Common Radio Resource Management

SingleRAN

Common Radio Resource Management Feature Parameter Description

Copyright © Huawei Technologies Co., Ltd. 2011. All rights reserved. No part of this document may be reproduced or transmitted in any form or by any means without prior written consent of Huawei Technologies Co., Ltd.

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SingleRAN Common Radio Resource Management

Contents

Contents 1 Introduction ................................................................................................................................1-1 1.1 Scope ............................................................................................................................................ 1-1 1.2 Intended Audience ........................................................................................................................ 1-1 1.3 Change History.............................................................................................................................. 1-1

2 Overview of Co-RRM ................................................................................................................2-1 2.1 Introduction.................................................................................................................................... 2-1 2.2 Purposes ....................................................................................................................................... 2-1

3 Cell Load Information Sharing ..............................................................................................3-1 3.1 Common Measurement Procedure ............................................................................................... 3-1 3.2 Cell Load Information .................................................................................................................... 3-2

4 Handover Based on Load Enhancement ............................................................................4-1 4.1 UMTS Handover Based on Load Enhancement ........................................................................... 4-1 4.1.1 Load-Based Inter-RAT Handover Enhancement .................................................................. 4-1 4.1.2 Inter-RAT Handover based on Hierarchical Cell Structure Enhancement............................ 4-2 4.2 GSM Handover Based on Load Enhancement ............................................................................. 4-2

5 Service Distribution .................................................................................................................5-1 5.1 UMTS-to-GSM Service Distribution .............................................................................................. 5-1 5.1.1 CS Service Distribution During RRC Setup.......................................................................... 5-1 5.1.2 Service Distribution After RAB Setup ................................................................................... 5-2 5.2 GSM-to-UMTS Service Distribution .............................................................................................. 5-3

6 Load Balancing .........................................................................................................................6-1 6.1 UMTS Load Balancing .................................................................................................................. 6-1 6.1.1 Load Balance During RRC Setup......................................................................................... 6-1 6.1.2 Load Balancing After RAB Setup ......................................................................................... 6-2 6.2 GSM Load balancing ..................................................................................................................... 6-3

7 NACC Procedure Optimization..............................................................................................7-1 8 Engineering Guidelines...........................................................................................................8-1 9 Parameters .................................................................................................................................9-1 10 Counters .................................................................................................................................10-1 11 Glossary ..................................................................................................................................11-1 12 Reference Documents .........................................................................................................12-1

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SingleRAN Common Radio Resource Management

1 Introduction

1 Introduction 1.1 Scope This document describes the common radio resource management (Co-RRM) based on Iur-g interface. It covers information exchange between GSM and UMTS system over on Iur-g interface, GSM/UMTS handover based on load enhancement, GSM/UMTS service distribution, GSM/UMTS load balancing, and UMTS NACC procedure optimization. For ease of description and understanding, this document mainly describes the requirements for candidate cells during the inter-RAT handover between GSM and UMTS. Before reading this document, you need to learn the handover mechanisms for GSM and UMTS, and the GSM and UMTS interoperability. You are advised to read the following documents: The Handover Feature Parameter Description of the GBSS, the Handover Feature Parameter Description of the RAN, and the Interoperability Between GSM and WCDMA Feature Parameter Description of the GBSS.

1.2 Intended Audience This document is intended for: 

Personnel who are familiar with WCDMA and GSM basics



Personnel who need to understand Co-RRM feature



Personnel who work with Huawei products

1.3 Change History This section provides information on the changes in different document versions. There are two types of changes, which are defined as follows: 

Feature change: refers to the change in the Co-RRM feature.



Editorial change: refers to the change in wording or the addition of the information that was not described in the earlier version.

Document Issues The document issues are as follows: 

01 (2011-03-30)



Draft A (2010-12-30)

01 (2011-03-30) This is the document for the first commercial release of SRAN6.0. Compared with issue Draft A (2010-12-30) of SRAN6.0, this issue optimizes the description.

Draft A (2010-12-30) This is the draft of the document for SRAN6.0. Compared with issue 01 (2010-10-15) of SRAN5.0, this issue optimizes the description.

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2 Overview of Co-RRM

2 Overview of Co-RRM Through cell load information sharing, Common Radio Resource Management (Co-RRM) makes full use of the advantages of both GSM and UMTS. With the Co-RRM feature, radio resources of GSM and UMTS can be managed collectively and efficiently.

2.1 Introduction The Co-RRM feature utilizes information exchange between GSM and UMTS over the Iur-g interface to support the following functions and mechanisms: 

Cell Load Information Sharing



Handover Based on Load Enhancement



Service Distribution



Load Balancing



NACC Procedure Optimization

Through the internal information exchange, the load information of GSM and UMTS cells can be shared, and the procedure of Network Assisted Cell Change (NACC) can be optimized. Handover based on load enhancement, service distribution, and load balancing are based on the traffic load of GSM/UMTS cells and the characteristics of each network. The main difference between the three functions is the requirements for candidate cells during inter-RAT handover. The following sections provide the detailed description for each function. The BSC6900 is a GSM+UMTS multi-mode base station controller (MBSC) of Huawei. It implements the functions of both UMTS RNC and GSM BSC, as shown in Figure 2-1. In this document, the base station controller is referred to as BSC regarding GSM functions and as RNC regarding UMTS functions. Figure 2-1 BSC6900 in Co-RRM

2.2 Purposes In Co-RRM, several GSM/UMTS interoperability functions are optimized in the BSC6900 to achieve better network convergence and enhance network throughput. Some major advantages achieved through the Co-RRM feature, utilizing internal information exchange are:

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2 Overview of Co-RRM



The load information of the GSM and UMTS neighboring cells can be shared, which enhances the load control capability between GSM and UMTS.



The accuracy of the load information for handover decision between GSM and UMTS is enhanced, reducing the risk of ping-pong effect.



The service load can be distributed based on the conditions in the GSM and UMTS networks through RRC redirection and service-based inter-RAT handover. This enables the GSM network to handle voice services and the UMTS network to handle high-speed PS services



The service load can be distributed based on the service attributes and the conditions in the GSM and UMTS networks through RRC redirection and load-based inter-RAT handover. In this way, the load on the two networks in the same coverage area is increased evenly so the risk of network congestion due to load imbalance is reduced and the total network capacity is enhanced.



The CN does not need to be involved in the GSM/UMTS PS NACC procedure under one BSC6900. In this way, the execution time for the NACC procedure is shortened and the PS service handover delay is reduced. In addition, an NACC solution is also provided when the CN does not support the RIM procedure.

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3 Cell Load Information Sharing

3 Cell Load Information Sharing The load information sharing between GSM and UMTS cells is achieved through a common measurement procedure in internal information exchange. This involves a procedure through which the BSC obtains the load information of UMTS neighboring cells and a procedure through which the RNC obtains the load information of GSM neighboring cells. Through load information sharing, the load information of the cells of different systems can be obtained, avoiding unnecessary handover attempts.

3.1 Common Measurement Procedure The basic procedure behind the cell load information sharing is a BSC6900 internal information exchange mechanism, where the BSC side of the BSC6900 sends a COMMON MEASUREMENT INITIATION REQUEST message to the RNC side and vice versa to initiate the common measurement procedure, requesting the target RNC/BSC to report the load information of its neighboring cells. If the target RNC/BSC supports the common measurement, it responds with a COMMON MEASUREMENT INITIATION RESPOSE message; otherwise, it responds with a COMMON MEASUREMENT INITIATION FAILURE message. After a successful common measurement initialization, the target RNC/BSC sends the COMMON MEASUREMENT REPORT message to the source BSC/RNC periodically to report its load information. If the measurement fails to be further performed, for example, when the cell is faulty, blocked, deleted, or deactivated, the common measurement is stopped. In this case, the target RNC/BSC sends a COMMON MEASUREMENT FAILURE INDICATION message to the source BSC/RNC. Figure 3-1, Figure 3-2, Figure 3-3 and Figure 3-4 show the common measurement procedure. Figure 3-1 Successful common measurement initialization

Figure 3-2 Failed common measurement initialization

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3 Cell Load Information Sharing

Figure 3-3 Common measurement reporting procedure

Figure 3-4 Failed common measurement

3.2 Cell Load Information During the common measurement procedure, load information related to GSM and UMTS cells, is shared between the BSC and RNC sides of the BSC6900. In addition, the GSM cell sends the information that whether it supports inter-RAT handover. There are three load states: normal, basic congestion, and overload congestion. With uplink direction in GSM as an example, an uplink load lower than GSM uplink basic congestion threshold (UlLdrThrd2GCell) represents the normal state. An uplink load above this threshold but below the GSM uplink overload congestion threshold (UlOlcThrd2GCell), represents the basic congestion state. An uplink load above this threshold represents the overload congestion state. The BSC side of the BSC6900 sends the inter-RAT handover support information to indicate whether the CS/PS services can be handed over from a UMTS cell to a GSM cell. The inter-RAT handover support information includes the inter-RAT CS service handover support flag and the inter-RAT PS service handover support flag. If the inter-RAT CS service handover support flag is enabled, the corresponding GSM cell can be the target cell of the inter-RAT CS service handover from a UMTS cell; if the inter-RAT PS service handover support flag is enabled, the corresponding GSM cell can be the target cell of the inter-RAT PS service handover from a UMTS cell.

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4 Handover Based on Load Enhancement

4 Handover Based on Load Enhancement The handover based on load enhancement function corresponds to the feature MRFD-211404 MBSC Handover based on Load Enhancement. When the Co-RRM feature is used, the BSC6900 can select the target cell according to the traffic load in the cell before initiating an inter-RAT handover, reducing the ping-pong handover between GSM and UMTS and enhancing the network usage.

4.1 UMTS Handover Based on Load Enhancement The UMTS handover based on load enhancement function corresponds to the feature WRFD-070004 Load Based GSM and UMTS Handover Enhancement Based on Iur-g. Through the internal load information sharing mechanism, the load-based inter-RAT handover is enhanced in the UMTS. 

In the load-based inter-RAT handover, the UMTS selects the target GSM cell according to the load on the GSM neighboring cell and the load difference between the UMTS cell and the GSM neighboring cell.



In the inter-RAT handover based on hierarchical cell structure, the UMTS selects the target GSM cell depending on the load on the neighboring cells.

The following paragraphs provide further descriptions of the two handover modes.

4.1.1 Load-Based Inter-RAT Handover Enhancement When the indication of non-coverage-based handover based on GSM load (MBSCNcovHoOn2GldInd) and the indication of load-based handover based on the load difference between UMTS and GSM (LoadHoOn3G2GldInd) are set to ON, the load-based handover to the GSM cell is triggered when the traffic load on the UMTS cell is high. The RNC performs handover decision based on the load on the neighboring GSM cell and the load difference between the UMTS cell and the neighboring GSM cell. For the CS service, a GSM candidate cell must meet the following conditions: 

The cell supports the inter-RAT handover for CS services.



The load on the cell is lower than the CS outgoing inter-RAT handover GSM load threshold (CSHOOut2GloadThd).



The load of UMTS source cell minus the load of the cell is higher than the threshold of CS load difference between UMTS and GSM (Mbsc3G2GLdBlcCsDeltaThrd).

For the PS service, a GSM candidate cell must meet the following conditions: 

The cell supports the inter-RAT handover for PS services.



The load on the cell is lower than the PS outgoing inter-RAT handover GSM load threshold (PSHOOut2GloadThd).



The load of UMTS source cell minus the load of the cell is higher than the threshold of PS load difference between UMTS and GSM (Mbsc3G2GLdBlcPsDeltaThrd).

The RNC initiates the handover to the best GSM candidate cell.

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4 Handover Based on Load Enhancement

4.1.2 Inter-RAT Handover based on Hierarchical Cell Structure Enhancement When the indication of non-coverage-based handover based on GSM load (MBSCNcovHoOn2GldInd) is set to ON, the handover to the GSM cell is triggered when the traffic load on the UMTS cell is high. The RNC performs the handover decision depending on the load on the GSM neighboring cell. For the CS service, a GSM candidate cell must meet the following conditions: 

The cell supports the inter-RAT handover for CS services.



The load on the cell is lower than the CS outgoing inter-RAT handover GSM load threshold (CSHOOut2GloadThd).

For the PS service, a GSM candidate cell must meet the following conditions: 

The cell supports the inter-RAT handover for PS services.



The load on the cell is lower than the PS outgoing inter-RAT handover GSM load threshold (PSHOOut2GloadThd).

4.2 GSM Handover Based on Load Enhancement The GSM handover based on load enhancement function corresponds to the feature GBFD-511101 Load Based Handover Enhancement on Iur-g. When the inter-RAT load handover switch (OutSysLoadHoEn) is set to ON, the load-based handover from GSM to UMTS is triggered if the load on the GSM cell reaches load handover threshold and the Service Handover attribute of the current service is not "handover to UTRAN or cdma2000 shall not be performed". The BSC checks all the neighboring UMTS cells. If the load of the GSM source cell minus the load of a neighboring UMTS cell is higher than the threshold of CS load difference between UMTS and GSM (G2G3GLdBlcDeltaThrd) and the level of the neighboring UMTS cell exceeds the load handover threshold, the UMTS cell is taken as a candidate cell. The BSC initiates the handover to the optimal UMTS candidate cell.

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5 Service Distribution

5 Service Distribution The service distribution function corresponds to the feature MRFD-211403 MBSC Service Distribution. The GSM and UMTS networks have different characteristics and capabilities with respect to services that can be provided. The GSM network carries CS services and low-rate data services. The UMTS network is characterized by high data rate and large capacity, which ensures the high data rate and short delay of the data services; however, when high CS traffic load runs on the UMTS network, delay is extended for CS services. Therefore, comparing a UMTS network running only data services, system throughput is considerably decreased. To optimize the utilization of resources in the GSM and UMTS networks, service distribution is introduced. The inter-RAT service distribution is performed in two directions: UMTS to GSM (controlled by the RNC) and GSM to UMTS (controlled by the BSC). As a result of load-based system redirection and handover, the CS services will mainly be handled by the GSM network whereas the high-rate data services will mainly be handled by the UMTS network.

5.1 UMTS-to-GSM Service Distribution The UMTS-to-GSM service distribution function corresponds to the feature WRFD-070007 GSM and UMTS Traffic Steering Based on Iur-g. In UMTS-to-GSM service distribution, the users in the UMTS network are handed over to a GSM target cell that is not congested. The UMTS-to-GSM service distribution can be performed in either of the following phases: 

CS service distribution during RRC setup: During the RRC setup, the CS AMR services are redirected to the GSM cell.



Service distribution after RAB setup: After the RAB is set up, the CS or PS services are handed over to the GSM cell.

5.1.1 CS Service Distribution During RRC Setup If the CS service is initiated during the RRC setup stage and the service distribution and load balancing algorithm switch (MBSCServiceDiffLdbSwitch) is set to SERVICE-BASED, the service distribution is performed as shown in Figure 5-1.

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5 Service Distribution

Figure 5-1 UMTS-to-GSM service distribution during the RRC setup

When the RRC is redirected, a GSM candidate cell must meet the following conditions: 

The GSM cell is in operation.



The cell supports the inter-RAT handover for CS services.



The uplink load and the downlink load of the cell are in normal state.

The RNC initiates the redirection to the best GSM candidate cell. If no cell is suitable among the GSM neighboring cells, the UE accesses the UMTS cell.

5.1.2 Service Distribution After RAB Setup After RAB setup, if the service distribution and load balancing algorithm switch (MBSCServiceDiffLdbSwitch) is set to SERVICE-BASED and the Service Handover attribute carried in the assignment request from the MSC is "Handover to GSM should be performed", the service distribution is performed as shown in Figure 5-2.

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5 Service Distribution

Figure 5-2 UMTS-to-GSM service distribution after RAB setup

For single CS/PS services, the RNC selects the cells that meet the following conditions from the neighboring cells, and then sends the measurement control to the UEs so that the UEs perform the 3C event measurement to those cells. 

The GSM cell is in operation.



The cell supports the inter-RAT handover for CS and PS services.



The uplink load and the downlink load of the cell are in normal state.

If any cell meets the 3C event reporting conditions, the UE reports the 3C event to the RNC, and then this cell is taken as a candidate cell. If there are multiple candidate cells, the RNC initiates the handover to the best GSM candidate cell. If no qualified cell is available among the GSM neighboring cells, the UE is retained in the UMTS cell.

5.2 GSM-to-UMTS Service Distribution The GSM-to-UMTS service distribution function corresponds to the feature GBFD-511104 GSM and UMTS Traffic Steering Based on Iur-g. 

If the inter-RAT load handover switch (InterRatServiceLoadHoSwitch) is set to Cn Service-based and the Service Handover attribute carried in the assignment request from the MSC is "handover to UTRAN or cdma2000 should be performed", the BSC imitates the directed retry to the UMTS.



If the inter-RAT load handover switch (InterRatServiceLoadHoSwitch) is set to Service-based, the CS traffic in the GSM system is retained in the GSM cell, avoiding the directed retry from the GSM to the UMTS when the Service Handover attribute is "handover to UTRAN or cdma2000 should be performed".

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5 Service Distribution

If the inter-RAT load handover switch (InterRatServiceLoadHoSwitch) is set to Dynamic Service/Load-based and the load in the GSM cell is in normal state, that is, the uplink load and downlink load are lower than UlLdrThrd2GCell and DlLdrThrd2GCell respectively, the CS traffic in the GSM system is retained in the GSM cell.

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6 Load Balancing

6 Load Balancing The load balancing function corresponds to the feature MRFD-211402 MBSC Load Balancing. In the case of GSM/UMTS co-existence, the traffic loads on the two networks are normally different. For better utilization of the resources in the GSM and UMTS networks, load balancing is introduced to balance the loads between the GSM and UMTS networks, avoiding the situation where one system is overloaded whereas the other one is only lightly loaded. The BSC6900 enables the redirection and handover between the GSM and UMTS systems based on the load condition and difference in each network. In this way, the two networks in the same coverage area can have similar load conditions, reducing the risk of access congestion.

6.1 UMTS Load Balancing The UMTS load balancing function corresponds to the feature WRFD-070006 GSM and UMTS Load Balancing Based on Iur-g. With UMTS load balancing, the CS AMR services and the low-rate PS services are handed over from a UMTS cell to a GSM cell when the GSM cell load is in normal state. The UMTS load balance can be performed in either of the following phases: 

Load balancing during RRC setup: During the setup of the RRC connection, the CS AMR services are redirected to the GSM cell.



Load balance after RAB setup: After the RAB is set up, the single CS or PS services are handed over to the GSM cell.

6.1.1 Load Balance During RRC Setup If the CS AMR service is initiated during the RRC setup stage and the service distribution and load balancing algorithm switch (MBSCServiceDiffLdbSwitch) is set to LOAD-BASED, the service distribution is performed as shown in Figure 6-1. Figure 6-1 UMTS load balance during RRC setup

The RNC selects the GSM neighboring cells that meet the following conditions as candidate cells:

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6 Load Balancing



The GSM cell is in operation.



The uplink load and downlink load in the GSM cell are not in overload congestion state.



The cell supports the inter-RAT handover for CS services.



The load of UMTS source cell minus the load of the cell is higher than the threshold of CS load difference between UMTS and GSM (Mbsc3G2GLdBlcCsDeltaThrd).

The RNC initiates the redirection to the best GSM candidate cell. If no cell is suitable among the GSM neighboring cells, the UE accesses the serving UMTS cell.

6.1.2 Load Balancing After RAB Setup Figure 6-2 UMTS load balancing after RAB setup

If the service distribution and load balancing algorithm switch (MBSCServiceDiffLdbSwitch) is set to LOAD-BASED and the Service Handover attribute carried in the assignment request from the MSC is "Handover to GSM should be performed", load balancing is performed. The RNC selects the cells that meet the following conditions from the neighboring cells, and then sends the measurement control to the UEs so that the UEs perform the 3C event measurement to those cells. 

The GSM cell is in operation.



The uplink load and downlink load in the GSM cell is not in overload congestion state.



For the CS service, the GSM cell supports incoming inter-RAT handover for CS services and the load of UMTS source cell minus the load of the GSM cell is higher than the threshold of CS load difference between UMTS and GSM (Mbsc3G2GLdBlcCsDeltaThrd). For the PS service, the GSM cell supports incoming inter-RAT handover for PS services and the load of UMTS source cell minus the load of the GSM cell is higher than the threshold of PS load difference between UMTS and GSM (Mbsc3G2GLdBlcPsDeltaThrd).

If any cell meets the 3C event reporting conditions, the UE reports the 3C event to the RNC, and then this cell is taken as a candidate cell. If there are multiple candidate cells, the RNC initiates the handover

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6 Load Balancing

to the best GSM candidate cell. If no qualified cell is available among the GSM neighboring cells, the UE is retained in the UMTS cell.

6.2 GSM Load balancing The GSM load balancing function corresponds to the feature GBFD-511103 GSM and UMTS Load Balancing Based on Iur-g. The load balancing can be enabled by setting the inter-RAT load handover switch (InterRatServiceLoadHoSwitch) to Load-based. Based on the load in the target UMTS cells, the UEs in the GSM network are handed over to the UMTS cells. During the call setup, the GSM-to-UMTS load balancing is performed through directed retry, as shown in Figure 6-3. Figure 6-3 GSM load balancing

The BSC performs load balancing when the Service Handover attribute carried in the channel assignment request from the MSC is "handover to UTRAN or cdma2000 should be performed" and the uplink load and the downlink load on the GSM cell that carry the service are not in normal state. The BSC selects the UMTS neighboring cells that meet the following conditions as the candidate cells: 

The UMTS cell is in operation.



The uplink load and downlink load in the UMTS cell is not in overload congestion state.



The load of GSM source cell minus the load of the cell is higher than the threshold of CS load difference between UMTS and GSM (G2G3GLdBlcDeltaThrd).

The BSC initiates the redirection to the best UMTS candidate cell. If no cell is suitable among the UMTS neighboring cells, the UE accesses the GSM cell.

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6 Load Balancing

If the inter-RAT load handover switch (InterRatServiceLoadHoSwitch) is set to Dynamic Service/Load-based and the serving cell is in load congestion, the BSC selects a suitable cell according to the preceding procedure for the UE to access.

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7 NACC Procedure Optimization

7 NACC Procedure Optimization The NACC procedure optimization function corresponds to the feature MRFD-211401 NACC Procedure Optimization, and the feature WRFD-070005 NACC Procedure Optimization Based on Iur-g between GSM and UMTS. To perform NACC in the PS domain, the UMTS cell needs to obtain the system information related to the GSM cell. If the UMTS cell and the GSM cell are operated by the same BSC6900, system information related to the GSM cell can be obtained through internal information transfer rather than through the core network. This reduces the signaling load on the SGSN and makes the cell reselection operation faster. In a common NACC procedure, when the RNC needs to obtain the system information related to a GSM cell, it sends a RAN INFORMATION REQUEST message to the SGSN. The SGSN then identifies the BSC that serves the target GSM cell, and then forwards the message to this target BSC. The response message, RAN INFORMATION, from the BSC is sent to the RNC through the SGSN. The signaling procedure is illustrated in Figure 7-1. Figure 7-1 Normal NACC procedure

In the optimized NACC procedure, the SGSN is not involved. If the UMTS cell and the target GSM cell are operated by the same BSC6900, the RNC sends the INFORMATION EXCHANGE INITIATION REQUEST message to the BSC through an internal message. In addition, the BSC sends the response message through the internal message. The signaling procedure is illustrated in Figure 7-2.

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7 NACC Procedure Optimization

Figure 7-2 Optimized NACC procedure

When using this optimized NACC procedure, provided by the Co-RRM feature, the SGSN is not involved in the NACC procedure, so the execution time for the NACC procedure is reduced. In addition, the signaling load on the SGSN is reduced.

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8 Engineering Guidelines

8 Engineering Guidelines This section provides engineering guidelines regarding the configuration of Co-RRM. For details, see the SingleRAN Feature Activation Guide.

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9 Parameters

9 Parameters Table 9-1 Parameter description Parameter ID

NE

MML Command

Description

CSHOOut2Gloa BSC6900 ADD Meaning: This parameter specifies the threshold for 2G dThd UCELLINTERRATH load of relocation target, in an inter-RAT handover in ONCOV(Optional) CS domain. When the GSM load policy is used, that is, when "NcovHoOn2GldInd" in "SET MOD UCELLINTERRATH UINTERRATHONCOV" is set to ON, a non-coverage-based handover to a 2G cell is stopped ONCOV(Optional) in a non-coverage-based 3G-to-2G handover procedure if the uplink or downlink normalized load carried in the relocation response message from the 2G system exceeds the value of this parameter. GUI Value Range: 0~100 Actual Value Range: 0~1 Default Value: 80 DlLdrThrd2GCe BSC6900 SET Meaning: When the downlink load of a cell is larger ll GCELLHOINTERRA than the value of this parameter and is smaller than TLDB(Optional) "2G Cell DL Overload Congest Thred", the downlink of the cell is in the basic congestion status. GUI Value Range: 1~100 Actual Value Range: 1~100 Default Value: 90 G2G3GLdBlcD BSC6900 SET Meaning: Use this parameter to set Load difference eltaThrd OTHSOFTPARA(Opt threshold for load-based handovers between GSM and ional) UMTS. If the load balance between a 2G cell and a 3G cell is greater than the threshold, load balance is triggered. GUI Value Range: 0~200 Actual Value Range: -100~100 Default Value: 110 InterRatService BSC6900 SET Meaning: When this parameter is set to Service-based, LoadHoSwitch GCELLHOINTERRA the inter-RAT handover is triggered on the basis of the TLDB(Optional) service distribution. In this case, the target cell is selected this parameter is set to Load-based, the inter-RAT handover is triggered on the basis of the load balance. In this case, the target cell is selected according to the traffic load on the target cell and the load difference between 2G and 3G cells. When this parameter is set to Dynamic Service/Load based, the target cell is dynamically selected by using the service-based algorithm or the load-based algorithm according to the traffic load on the cell. When this parameter is set to CN Service-based, the inter-RAT handover decision is made on the basis of the service attribute of the core network.

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SingleRAN Common Radio Resource Management

Parameter ID

NE

MML Command

9 Parameters

Description When this parameter is set to OFF, no inter-RAT service handover or inter-RAT load handover in the access state is performed. GUI Value Range: Service-based(Service-based), Load-based(Load-based), Dynamic-based(Dynamic Service/Load-based), CnService-based(CN Service-based), OFF(OFF) Actual Value Range: Service-based, Load-based, Dynamic-based, CnService-based, OFF Default Value: OFF

LoadHoOn3G2 BSC6900 SET Meaning: If the switch is ON, the load difference GldInd UMBSCCRRM(Optio between 3G cell and target 2G cell will be considered nal) during the load-base handover. If the switch is OFF, the load difference between 3G cell and 2G cell will not be considered. GUI Value Range: OFF(OFF), ON(ON) Actual Value Range: OFF, ON Default Value: OFF Mbsc3G2GLdBl BSC6900 SET Meaning: This parameter defines the load difference cCsDeltaThrd UMBSCCRRM(Optio threshold between 3G cell and 2G cell when CS nal) service is distributed to 2G. If the load difference between 3G cell and target 2G cell exceeds this parameter value, then the load-based balance of CS service may be performed. GUI Value Range: -100~100 Actual Value Range: -100~100 Default Value: 10 Mbsc3G2GLdBl BSC6900 SET Meaning: This parameter defines the load difference cPsDeltaThrd UMBSCCRRM(Optio threshold between 3G cell and 2G cell when PS nal) service is distributed to 2G. If the load difference between 3G cell and target 2G cell exceeds this parameter value, then the load-based balance of PS service may be performed. GUI Value Range: -100~100 Actual Value Range: -100~100 Default Value: 30 MbscNcovHoO BSC6900 SET Meaning: If the switch is ON, the load state of target 2G n2GldInd UMBSCCRRM(Optio cell will be considered during Non-covered InterRat nal) handover procedure. If the switch is OFF, the load state of target 2G cell will not be considered. GUI Value Range: OFF(OFF), ON(ON) Actual Value Range: OFF, ON Default Value: OFF

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SingleRAN Common Radio Resource Management

Parameter ID

NE

MML Command

9 Parameters

Description

MbscServiceDif BSC6900 SET Meaning: This parameter defines the switch of service fLdbSwitch UMBSCCRRM(Optio distribution and load balancing algorithm. If nal) SERVICE-BASED is selected, only load state of 2G target cell will be considered. If LOAD-BASED is selected, the difference between the load in the source cell and load in the target 2G cell will be considered in addition. If DYNAMIC-BASED is selected, it will be automatically adjusted to SERVICE-BASED or LOAD-BASED according the load status of current cell. GUI Value Range: OFF(OFF), SERVICE-BASED(SERVICE-BASED), LOAD-BASED(LOAD-BASED), DYNAMIC-BASED(DYNAMIC-BASED) Actual Value Range: OFF, SERVICE-BASED, LOAD-BASED, DYNAMIC-BASED Default Value: OFF OutSysLoadHo BSC6900 SET Meaning: This parameter specifies whether to allow the En GCELLHOINTERRA inter-RAT load handover in connection mode (after the TLDB(Optional) assignment is complete). GUI Value Range: NO(No), YES(Yes) Actual Value Range: NO, YES Default Value: NO PSHOOut2Gloa BSC6900 ADD Meaning: This parameter specifies the threshold for 2G dThd UCELLINTERRATH load of relocation target, in an inter-RAT handover in ONCOV(Optional) PS domain. When the GSM load policy is used, that is, when "NcovHoOn2GldInd" in "SET MOD UCELLINTERRATH UINTERRATHONCOV" is set to ON, a non-coverage-based handover to a 2G cell is stopped ONCOV(Optional) in a non-coverage-based 3G-to-2G handover procedure if the uplink or downlink normalized load carried in the relocation response message from the 2G system exceeds the value of this parameter. GUI Value Range: 0~100 Actual Value Range: 0~1 Default Value: 60 UlLdrThrd2GCe BSC6900 SET Meaning: When the uplink load of a cell is larger than ll GCELLHOINTERRA the value of this parameter and is smaller than "2G Cell TLDB(Optional) UL Overload Congest Thred", the uplink of the cell is in the basic congestion status. GUI Value Range: 1~100 Actual Value Range: 1~100 Default Value: 90 UlOlcThrd2GCe BSC6900 SET Meaning: When the uplink load of a cell is greater than ll GCELLHOINTERRA the value, the uplink of the cell is in the overload TLDB(Optional) congestion status.

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SingleRAN Common Radio Resource Management

Parameter ID

NE

MML Command

9 Parameters

Description GUI Value Range: 1~100 Actual Value Range: 1~100 Default Value: 100

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10 Counters

10 Counters There are no specific counters associated with this feature.

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11 Glossary

11 Glossary For the acronyms, abbreviations, terms, and definitions, see the Glossary.

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12 Reference Documents

12 Reference Documents [1] Handover Feature Parameter Description of the GBSS [2] Handover Feature Parameter Description of the RAN [3] Interoperability Between GSM and WCDMA Feature Parameter Description of the GBSS

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