key techniques linked with adaptive multi rate (AMR) make it possible to serve two users that support single antenna interference cancellation method (SAIC) simultaneously, in the single radio traffic channel. The increase in network capacity depends on the radio conditions. The feature “BSS21309 OSC Half Rate with SAIC MS” implements the OSC feature for Half Rate traffic channels. With this feature, four users can share the same radio timeslot with SAIC and AMR support from the mobile station. When OSC Half Rate with SAIC MS is used, an increased Abis transmission capacity is required because OSC Half Rate
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calls are multiplexed into one Half Rate traffic channel (TCH/H). The increased Abis transmission capacity is provided by circuit switched dynamic Abis pools (CSDAPs) or packet Abis. OSC Half Rate with SAIC MS is an application software feature controlled by licensing. For detailed description of this feature, see BSS21309: OSC Half Rate with SAIC MS Feature Description document. This feature provides the following benefits: • •
• • • •
The feature is applicable with existing GSM SAIC handsets, thus providing an immediate gain with just a software upgrade in the GSM radio network It increases the capacity for voice and releases capacity for data traffic without requiring new TRXs or related hardware. This reduces the number of TRXs required to realize a specific capacity or spectral efficiency The increased capacity per TRX reduces the energy consumption per user. This reduces the energy consumption required per Erlang significantly It avoids the need to add new sites, as it maintains the coverage area in capacity extensions The increased capacity per TRX effectively reduces site density through reduced combining losses When another radio technology needs to share the same site, antennas or input ports of combiners may be released by the introduction of OSC Half Rate with SAIC MS
Interaction with other features The “BSS21309 OSC Half Rate with SAIC MS” feature has the following limitations with these features: •
•
• • •
•
4-way uplink diversity The BSC does not apply DHR multiplexing in a TRX that has 4-way uplink diversity (4UD) feature in use. Dynamic Frequency and Channel Allocation The BSC does not support Double Half Rate with SAIC MS feature in the TRXs that apply the Dynamic Frequency and Channel Allocation (DFCA) feature. Extended Cell Range DHR multiplexing is not applied in the TRXs of the extended coverage area. Super Extended Cell Range OSC is not supported in the TRXs of the Super Extended coverage area. Intelligent Downlink Diversity The BSC does not apply DHR multiplexing in a TRX that has Intelligent Downlink Diversity (IDD) feature in use. Rx diversity Use of Double Half Rate requires that the Rx diversity feature is also in use.
Recommendation Some handset types may not perform equally good with few of the available training sequence pairs. If OSC capacity is critical for a particular cell, then TSC pairs (1, 7) and (5, 6) should be avoided to maximize the cell capacity with OSC. Requirements •
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• • •
Flexi EDGE BTS EX4.0, Flexi Multiradio BTS EX4.1 or Flexi Multiradio 10 BTS GF1.0 NetAct OSS5.2 CD SET 3 MS Capable of SAIC and AMR
2.12 BSS21534 OSC Full Rate with SAIC MS The feature, BSS21534: OSC Full Rate with SAIC MS (also referred as Double Full Rate or DFR) serves two AMR FR calls on SAIC capable handsets simultaneously on single full rate traffic channel in a similar way as the feature, Double Half Rate with SAIC MS (DHR) serves two AMR HR calls on SAIC capable handsets simultaneously on single half rate traffic channel. OSC Full Rate is an optional feature controlled by using an On-Off license and a capacity license. BSS21534 OSC Full Rate with SAIC MS (Activation License) is an ON/OFF license and provides an initial capacity of 100 simultaneous DFR Pairs. BSS402011 OSC Full Rate Capacity License provides additional capacity in blocks of 100 DFR Pairs. In a configuration, where a BTS has the OSC Full Rate feature enabled the BSC allows unlocking of the BTS in question only if the OSC Full Rate with SAIC MS feature’s state is ON. The use of OSC Full Rate feature is controlled with a BTS object parameter in the BSS RNW Configuration Database. The BSC requires that a BTS object is in the locked state in order to allow enabling or disabling OSC Full Rate in the BTS. The enabling of OSC Full Rate feature results in modifying the parameter Limit for Triggering OSC DFR Multiplexing from 0 to a value greater than 0. The disabling of OSC Full Rate feature means modifying the parameter from a value greater than 0 to 0. Having the parameter on BTS level allows the BTS specific control of the feature in segment configuration where the operator can apply different policies for different layers of a segment. Recommendation Some handset types may not perform equally good with few of the available training sequence pairs. If OSC capacity is critical for a particular cell, then TSC pairs (1, 7) and (5, 6) should be avoided to maximize the cell capacity with OSC. Requirements • • • •
BSC S15 EP1.2 Flexi EDGE BTS EX4.1, Flexi Multiradio BTS EX4.1 or Flexi Multiradio 10 BTS GF1.0 NetAct OSS5.2 CD SET 3 MS Capable of SAIC and AMR
2.13 BSS21325 8k TRAU for OSC AMR FR The feature, BSS21325: 8k TRAU for OSC AMR FR allows two AMR FR calls multiplexed as OSC using fixed transmission capacity allocated for a single Radio TSL in legacy Abis.
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Two OSC AMR FR calls can be supported within legacy Abis transmission allocated for a single radio timeslot (that is 2*8kbit/s Abis timeslot) when 8kbit/s TRAU frames are used on Abis. When 8K TRAU for OSC AMR FR feature is enabled AMR codecs are restricted up to 7.4K within the codecs used in the active codec set (ACS). The OSC-0 call is supported in the first half of the Abis timeslot and the OSC-1 call is supported in the second half of the Abis timeslot. The feature, BSS21325: 8k TRAU for OSC AMR FR is optional with ON/OFF type license. The 8k TRAU for OSC AMR FR can be activated independently from OSC Full Rate with SAIC MS (BSS21534) and Circuit Switched Dynamic Abis Pool (BSS30385) features. The BSC specific ON/OFF license controls the availability of the 8k TRAU for OSC AMR FR feature. The usage of this feature is controlled with a new BTS level parameter, 8k TRAU for DFR Enabled. This parameter enables the DFR multiplexing in 8k TRAU mode. It also defines the preference in selection between CSDAP and 8k TRAU mode for DFR calls. Requirements • •
BSC S15 EP1.2 Flexi EDGE BTS EX4.1, Flexi Multiradio BTS EX4.1 or Flexi Multiradio 10 BTS GF1.0
2.14 BSS21313 OSC support for VAMOS handsets Voice services over adaptive multi-user channels on one slot (VAMOS) is a 3GPP standardized feature, which allows the multiplexing of two users simultaneously on the same physical resource in the circuit switched mode both in downlink and in uplink, using the same timeslot number and TDMA frame number. OSC is Nokia proprietary feature for VAMOS. OSC support for VAMOS Handsets feature is extension to OSC in which the BSC supports the Training Sequence Code Set 2 (TSC Set2) and VAMOS mode indication functionality. The two classes of standardized VAMOS handsets are: • •
VAMOS 1 supporting new training sequences, called TSC set2, and having DL SAIC (or DARP phase I) receiver. VAMOS 2 supporting new training sequences, called TSC set2, and having advanced receiver architecture than that of VAMOS 1.
The feature ‘BSS21313 OSC support for VAMOS handsets’ implements support for new training sequences (TSC set2) for handsets indicating VAMOS capability. This feature is an enhancement of basic OSC features BSS21309 Orthogonal subchannel with SAIC MS and BSS21534 OSC Full Rate to extend support for new VAMOS 1 and VAMOS 2 handsets. This feature is controlled by an ON/OFF license. Implementation TSC set2 is selected for VAMOS capable calls even in normal non-paired TCH allocation to increase the pairing probability for SAIC-VAMOS pairs. In case of SAIC-VAMOS pairs, if the first multiplexing candidate is VAMOS capable and uses TSC set1 and second multiplexing candidate is SAIC capable which doesn't support TSC set2, the pairing of these mobiles is not possible since TSC of first candidate cannot be changed during
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multiplexing. The VAMOS-SAIC pairing where first multiplexing candidate is VAMOS capable is possible only if this VAMOS capable candidate is using TSC set2. When OSC pair is selected: • •
First candidate call maintains the same TRX, TSL and OSC subchannel, and currently used TSC code. Second candidate call is moved to the target radio channel (to other OSC subchannel) with intra cell handover, and its TSC code is set according to the following rules: – –
•
TSC (set1, set1) in case of legacy SAIC-legacy SAIC OSC pair TSC (set1, set2) or TSC (set2, set1) in case at least one handset is VAMOS capable. Handset using TSC set2 has to be VAMOS capable. To support OSC for VAMOS, the OSC multiplexing has been enhanced to take into account the different types of handsets in OSC pairing and TSC selection.
First candidate selection and second candidate selection shall consider not only legacy SAIC handsets but also VAMOS 1 and VAMOS 2 handsets can be included.
For more details, please refer the below feature description documents: • • •
BSS21309 Double Half Rate with SAIC MS BSS21534 OSC Full Rate with SAIC MS BSS21537 AQPSK with VAMOS 2 Handsets
Benefits •
•
‘OSC support for VAMOS handsets’ feature provides better performance in UL and DL for VAMOS pairs due to the usage of new training sequence codes (TSC set2), as new TSCs have low cross-correlation with legacy TSCs. VAMOS 2 capable mobiles have better performance in DL, as they have more advanced receiver than SAIC.
Requirements • • • •
BSC S16 Flexi Multiradio BTS EX5.1 or Flexi Multiradio 10 BTS GF1.0 NetAct OSS5.4 MS Capable of VAMOS (VAMOS 1 or VAMOS 2)
2.15 BSS21537 AQPSK with VAMOS 2 Handsets 'AQPSK with VAMOS 2 Handsets' feature extends Orthogonal Subchannel (OSC) support for non-SAIC handsets when paired with VAMOS 2 capable handsets with the support of AQPSK modulation in downlink. This feature includes the support of DL AQPSK modulation creating quaternary constellation using fixed static alpha parameter. Alpha parameter gives the gain obtained on higher power subchannel compared to equally powered (QPSK modulated) subchannels and is dependent on used phase rotation. For more details see the AQPSK constellation figure. The feature BSS21537: AQPSK with VAMOS 2 Handsets is controlled by an ON/OFF license.
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AQPSK modulation together with advanced receiver performance of VAMOS 2 handset allows BTS to use OSC sub channel specific power for a non-SAIC – VAMOS 2 pair. BTS and TRX needs to support AQPSK modulation before BSC can multiplex a nonSAIC handset with a VAMOS 2 handset. The non-SAIC handset of the OSC pair gets downlink boost when it is allocated to the higher power sub channel whereas VAMOS 2 handset of the same OSC pair can survive in the lower power sub channel because of its advanced receiver performance. AQPSK modulation is applied when non-SAIC and VAMOS 2 handset are multiplexed and when the pair is demultiplexed, modulation is changed to GMSK for the remaining connection. DL AQPSK modulation creates quaternary constellation using fixed static alpha parameter. Alpha parameter gives the gain obtained on higher power subchannel compared to equally powered (QPSK modulated) subchannels. Alpha value = 1.3 is the only value supported by this feature. VAMOS 2 mobiles are supposed to be based on architectures that would enable better detection of the subchannel signal at lower subchannel power imbalance ratios (SCPIRs). AQPSK modulation creates quaternary constellation using phase rotation f, as shown in below figure. Figure 3
AQPSK constellation
ORTHOGONAL SUB CHANNEL ACTIVATION FAILURE Alarm BSC raises ORTHOGONAL SUB CHANNEL ACTIVATION FAILURE alarm for the BTS when consecutive OSC channel activation failures take place during multiplexing in a TRX in OSC DHR and OSC DFR features. BSC uses the same procedure and the same rules when AQPSK modulation is involved in multiplexing. A supplementary information field is added to the alarm to display AQPSK modulation involvement in failed consecutive OSC multiplexing attempts. The supplementary information field is set when AQPSK modulation has been involved at least in one of the failed consecutive OSC multiplexing attempts that trigger the OSC channel activation failure alarm. AQPSK modulation information in the alarm provides a way to see if AQPSK modulation increases consecutive OSC channel activation failures. Benefits
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•
OSC support can be provided to non-SAIC handsets to increase the network voice capacity.
Requirements • • • •
BSC S16 or later Flexi Multiradio BTS EX5.1 or Flexi Multiradio 10 BTS GF1.0 NetAct OSS5.4 CD Set 2 or later MS Capable of VAMOS 2, AMR and Non-SAIC AMR
2.16 RG301666 EGPRS Downlink Power Control The EGPRS Downlink (DL) Power Control feature helps in controlling the downlink transmit power on EGPRS timeslots and decreasing the interference that is caused due to progressive introduction of packet switched services in GSM networks. DL power control initially starts from maximum power and adjusts power so that the target BEP or C/I levels can be maintained. The power control in DL transmission is done on a block-by-block basis depending on the receiver’s channel conditions. If a Mobile Station (MS) is in good radio conditions, the DL transmit power for the MS can be reduced. If the MS is in bad radio conditions, then the DL transmit power for this MS can be increased. This not only reduces interference in the radio network, but also reduces BTS Power consumption.
g
DL power ctrl can only be applied when dedicated PS data blocks are sent to exactly one MS. In the existing Abis L1 interface the DL PCU (master) data frames contain a Downlink Power Control field which indicates the DL power level to BTS. Currently, PCU sets this field based on PMAX (= maximum power level on the TRX) and the value is not changed unless the parameter value is changed by the operator. With the Downlink Power Control for EGPRS DL Power Control feature, PCU controls the DL transmit power with the same field but now the field value is changed on a blockby-block basis based on a pre-defined algorithm using which the PCU sets the DL power level for each DL RLC block. The BTS sets the DL transmit power on a block-by-block basis based on the Downlink Power Control field. The key parameters for the Downlink Power Control field for the EGPRS DL Power Control feature are: • • • •
Initial DL power (-4 dB) Minimum DL Power (Pmax-8 dB) Target BEP for EGPRS (29) Target C/I for GPRS (14 dB)
Benefits The EGPRS DL Power Control feature provides the following benefits to the operator: • •
28
It reduces transmit power, which in turn helps in reducing the interference in the network, and hence the mobiles experience better radio conditions. It helps in reducing BTS power consumption.
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It maintains voice quality when the data usage increases.
2.17 BSS21542 OSC Capability Test for Handsets 'OSC Capability Test for Handsets' feature increases and improves utilization of BSS21309: OSC Half Rate with SAIC MS and BSS21534: OSC Full Rate with SAIC MS features available in the BSC. Handsets that do not indicate Single Antenna Interference Cancellation (SAIC) support to the network are tested with a momentary Quadrature Phase-Shift Keying (QPSK) transmission. Handsets that clear the test are regarded as OSC capable and are candidates for OSC multiplexing. This way the utilization of OSC is increased in the network. OSC reliability is checked to ensure OSC capability of handsets. If the DL RX quality of a handset decreases drastically after OSC multiplexing then the handset is regarded as non OSC capable by the BSC. This improves the quality of the network. OSC Capability Test for Handsets is an optional feature that is controlled with BSC license key, ON/OFF. Test for Handsets is as below: • • •
Handset Selection OSC Capability Test RX Quality Report Generation and Inference
Figure 4
OSC Capability Test for Handsets
MS
BTS
BSC CHANNEL ACTIVATION (OSC test information)
Boosted speech over QPSK
Measurement report Measurement Result (OSC test IE)
Handset Selection BSC selects handsets that have to undergo OSC Capability Testing based on following criteria: • • • • •
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DARP capability not indicated in MS Classmark 3 Revision level indicated in MS Classmark 1 and 2 is not GSM phase 1 AMR codec has been selected for the TCH to be activated Emergency calls are not selected Handsets that are already tested are not selected
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•
Handsets whose channel activation is related to OSC multiplexing are not selected
BSC’s decision to test a handset is informed to BTS in Channel Activation message OSC Capability Test BTS decides when to start the OSC Capability Test. The decision is based on DL RX quality reports received from the MS. If the reported downlink RX quality is equal to or better than a new DL RX quality threshold for OSC capability test parameter, the test is initiated. BTS sends boosted QPSK over test period to probe handset’s OSC capability. Test Report Generation and Inference BSC determines handset OSC capability by comparing DL Rx Quality values from test period to DL Rx Quality values prior to the test period. If DL Rx Quality remains acceptable during the test period then BSC regards the handset as OSC capable. If DL Rx Quality degrades to unacceptable level or BSC cannot complete the comparison then it regards the handset as OSC incapable.BSC maintains handset OSC capability test result until the end of the call or until the handset is handed over to other BSC. Detecting and Handling of MS with Faulty SAIC Indicator Handsets that indicate SAIC support to the network are regarded as non OSC capable by the BSC if, the DL RX quality of these handsets decreases drastically right after OSC multiplexing. In such a scenario, BSC does not select the handset again for multiplexing for the remaining duration of the call. Benefits • •
The feature increases network capacity by increasing OSC utilization The feature improves network quality and reduces call drop rate by identifying SAIC capable MSs that cannot survive in OSC mode
Requirements • • • •
BSC S16 Flexi Multiradio BTS EX5.1 or Flexi Multiradio 10 BTS GF1.0 NetAct OSS5.4 CD Set 2 MS capable of SAIC but not reporting and capable of non-OSC but SAIC reporting
2.18 RG602124 Composite Multi Site Transmission In Composite Multi Site Transmission feature, antennas at different locations are merged into one single logical cell, or composite cell, which helps in reducing the inter-cell handover. The BTS is connected to multiple antennas (nodes) that are not co-located. A maximum of six nodes are allowed in one BTS. If the transmitting and receiving antennas are chosen correctly for every connection, the coverage in the cell becomes a union of coverage areas of individual antennas. This way, the coverage can be improved without increasing the number of cells and the number of handovers. In order to minimize inter cell handovers, the non-co-located antennas are merged into a single cell. The feature reduces inter-cell handovers in, for example, multi-floor sites thereby improving network performance.
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Data/Voice
Note that maximum of 12 nodes are allowed in GF. The user can travel from one node to another inside the logical cell without a handover. Inter-cell handover is needed only when moving from one logical cell to another. When a handover occurs inside a logical cell, the TRX id and TSL remain the same but the composite node id changes. In order to avoid an accumulation of interference for CS Channels, a single active transceiver node is selected - that with the best Uplink signal from the (up to) six nodes that are available. Additionally, one node for receiving (Uplink Diversity) is also selected. The BCCH Channel and PS Services are broadcasted through all nodes in the Downlink. Figure 5
Floor 7
Composite cell concept in multi-floor solution
Cell 7
Cell 2 HO
HO Floor 6
Cell 6
Cell 1
Node 6
HO Floor 5
Cell 5
Cell 1
Node 5
HO Floor 4
Cell 4
Cell 1
Node 4
HO Floor 3
Cell 3
Floor 2
Cell 2
Floor 1
Cell 1
Cell 1
Node 3
Cell 1
Node 2
Cell 1
Node 1
HO
GSM SM
HO
a) Without Composite Multi Site Transmission
b) With Composite Multi Site Transmission
For call set up and handovers, BTS informs the BSC about the antennas using Channel Required and Measurement Result messages. BSC provides the details received through these messages back to BTS in Channel Activation message for relaying them to target cell BTS in call setup and in BSC internal handovers when the feature is enabled. The BTS uses this information for correct mobility management inside composite cell Composite Multi Site Transmission feature is controlled with TRX based capacity license. For Flexi Multiradio 10 BTS enhanced CMST feature, see RG301980 CMST Support with FSM3. Benefits The Composite Multi Site Transmission feature provides the following benefits to operators: • •
It reduces the number of required cells since the composite cell has same area as several individual cells. It improves the network performance due to less inter-cell handovers.
Restrictions The following features can not be used with this feature:
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• • • •
• • • • • • • • •
OSC Half Rate (BSS21309) and OSC Full Rate (BSS21534) DFCA (BSS11052) and DFCA Support for OSC (BSS21391) MCPA Tx Power Pooling (BSS21507) Intelligent Underlay Overlay (BSS04016), Handover Support for Coverage Enhancement (BSS07064), and Enhanced Coverage by Frequency Hopping (BSS08037) Extended Cell (BSS101482) and super extended cell (BSS21270) Long Reach TSL (BSS21274) Multi Operator BSS (BSS21213) RF sharing GSM-LTE (BSS21520) RF sharing GSM-WCDMA Satellite Abis (BSS5850) Preferred BCCH mark is not recommended to use since BTS will internally control with BTS_ALARM that BCCH is located to the TRX which is the best possible. Multi BCF (BSS10046) configuration is not allowed since BCF where Composited Multi Site Transmission is activated can contain only one BTS object configuration. RX Diversity shall be enabled on segment where CMST is enabled (that is, no single antenna support
2.19 RG602125 High Speed Rail Handover In the feature RG602124 Composited Multi Site Transmission, up to six spatially distributed Remote Radio Heads (RRH) are linked and synchronized into a single cell. This reduces the number of handovers in the coverage area of Composited Multi Site cell.. RG602125 High Speed Rail Handover is an enhancement of Composite Multi Site Transmission feature, and provides more reliable mobility management in places where existing handover features may not provide fast enough HO decisions for cell change. Figure 6
CMST in railway environment
This feature provides a fast handover (HO) decision for a mobile station (MS) that is travelling on a high speed train where the uplink signal level degrades rapidly. It executes handover to one pre-defined GSM adjacent cell when the serving composite cell coverage ends. It is possible to define one GSM target adjacent cell for each of the composited multi site cell nodes. High Speed Rail handover to a pre-defined adjacent
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cell is performed without any radio link measurements of the pre-defined adjacent cell. Composite Multi Site Transmission feature is needed as a base to provide composite cell structure. If High Speed Rail Handover is active, then RSSI part of Enhancement on VSWR and RSSI feature is not supported. The feature is controlled with TRX based capacity license. For Flexi Multiradio 10 BTS enhanced CMST feature, see RG301980 CMST Support with FSM3. Benefits It provides fast handover decision towards a pre-defined adjacent cell. It provides successful mobility management by providing fast and reliable handover. It provides the MS with a speed of upto 450 km/hr on high speed train.
• • •
Restrictions In an HSR site when optical cable length between ESMx and FHxX is >10 km, Uplink samples are not be received by DSP SW for TRX defined on FHxX(connected with >10KM) but Downlink Transmission works fine from all the Nodes. This impacts the TRX test and CS call.
•
Requirements BSC S16 Flexi Multiradio BTS EX5 or Flexi Multiradio 10 BTS GF1.0 NetAct OSS5.4 CD Set 2
• • •
2.19.1 CMST configuration restrictions(BSC): This section provides CMST configuration restrictions in BSC. All the neighbors equipped for a CMST cell should be configured as type ASYNCHRONOUS.
•
g
• •
A CMST configuration in a collocated BTS should be avoided. In case of a collocated BTSs, the CMST and non-CMST cells should not be defined as SYNCHRONIZE neighbors otherwise this would result in Handover failure and other unpredictable behavior.
Table 4
Logical TRX ID, number of TRXs, and total number of CMST cell nodes
CMST Nodes
Abis TRX ID
1
1
Supported Logical TRX_id = any of (1,4,7,…,31,34); otherwise 7600 alarm at start-up
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2
3
4
5
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7
8
9
10
11
12
Supported Logical trx_id = any of (1,7,….31); otherwise 7600 alarm at startup
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Flexi Multiradio 10 Base Station EDGE Feature Descriptions
Table 4
Logical TRX ID, number of TRXs, and total number of CMST cell nodes (Cont.)
CMST Nodes
Abis TRX ID
1
2
3
4
5
6
7
8
9
10
11
12
13 19 25 31 4
Invalid, disable any invalid TRXs, with 7606 alarm (BB resource not avalable) if a BCF is already operational
10 16 22 28 34
Table 5
Number of Logical TRXs and depth of single optical chain (number of RRH per optical chain)
RRH per RP3-01 link
Abis TRX
1
2
3
4
5
6
1 2 3 4 5 6
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Number of Logical TRXs and depth of single optical chain (number of RRH per optical chain) (Cont.)
RRH per RP3-01 link
Abis TRX
1
2
3
4
5
6
7 8
*
9
*
*
10
*
*
11
*
*
*
*
12
*
* - 7600 (at startup) or 7606 (run-time) RP3-01 UL bandwidth overload alarm
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Flexi Multiradio 10 Base Station EDGE Feature Descriptions
3 Interworking 3.1 BSS10101 GSM-WCDMA Interworking In order for an operator to provide seamless coverage in areas where WCDMA is not available, such as rural areas, inter-system handovers are introduced. This feature facilitates handovers between GSM BSS and WCDMA RAN. When the WCDMA and GSM networks overlap, also an inter-system handover from GSM to WCDMA can be made to release traffic load in the GSM system. Flexi Multiradio BTS supports this feature as a GSM EDGE Base Station.
3.2 BSS11086 Support for Enhanced Measurement Report Support for Enhanced Measurement Report (EMR) provides the system with enhanced serving and neighbor cell measurements. This is achieved by requesting the mobile station (MS) to use the EMR for reporting downlink measurements. Enhanced Measurement Report also provides the system with information such as Downlink Frame Erasure Rate (DL FER), the usage of bit error probability (BEP) instead of RX Quality during the DTX frames, and the support for reporting WCDMA RAN neighbor cells. In addition, the EMR also provides an extended range for the serving and neighbor cells downlink signal strength and the possibility to report altogether up to 15 GSM and/or WCDMA RAN neighbor cells in one report. These reports can be used by the network to enhance the generic performance of the existing system, enable GSM/WCDMA interworking, and enhance several features, such as: • • •
Automated Planning FER Measurement Intelligent Underlay Overlay (IUO) and Intelligent Frequency Hopping (IFH)
Interaction with other features: •
• •
The network does not order an MS to use the EMR for reporting when an Idle Broadcast Control Channel (BCCH) Allocation List or a Measurement BCCH Allocation List is used in active state in the serving cell. With Common BCCH Control, when a call is in a non-BCCH frequency band, the serving cell BCCH frequency is added to the BCCH frequency list. When the EMR is used for reporting, also the serving cell BSIC is added to the BSIC list before sending it to an MS.
Benefits • • •
36
Improved generic performance of the system Enables GSM/EDGE/WCDMA interworking Improved performance of statistics
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3.3 BSS21520: RF Sharing GSM - LTE The Flexi Multiradio BTS GSM/EDGE RF Modules can be used for GSM-only mode or for concurrent use with WCDMA and/or LTE. If Radio Modules are shared, then SW of Radio Modules can be managed by GSM or by the peer technology, WCDMA/LTE. The software version of the shared Radio Module can be different from that of the System Module SW version, when the software master is WCDMA or LTE. From the BSC point of view, Flexi Multiradio LTE support is visible when some or all RF Modules of Flexi Multiradio GSM/EDGE are configured as shared and some shared modules have LTE as SW master. The BSC receives SW master information in Abis O&M interface in ‘BTS type’ information element. Flexi Multiradio BTS usage is controlled with TRX capacity license. Requirements • •
BSC S15 EP1.2 Flexi Multiradio BTS EX4.1 or Flexi Multiradio 10 BTS GF1 1.0.0
Software Requirements Table 6
Software requirements
Network element
Software release
LTE
RL20 onwards
GSM/EDGE
EX4.1 onwards or Flexi Multiradio 10 BTS GF1 1.0.0
NetAct
OSS5.3 CD Set3 onwards
Hardware Requirements Table 7
Hardware requirements
Network element
Required hardware
BTS
Flexi 3-sector RF Module 850 70 W (FXCA) or, Flexi 3-sector RF Module 900 70 W (FXDA) or, Flexi 3-sector RF Module 900 90 W (FXDB) or, Flexi 3-sector RF Module 1800 70 W (FXEA) or, Flexi 3-sector RF Module 1800 90 W (FXEB) or, Flexi RF Module 1900 Tripe 70 W (FXFA) or, FHDA 900 band 2x40 W or, FHDB 900 band 2x60 W
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Flexi Multiradio 10 Base Station EDGE Feature Descriptions
Table 7
Hardware requirements (Cont.)
Network element
Required hardware or, FHEA 1800 band 2x40 W or, FHEB 1800 band 2x60 W and, Flexi BTS Multimode System Module (FSMC/D/E for LTE and ESMB/C for GSM)
g
GSM-LTE software support for each hardware depends on the market requirement.
3.4 Collecting logs using Snapshot feature The 2G Flexi BTS Site Manager can be used for collecting the logs using File -> Save As -> Save Snapshot option. It is recommended to collect logs using this feature everytime while troubleshooting the site or when a problem ticket is created.
g g
Snapshot is meant to help Nokia R&D to analyze and resolve the tickets. It cannot be opened or analysed in the field nor browsed with an off-line 2G Flexi BTS Site Manager. Not all internal logs are always available, so those will be skipped when the Snapshot is being fetched. For example, when the BTS is uncommissioned state, SCF and commissioning report will not be available. The following logs can be collected using Snapshot feature: 1. 2. 3. 4.
38
Site Information Report - Collect logs for complete site information. UKPT Logs - Collect internal logs for system module. Baseband memory dump - Collect baseband internal logs. Hardware Unit Logs - Collect RF Module/RRH internal logs.
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Figure 7
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Interworking
Collecting logs using Snapshot feature
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Flexi Multiradio 10 Base Station EDGE Feature Descriptions
4 Operability 4.1 2G Flexi BTS Manager Compatibility Launcher The Compatibility Launcher communicates with the BTS and with the installed 2G Flexi BTS Site Managers. It requests for parameters such as BTS SW version, Management interface version, and BTS type from the BTS and also fetches the SW version and Management interface version from the installed 2G Flexi BTS Site Managers. Based on the values of these parameters, the Compatibility Launcher launches the appropriate 2G Flexi BTS Site Manager. The following functionalities are supported in the Compatibility Launcher: • • • • •
Local connection with BTS Remote connection with BTS Create SCF file in offline mode for commissioning Display help for Flexi Multiradio 10 BTS Uninstall other versions of 2G Flexi BTS Site Manager
The following screenshot shows the Compatibility Launcher: Figure 8
Compatibility launcher-local connection
The following screenshot shows the Compatibility Launcher when it is trying to connect to the BTS.
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Figure 9
Operability
Compatibility launcher-connecting
In the Create File option, the user can select the desired 2G Flexi BTS Site Manager version to create the SCF file in offline mode. Figure 10
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Compatibility launcher-Create File option
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Flexi Multiradio 10 Base Station EDGE Feature Descriptions
Already installed versions of 2G Flexi BTS Site Manager can be deleted using the About option: Figure 11
Uninstall versions of 2G Flexi BTS Site Manager
4.2 BTS Trace Tool BTS Trace Tool is built in the 2G Flexi BTS Site Manager application and can be used to collect detailed logs when investigating a problem seen on a customer BTS site. The tool can be controlled either via local or remote 2G Flexi BTS Site Manager minimizing the need for site visits. The tool provides the functionality to collect logs remotely from the BTS site over the Abis link. In addition to a few standard logs, custom logs can be recorded as well with the help of custom trace set files provided by the Nokia customer support team. The recorded log files can be decoded and analyzed by Nokia.
4.3 Antenna VSWR measurement Flexi Multiradio BTS provides antenna line supervision by means of voltage standing wave ratio (VSWR) monitoring. VSWR monitoring is implemented in Main (TX/RX) antenna ports in Flexi Multiradio RF Module (FXxx) and Remote Radio Head module (FHxx). During commissioning, the user can set the VSWR minor (7607) and major (7606) alarm limits for each Main (Tx/RX) antenna line (or branch) separately. The minor and major limit can be set between 1.5 to 3.5 (in steps of 0.1). The default limits on the 2G Flexi BTS Site Manager are 1.9 (minor) and 2.6 (major), that is 10 dB (minor) and 7 dB (major) Return Loss respectively.
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Figure 12
Operability
Setting VSWR limits using 2G Flexi BTS Site Manager
At the end of the commissioning process, the values are stored in the site configuration file (SCF) in the System Module's (ESMB/C) non-volatile memory. The System Module then gives these values to commissioned RF modules or RRH. During normal BTS operation, RFM/ RRH modules continuously monitor Forward and Reverse TX power on their Main (Tx/Rx) antenna ports. The RFM/RRH then calculate the corresponding VSWR values every few seconds and compare them against the commissioned minor and major limits. Normal mode In normal mode, VSWR (return loss) can be monitored reliably if the forward TX power on the antenna port exceeds approximately +22.5 dBm in RRH (FHxx) and +21 dBm in RF Module (FXxx). This forward TX power is dependent on per TRX power (carrier power in SCF plan), attenuation level defined for the all carriers allocated to MCPA (PMAX, PMIN). If the calculated VSWR value exceeds either minor or major limit, RFM / RRH led turns red indicating a failure. If the failure continues or if no valid and good VSWR values are reported on the affected branch, the alarms 7607 TRX OPERATION DEGRADED or 7606 TRX FAULTY are reported after approximately 3 minutes. With 7607 alarm, the affected TRXs remain in operational state and the alarm is automatically canceled if the VSWR condition improves. With 7606 alarm, all affected TRXs are blocked and manual recovery is needed. Typical causes for a bad VSWR are broken cables, broken connectors and the ingress of water in the antenna cable path. Power tolerant mode VSWR monitoring can also be set to a "power tolerant" mode which can be used if the RF isolation between the antenna ports is continuously poor, for example, due to external combiner characteristics. Both minor and major VSWR alarms remain operational but higher Forward (and Reverse, respectively) power levels are needed to trigger any alarms. This mode can be activated by setting both minor and major limits to 3.5 (max value) during commissioning. In this mode, the following applies:
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Flexi Multiradio 10 Base Station EDGE Feature Descriptions
• •
g
g
RFM / RRH internally use the default values 1.9 and 2.6 for minor and major alarms respectively. VSWR alarms are only reported if alarming VSWR condition is present and the continuous TX Forward power has exceeded +37.8 dBm (RFM) / +36.0 dBm (RRH) for over 3 minutes. Like other BTS parameters, the VSWR minor and major values should be selected according to the physical BTS environment to ensure that BTS detects real VSWR problems but also does not raise unnecessary alarms. For example, the VSWR condition may be constantly poor if there are any causes for increased reverse power, like two Main antenna ports being connected in an external combiner with poor isolation causing RF leakage (reverse power) between the ports. The VSWR condition can also be expected to fluctuate if the antenna element vibrates during heavy wind periods. The expected VSWR / Return Loss measurement tolerance in the RFM and RRH HW circuitry is ±2.6 dB. So for example, when default VSWR minor limit 1.9 is used (=Return Loss 10 dB) the minor VSWR alarm (7607) is triggered if the real Return Loss condition is between 7.4 to 12.6 dB.
4.3.1 Antenna boosting on TCH-only TRX antenna lines If a RF module branch contains TCH-only TRXs, then RF module reports “Invalid VSWR” after 1 hour if there were no valid VSWR measurements during that period. This triggers so-called antenna boosting where BTS O&M SW activates one of the TCH TRXs on that branch for 3 minutes. If “Valid VSWR” value is reported before the timer expiry, the scenario is abandoned. If the RFM still reports "invalid VSWR" after timer expiry, a VSWR alarm is raised for all TCH TRXs allocated in this pipe. If BTS (sector) lock / unlock is given while the VSWR alarm is active, antenna boosting is also done to verify the TCH-only antenna line condition after recovery.
4.4 BSC download of Abis mapping Abis mapping automates the process of providing Abis allocations on the BTS. Instead of using the information from the Site Configuration File (SCF), the BTS configures the allocation of the Abis using the information received from the BSC. This configuration is performed by the BTS, by using mapping algorithms to convert BSC data into BTS Abis allocations. The mapping between the BSC data and the interfaces at the BTS relies on reference signals that are collectively known as the Abis Termination information of the BTS. The Abis mapping information is provided to the BTS. The Abis Termination information is provided to the BTS during commissioning via SCF from the 2G Flexi BTS Site Manager. One reference signal per interface is supported at the BTS.
g
A restriction with this feature is that it might be unable to take into account the possible cross-connections in the Abis line. The BTS believes the Abis timeslot allocations as defined on BSC but they may not be the same anymore on the BTS end due to crossconnections (if TS offset is also used). An Abis mapping Information Element (IE) consists of Abis channels (TRXSIG and TCH) in BTS_CONF_DATA grouped into a bundle. The BTS_CONF_DATA can carry several instances of Abis mapping IE(s), one for each bundle or interface. The interface time
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slots in the Abis mapping IE(s) from the BSC are the time slots at the BSC interface. OMUSIG configuration is still taken from the Abis Termination information already stored at the BTS, and not from the Abis mapping IE. The timeslot information provided in the Abis mapping IE is converted into timeslot information for the BTS via the Abis mapping algorithm. EDAP information is provided using the Dynamic Pool Info IE(s) in the BTS_CONF_DATA. The interface time slots in the Dynamic Pool Info IE(s) are the time slots at the BSC interface. At the BTS, one bundle per interface is supported, and, at the BSC, multiple bundles per interface are supported. However, one bundle cannot include multiple interfaces. The 2G Flexi BTS Site Manager supports Abis mapping download function: •
The Transmission menu of the 2G Flexi BTS Site Manager has the BSC Abis Mapping Status view menu item. This is enabled when the BSC Abis Mapping feature is in use, and disabled when the feature is not in use. –
– •
The BSC Abis mapping facilitates the user to view the differences and conflicts in the BSC and BTS allocations for a selected interface or a BSC bundle. The user can select an interface from the list of interfaces displayed in the Transmission equipment view or select a BSC bundle from an available list of bundles. As per user selection, the details of the BTS interface, reference signal and the calculated offset value are displayed. This is only available in online mode for already commissioned BTS.
Two check boxes have been added for the BSC Abis mapping download function in the Abis Termination screen of the Commissioning Wizard: – –
–
Enable Abis Signal Mapping allows the user to enable/disable the Abis signal mapping. Allow Abis Allocations from 2G Flexi BTS Site Manager allows the user to enable/disable the Abis allocations from the 2G Flexi BTS Site Manager. If this check box is selected and the user enters the Abis allocations from the 2G Flexi BTS Site Manager, they might later be overwritten by the allocation data from the BSC. These options are available in both online and offline mode.
4.5 BSS20847 Automatic commissioning of the Flexi Multiradio BTS GSM/EDGE Flexi Multiradio BTS GSM/EDGE is designed so that it is easy to install and commission. Easy commissioning needs support also from the BSC. The following functions are related to the automatic commissioning of the Flexi Multiradio BTS GSM/EDGE: •
Issue: 01F
The BSC must be able to download Abis mapping to the BTS as Abis mapping allows the BSC to dynamically provide the Abis allocations (TRXSIG, TCH, and EDAP) for a BTS. The BTS configures the Abis allocations of the TRXSIGs, TCHs, and EDAPs using the information received from the BSC, instead of getting the information in the SCF. The mapping between the BSC data and the interfaces at the BTS relies on reference signals (one per interface (E1/T1) at the BTS) which are collectively known as the Abis termination information of the BTS. The Abis termination information is provided to the BTS during commissioning via SCF from the 2G Flexi BTS Site Manager.
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Flexi Multiradio 10 Base Station EDGE Feature Descriptions
•
When the site is commissioned, the BSC must automatically unlock the BCF when the BTS informs that it is ready. The 'Auto unlock allowed' is a configurable functionality (a BCF-level parameter in the BSC).
4.6 BSS20817 End to End Downlink Abis Performance Monitor BSS20065, in BSC S11.5 SW, implements counters in the BSC that check the uplink signalling channels (channels using LAPD), keeps the results in a set of counters, and every 24 hours checks the number of errors (CRC errors) against an alarm threshold. BSS20817 is an equivalent feature for the Downlink Abis. The BTS keeps downlink counters for each LAPD connection that terminates in the BTS. The counters measure the number of received bytes, the number of CRC errors and the number of T200 timeouts. The BTS reports the counter numbers, per channel, every hour between 10 minutes before the hour and the top of the hour according to the BTS real-time clock.
4.7 BSS20063 Space Time Interference Rejection Combining The Space Time Interference Rejection Combining (STIRC) is a licence-based application software in the BSC that enables/disables the use of STIRC technology in the BTS. The STIRC is an uplink (UL) receiver performance enhancement to the Interference Rejection Combining (IRC) technology. When enabled, the STIRC technology is deployed in the UL by BTS. When disabled, the current IRC technology is deployed by the BTS. The new technology improves the spectral efficiency of the network via link performance enhancement that significantly improves the interference (co-channel and adjacent channel) rejection capability of Flexi Multiradio BTS in the uplink direction. For example, the improved link level interference rejection performance of the STIRC with GMSK modulation will give on average a gain of 4 to 9 dB for co-channel interference compared to the IRC in 2-way Uplink Diversity (2UD) configurations. In addition, the current GMSK normal burst receiver sensitivity levels are not affected. The STIRC can also help to maintain the link balance (UL and DL) needed with the deployment of Single Antenna Interference Cancellation (SAIC) technology in mobiles that improves interference cancellation capabilities in the downlink (DL). The STIRC licensing software will be operational once the STIRC option is enabled at the BSC. The BSC will allocate the STIRC license from its available pool and send the STIRC option in the BTS_CONF_DATA to the BTS. This feature affects alarm handling so that STIRC alarms can be cancelled without reset.
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Implementation The STIRC feature can be enabled or disabled for the site any time the BTS is running because it does not require locking the sector or TRX. The BSC will send the STIRC option for each sector in the BTS_CONF_DATA. When receiving this option, the BTS O&M SW checks for each TRX in the sector for which STIRC is enabled, whether the HW configuration is valid for the STIRC feature. If an invalid configuration is used, an alarm is raised on the specific TRX(s) and these specific TRX(s) are blocked, and STIRC is enabled on rest of the TRX(s). BTS O&M SW enables the STIRC algorithm by informing the DSP of each valid TRX in the sector. Note that the STIRC algorithm implementation requires 32-bit precision numerical calculations to minimize quantization errors, while for the IRC algorithm 16-bit precision is sufficient. Thus, for STIRC implementation 32-bit precision is used for all the functions, some of which are common to the IRC algorithm also. As a result of this, slight gain (up to 0.2 dB) in CCI and ACI performance can be observed even when the IRC algorithm is used (STIRC=N). In order to achieve the STIRC gain, Rx Diversity should be in use (RDIV=Y).
Requirements This feature is supported by the following BTS generations and SW: • • • • • •
Flexi EDGE EP2 UltraSite CX5 with EDGE TRXs (BB2E/BB2F and TSxB) and Hybrid TRX (BB2E/BB2F and TSxA). MetroSite CXM5 with EDGE TRXs BSC S12 EX3.1 Flexi Multiradio Flexi Multiradio 10 BTS GF1.0
Interaction with other features • •
All valid hopping combinations for the supported TRX types are supported. BSS synchronisation helps in achieving full STIRC gain.
Benefits The STIRC diversity algorithm improves the interference rejection performance and thus the overall network spectral efficiency and quality. The STIRC ensures better uplink quality, particularly in high user density/interference limited scenarios, and better average user data throughput, as well as improved traffic and control channel performance. It also provides a possibility to use less mobile Tx power for quality-based uplink power control, which leads to reduction in the overall interference level in uplink and improves the mobile battery life.
4.8 BSS20040 User Access Level Control (UALC) The User Access Level Control (UALC) is a solution to prevent unauthorized users from making changes that can affect the remote management and traffic. The UALC is for a remote connection only, in a local connection it is not in use.
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The UALC defines two levels of access rights for the users of 2G Flexi BTS Site Manager: • •
Full Access (Read and Write) means that all the functions that the manager applications offer are available to the user. Limited Access (Read only) allows only to read information from an element.
Assignment of user rights is via the existing Windows user management processes. The 2G Flexi BTS Site Manager applications can start-up and operate independently regardless of the Windows User Administration. The 2G Flexi BTS Site Manager applications check if the User Access Level Control is enabled or disabled by reading the registry key 'Access Levels' under KEY_LOCAL_MACHINE/Software/Nokia/2G Flexi BTS Site Manager: • •
'ON' – UALC is enabled. 'OFF' – UALC is disabled.
If the UALC is disabled, the application gives Full Access Rights (both Read and Write) to the user. If the registry key is not present, by default Full Access Rights are granted. In case the UALC is 'ON', that is, enabled, the EM application checks if the user currently logged in belongs to the Nokia BTS_Administrator group or not. If yes, the user is given Full Access Rights (both Read and Write). Otherwise, Limited Access Rights (Read only) are granted. If the Nokia BTS_Administrator group is not present on the PC/domain, by default Limited Access Rights are granted. In case 2G Flexi BTS Site Manager is installed and the BTS_Administrator group does not exist on the PC, the user can create the group either using a SiteWizard installer or manually.
Creating the Nokia BTS_Admins user group manually To create the Nokia BTS_Admins user group manually, follow the instructions below. Add the PC's login ID to the Nokia BTS_Admins group using the Control panel. 1. Go to Control Panel > User Accounts. 2. Click on the Advanced tab and then the Advanced button. A new window Local users and groups is displayed. 3. Select a group and then create a new group 'Nokia BTS_Admins' by right-clicking on RHS. 4. Select the newly created group, right-click the Add to group option, and then click Add. The Select Users, Computers, or Groups window is displayed. 5. Enter your PC login ID to the 'Enter the object names to select' and click OK.
Creating the User Access Level Key manually To create the Access Levels key manually, follow the instructions below. Registry location: KEY_LOCAL_MACHINE/Software/Nokia/2G Flexi BTS Site Manager Access Level Key name: Access Levels Value: ON 1. Open the Command Window, type regedit, and press Enter to open the 'Registry Editor'.
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2. Go to HKEY_LOCAL_MACHINE/Software. 3. Create a 'Nokia' Key by right-clicking on Software > New > Key, if not present. 4. Create a '2G Flexi BTS Site Manager' Key by right-clicking on Nokia > New > Key, if not present. 5. Create 'Access Levels' string values by right-clicking on 2G Flexi BTS Site Manager > New > String Values. 6. Modify the value of 'Access Levels' by right-clicking on Access Levels > Modify. Type ON in the value data and press Ok.
4.9 BSS11047 Intelligent shutdown for Flexi Multiradio BTS GSM/EDGE To provide protection against a mains power break, the operator can equip a BTS with a battery backup system. The “Intelligent shutdown” feature is controlled by the BSC and its purpose is to maintain the BTS site operation for as long as possible by reducing capacity so that only the essential site functions are maintained. When a mains breakdown takes place, then BTS sends an alarm to the BSC, which performs forced handovers for all the calls on the TRXs to be shut down. The calls are handed over to a TRX, which will remain powered, or to adjacent cells and finally the BSC orders the BTS site to stop transmission for the TRXs involved. When the main power is restored the BSC takes the BTS automatically back in full service. On a BTS site basis, the user can define the service level of the site to be maintained while the battery backup is in use. Also, two timers can be defined, allowing the execution of the shutdown procedure in phases, reducing capacity in a controlled way. Three service level options are available: • •
•
Full service – Service is maintained at full capacity for as long as the battery power supply lasts. The two timers are ignored. Broadcast control channel (BCCH) backup – The BTS maintains full capacity until the first timer expires. After that, all active calls on non-BCCH transceivers are handed off. The non-BCCH transceivers are blocked from carrying any new calls and the BSC commands the BTS to shut them down. The BCCH TRX(s) are maintained to offer minimum service. Transmission backup – The second timer starts after the first one has expired. After the expiry of the second timer, all active calls on BCCH transceivers are handed over. The BCCH transceivers are blocked from carrying new calls and the BSC commands the BTS to shut them down. Only the BTS transmission equipment power is maintained to secure the functionality of a transmission chain for as long as the batteries last.
When the mains power is restored, the BSC commands the BTS site to power all the shut down equipment and return back to full service. Battery backup configurations for Flexi Multiradio BTS GSM/EDGE: • • •
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Flexi Multiradio 10 Base Station EDGE Feature Descriptions
The optional battery backup system for the Flexi Multiradio BTS GSM/EDGE is selected in the 2G Flexi BTS Site Manager during the commissioning phase. If 3rd party BBU solution is used, one external alarm (EAC) line needs to be designated to indicate a mains power loss/restoration from the BBU. The selected EAC line needs to be configured as a Mains alarm at the BSC. If Nokia BBU solution (FPxA, MIBBU or FPRx) is used, the FPA connector on the ESMB/C System Module can be used with no need to use nor configure any EAC lines. Note that if an EAC line is configured as a Mains alarm at the BSC, the BTS ignores the FPA connector. With all BBU solution options, the BTS generates alarm 7995 Mains Breakdown when the BBU indicates mains power loss. The 7995 alarm then triggers the Intelligent Shutdown procedure at the BSC. If two or three phase supply is used with MIBBU or FPRx, the loss of one phase already generates the 7995 alarm. In addition to alarm 7995, the FPA interface can also generate three other BBU-related alarms 7612/7613/7614 (note that with FPMA, only 7995 and 7613 alarms can be seen).
Benefits The operation is optimal during both short and long mains breaks. Timers allow executing the shutdown procedure in several phases. Each phase reduces the battery power consumption. With intelligent shutdown, the operator can define the service level to be applied on a mains failure to optimize the trade-off between the service level and battery power lifetime. A short mains break will not reduce the service unnecessarily, whereas during a longer break, the essential functions, such as BCCH or transmission chain, are maintained for as long as possible.
4.10 Remote mode of 2G Flexi BTS Site Manager The user can control Flexi Multiradio BTS equipment locally via 2G Flexi BTS Site Manager. To minimize the need for site visits, 2G Flexi BTS Site Manager functions can also be accessed remotely. The user can monitor and test the BTS remotely, by connecting the 2G Flexi BTS Site Manager to the BTS remotely via NetAct™. A PC with the 2G Flexi BTS Site Manager software is used as a user terminal.
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Figure 13
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2G Flexi BTS Site Manager connected in remote mode
The user can connect to a remote BTS using the 2G Flexi BTS Site Manager application, via a menu item and/or a toolbar button, or via the command line. The user interface of 2G Flexi BTS Site Manager informs the user of the remote connection status when information is being requested from the remote BTS, and when the 2G Flexi BTS Site Manager is processing received information from a remote BTS. 2G Flexi BTS Site Manager connected in remote mode supports all features available via a local connection, except the Control Abis interface (enable/disable) commands. It is not possible to perform the initial BTS commissioning remotely, but it is possible to perform subsequent recommissioning or append commissioning from the 2G Flexi BTS Site Manager in remote mode. At the BTS, the messages sent from or to the 2G Flexi BTS Site Manager in remote mode are re-routed, but handled in the same way as with the local connection. The alarm 7801 MMI CONNECTED TO BASE STATION indicates whether the 2G Flexi BTS Site Manager is connected to the BTS locally (alarm text Local MMI connected) or remotely from NetAct (alarm text Remote MMI connected).
4.11 BSS10063 Rx Antenna Supervision by Comparing RSSI The purpose of Rx Antenna Supervision by Comparing received signal strength indicator (RSSI) is to monitor the Rx antenna condition. Rx antennas can be monitored for major problems by taking a long-term average of the difference between the Main Rx RSSI and the Div Rx RSSI. This feature provides continuous antenna supervision for the BTSs, which have the Main Rx RSSI and the diversity in use. It also offers an alternative solution for Tx monitoring in cells that use duplexing. This detects, for example, antennas with poor voltage standing wave ratio (VSWR) and inadequate feeders.
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Flexi Multiradio 10 Base Station EDGE Feature Descriptions
The monitoring is based on the principle that all received bursts where the Rx level of main or diversity branch is above the defined limit value (-100 dBm) are accepted as samples and used in the averaging process. A minimum of 160000 samples in one hour must be collected for the BTS to assume that the results are reliable and therefore could be used to raise an alarm. The differences of the TRXs connected to the same antennas are counted up, and the average difference for main and diversity antennas is calculated. If the difference is above the threshold (default value 10 dB), and the number of samples indicate that the results should be reliable, an alarm is activated. The threshold default value of 10 dB can be changed by a parameter at the BSC between 3 and 64. The functionality of the feature can be disabled. It is still possible that both antennas are damaged simultaneously and the samples from both antennas remain below -100 dBm limit value. Therefore, the difference algorithm cannot detect the fault. For this reason, the BSC also observes the assignment and handover success rate. Note that the RSSI values observed from 2G Flexi BTS Site Manager may not be the same on both of the carriers of a RF Module. The difference between carriers can be greater than 10 dB, depending on the Rx level of the calls made on both carriers. If the average uplink Rx level of calls (CS/PS) made on Carrier 1 is high compared to Carrier 2, this difference can be seen and this is not a problem. It implies that calls on Carrier 1 are being made from mobiles that are near to the BTS, while calls on Carrier 2 are being made from mobiles that are relatively far from the BTS. The RSSI difference between two carriers is different from the case where an RSSI alarm is raised. The alarm is raised because of the difference in the Rx level of the main and diversity paths of a carrier. However, this alarm is not valid for the comparison done across carriers. Moreover, the comparison of RSSI values across carriers is not valid in Nokia UltraSite EDGE BTS, as a TRX in the UltraSite EDGE BTS supports one carrier only, whereas in the Flexi Multiradio BTS, the RF Module supports two carriers.
Benefits Rx Antenna Supervision by Comparing RSSI can identify antenna problems without the need for active tests.
Collection and display of raw RSSI measurements In addition to the newest and last reliable received signal strength indicator (RSSI) values, the BTS also gathers the raw RSSI results periodically from the TRXs. These results are displayed in the 2G Flexi BTS Site Manager.
Settable RSSI sample limit The number of received signal strength indicator (RSSI) samples, needed for a valid RSSI calculation, can be configured using the Element Manager according to the traffic density. The RSSI sample can be configured to values: 80000, 160000 (default), 350000 and 750000. The value 80000 is preferred when the BTS is located in a rural area and when the traffic density is low. The values 350000 or 750000 are preferred when the BTS is located in an urban area and has high capacity utilization. In areas with intermediate traffic density it is preferred to use the default value 160000. The RSSI sample value may also be configured during the commissioning phase.
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Alarm Start and Cancel The BTS estimates the number of samples it would receive for high/medium traffic profiles by setting an internal threshold value, which is a multiple of the user defined RSSI sample count. This value is an internal value and is not visible to the user. The RSSI alarm is raised when: • •
•
In the first hour, the received sample count is greater than the internal threshold and the RSSI alarm conditions are valid. In the first hour the received sample count is greater than the user configured RSSI sample threshold, but less than the internal RSSI alarm threshold. Then, the BTS software waits for the next hour to determine whether the RSSI alarm is to be raised. In the consecutive second hour the received sample count is greater than the internal RSSI alarm threshold or the user configured RSSI sample threshold and the RSSI alarm conditions are valid. If the user configurable sample count is changed during this hour then the monitoring is reset and the process restarts from the first hour.
The alarm is cancelled automatically in the next hour if the sample count is greater than the user configured sample count and the alarm condition has been cleared.
4.12 BSS9068 BTS SW management The BTS software package consists of a master file and several application files. You can update the BTS software by downloading the new BTS software remotely from the BSC. A site visit is not needed. You can download the BTS software to a BCF in the background during normal operation, without impact to ongoing traffic or any other operation of the base station. Software downloading is also automatically triggered after BCF reset if the System Module does not have the correct BTS software package stored locally (that is, the package set as default for that particular BCF at the BSC). When the BTS software is downloaded from the BSC, the process is optimized by downloading only those application files which have been updated. Application files that are unchanged from those already stored locally in the current BTS software package are not downloaded. This minimizes the download time for a new BTS software package. RF Module and RRH software is included in the BTS SW package and is automatically upgraded or downgraded whenever the BTS SW package is upgraded or downgraded. You can also download the BTS software with 2G Flexi BTS Site Manager to minimize BTS boot-up time for new installations. In this case you do not need to download the BTS software package from the BSC after BCF reset. The downloaded BTS software package is stored in the flash memory of the System Module (ESMB/C). The flash memory of the System Module contains two complete BTS software packages to ensure recovery in the event of a download or start-up failure.
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4.13 BSS9058 BTS fault recovery BTS fault recovery minimizes the effect of service level faults within the BTS. All objects and interfaces are continuously monitored, and appropriate recovery actions are taken when needed. Alarms are raised to indicate faults, which leads to recovery actions being taken. For more information on fault recovery and BTS alarms, see Trouble Management of Flexi Multiradio BTS GSM/EDGE.
4.14 BSS9063 Abis loop test The purpose of the Abis loop test is to verify the Abis transmission set-up and quality. During the Abis loop test, Flexi Multiradio BTS generates a test signal pattern in Abis uplink for the timeslots under test. The BSC group switch loops the selected timeslots back to Abis downlink where the BTS checks the integrity of the received signal. The Abis loop test can be run on the TCH and Dynamic Abis Pool timeslots. After the test, the BTS provides the related test reports to the BSC. The Abis loop test is run automatically during BTS commissioning. The test can also be run manually from the BSC. Up to 12 simultaneous Abis loop tests can be tested if no Abis protection loops are used. If they are used, then up to 6 Abis loop tests can be run simultaneously. This feature is not supported with Packet Abis.
4.15 BSS9062 BTS supervision The Flexi Multiradio BTS Base Station monitors and tests itself during operation without a separate command.
Continuous monitoring Both the software and hardware carry out monitoring. Most of the monitoring procedures are so effective that no additional testing to find the faulty module is needed. The following items are monitored continuously: • • • • • • • •
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Internal buses of the base station Transmission equipment and interfaces RF parts Mast head amplifiers Flexi Support and Flexi Multiradio BTS Base Station Battery Backup (MIBBU) Temperature (heating and cooling) system of the base station Power supply voltages Reference Oven Oscillator
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AC mains breakdown A typical short voltage drop (that lasts less than 20 ms) in the AC mains supply does not cause any detectable harm to the operation and does not cause an alarm. In case of a mains breakdown, the Flexi Multiradio BTS Base Station cannot send an alarm to the BSC without battery backup (either integrated or external).
4.16 BSS9061 Temperature control system Flexi Multiradio BTS Base Station monitors its temperature continuously with several sensors located in the System Module (ESMB/C) and RF Module (FXxx). The BTS controls its temperature with cooling fans to provide as stable operational conditions as possible. Heating and cooling is controlled gradually depending on the ambient temperature to ensure low temperature gradients and noise level. During BTS start up, System module and Radio Modules can be powered on from the ambient temperature of –35˚C (-40˚C, in case of 2x60 W RRH). When ambient temperature is outside normal range (
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