Keep Voice Traffic in 3G network is one of strategic optimization in Cellular network. The reasons why should keep traffic in 3G shall be: 2G network Congestion/Blocking issue,2G network problem(HW/issue,Interference) even 2G network will be dismantled.
Today I would like to share Parameter setting to keep voice traffic in 3G due to 2G network Capacity will be decreased caused 4G Network will be deployed and use 2G Bandwidth. 2G will be dismantled due to 4G Network will be implemented so voice traffic will be keep in 3G network and all parameter that previously sharing to 2G will be disabled.
Below are list parameter in 3G Huawei to keep voice traffic in 3G network:
1. Decrease value setting of 2D/2F:
INTERRATCSTHD2DECN0: ex:-14 to -20
INTERRATCSTHD2FECN0: ex:-12 to -18
INTERRATCSTHD2DRSCP ex:-100 to -105
INTERRATCSTHD2FRSCP ex: -97 to - 102
2. Decrease value setting of QQUALMIN ex: -18 to -22
3. Decrease value setting of FDDQMIN ex: -14 to -20(SET GCELLCCUTRANSYS in 2G side)
4. Remove IRATCS in UCELLLDR : CSInterRatShouldNotLDHO/CSInterRatShouldBeLDHO
5. Setting SBHO to OFF : CSSERVICEHOSWITCH=OFF (Command:UCELLHOCOMM)
Detail Parameter can be described as follow:
INTERRATCSTHD2DECN0:
Threshold of triggering inter-RAT measurement for CS services when measurement quantity is Ec/No. The threshold of triggering the inter-RAT measurement (the threshold of enabling the compressed mode) is a key parameter in the inter-RAT handover policy. The setting of this parameter affects the proportion of the UEs in compressed mode in a cell and the success rate of the hard handover. The setting of this parameter should consider two factors, moving speed of the UE and cell radius. When Ec/No is used as the measurement quantity for CS services, the UE reports event 2D when the measured Ec/No value is lower than this threshold. Then, the RNC sends the signaling to enable the compressed mode and start inter-RAT measurement. For the UE moving at a speed of 5 km/h, the recommended threshold is -17 dB; for the UE moving at a speed of 50 km/h, the recommended threshold is -14 dB; for the UE moving at a speed of 120 km/h, the recommended threshold is -12 dB. In actual networks, set this parameter to -14 dB because the UEs in a cell usually move at different speeds. The emulation result shows that the call drop rate remains low for the UEs moving at a speed of 120 km/h when this parameter is set to -14 dB. If the cell is a macro cell, it indicates that micro cells exist in this cell. To enable the micro cells to handle more traffic, the compressed mode start and stop thresholds should be set higher, that is, the thresholds for events 2D and 2F using CPICH RSCP are set higher. If the cell is a micro cell, the default value should be modified according to the link budgeting result. Event 2D and event 2F are used to enable and disable the compressed mode respectively. When the cell is located in the center of the frequency coverage or the inter-frequency measurement quantity uses both Ec/No and RSCP, then the Ec/No value is used as the criterion for events 2D and 2F. To enable the compressed mode earlier, increase the threshold of triggering event 2D; otherwise, decrease the threshold of triggering event 2D. To prevent the frequent enabling and disabling of the compressed mode, increase the difference between the thresholds of triggering event 2D and event 2F. Event 2D and event 2F are used to enable and disable the compressed mode respectively in inter-RAT measurement. The requirements on the signal quality and inter-RAT handover policies vary with the service type. Therefore, the thresholds of enabling and disabling inter-RAT measurement are distinguished by CS, PS, and signaling. To enable the compressed mode earlier, increase the threshold of triggering event 2D; otherwise, decrease the threshold of triggering event 2D. To prevent the frequent enabling and disabling of the compressed mode, increase the difference between the thresholds of triggering event 2D and event 2F.
INTERRATCSTHD2FECN0:
Threshold of stopping inter-RAT measurement for CS services when measurement quantity is Ec/No. The threshold of stopping the inter-RAT measurement (the threshold of disabling the compressed mode) is a key parameter in the inter-RAT handover policy. The setting of this parameter affects the proportion of the UEs in compressed mode in a cell and the success rate of the hard handover. The setting of this parameter should consider two factors, moving speed of the UE and cell radius. When Ec/No is used as the measurement quantity for CS services, the UE reports event 2F when the measured Ec/No value is higher than the value of this parameter. Then, the RNC sends the signaling to disable the compressed mode and stop the inter-frequency measurement. If the cell is a macro cell, it indicates that micro cells exist in this cell. To enable the micro cells to handle more traffic, the compressed mode start and stop thresholds should be set higher, that is, the thresholds for events 2D and 2F using CPICH RSCP are set higher. If the cell is a micro cell, the default value should be modified according to the link budgeting result. Event 2D and event 2F are used to enable and disable the compressed mode respectively. When the cell is located in the center of the frequency coverage or the inter-frequency measurement quantity uses both Ec/No and RSCP, then the Ec/No value is used as the criterion for events 2D and 2F. To enable the compressed mode earlier, increase the threshold of triggering event 2D; otherwise, decrease the threshold of triggering event 2D. To prevent the frequent enabling and disabling of the compressed mode, increase the difference between the thresholds of triggering event 2D and event 2F.
INTERRATCSTHD2DRSCP:
Threshold of triggering inter-RAT measurement for CS services when measurement quantity is RSCP. When RSCP is used as the measurement quantity for CS services, the UE reports event 2D when the measured RSCP value is lower than this threshold. Then, the RNC sends the signaling to enable the compressed mode and start the inter-RAT measurement. To enable the compressed mode earlier, increase the threshold of triggering event 2D; otherwise, decrease the threshold of triggering event 2D. To prevent the frequent enabling and disabling of the compressed mode, increase the difference between the thresholds of triggering event 2D and event 2F. In most cases, users want to be maintained within a 3G network. Therefore, the start threshold of the inter-RAT measurement is set smaller than that of the inter-frequency measurement in order to trigger inter-frequency easily. In scenarios where inter-frequency neighboring cells are unavailable or where inter-frequency coverage is insufficient, the inter-RAT measurement start threshold should be set relatively larger in order to trigger inter-RAT measurement easily, thus reducing call drops.
INTERRATCSTHD2FRSCP:
Threshold of stopping inter-RAT measurement for CS services when measurement quantity is RSCP. When RSCP is used as the measurement quantity for CS services, the UE reports event 2F when the measured RSCP value is larger than this threshold. Then, the RNC sends the signaling to disable the compressed mode and stop the inter-RAT measurement.
QQUALMIN:
Minimum CPICH Ec/No for the neighboring cell on cell reselection. The neighboring cell can be involved in cell sorting for reselection only when its CPICH Ec/No is above this threshold. If this parameter is set to the same value as Qqualmin for the serving cell, Qqualmin is not contained in SIB11 or SIB12. In this case, the UE extracts the Qqualmin from SIB3. For details, see the 3GPP TS 25.331. According to the 3GPP TS 25.304, S criterion for cell reselection is defined as follows: Srxlev > 0 and Squal > 0 Here, Squal = Qqualmeas - Qqualmin Srxlev = Qrxlevmeas - Qrxlevmin - Pcompensation "Qqualmeas" refers to the measured CPICH Ec/No. "Qrxlevmeas" refers to the CPICH RSCP. "Qrxlevmin" refers to the minimum CPICH receive power in the current cell. Pcompensation = max(UE_TXPWR_MAX_RACH - P_MAX, 0) "UE_TXPWR_MAX_RACH", also named as "MaxAllowedULTxPower", refers to the maximum uplink transmit power when the UE accesses a cell. "P_MAX" refers to the maximum RF output power of the UE.
FDDQMIN:
This parameter specifies one of the parameters for FDD cell reselection. A FDD cell becomes a candidate cell if all the following conditions are met for five consecutive seconds: 1.Receive level of the FDD cell > Average receive level of the current serving cell + "FDD Q offset"; The FDD cell meets the following condition in the case of any neighboring 2G cell: Receive level of the FDD cell > Receive level of any neighboring 2G cell + "FDD Q offset"; 2. Ec/No of the FDD cell > "FDD Qmin" - "FDD Qmin Offset"; 3. Receive level of the FDD cell > "RSCP Threshold"; If multiple FDD cells meet the preceding conditions, the MS reselects the cell with the strongest receive level. See 3GPP TSs 45.008 and 25.304. The values of this parameter correspond to the following decibel values: 0: -20 dB, 1: -6 dB, 2: -18 dB, 3: -8 dB, 4: -16 dB, 5: -10 dB, 6: -14 dB, 7: -12 dB.
UCELLLDR:
Remove: CSInterRatShouldNotLDHO/CSInterRatShouldBeLDHO
DL LDR first action-10th/UL LDR first action-8 action:
NOACT: No load reshuffling action is taken. INTERFREQLDHO: The inter-frequency load handover is performed. BERATERED: Channels are reconfigured for the BE service. QOSRENEGO: The renegotiation on the QoS of the uncontrollable real-time service is performed. CSINTERRATSHOULDBELDHO: The inter-RAT SHOULDBE load handover of the CS domain is performed. PSINTERRATSHOULDBELDHO: The inter-RAT SHOULDBE load handover of the PS domain is performed. AMRRATERED (AMR service rate decreasing): The setting of the TFC subset and the negotiation of the service rate can be performed for the AMR voice service. MBMSDECPOWER (MBMS power limiting): The MBMS service is configured with the minimum power. CODEADJ (code tree reshuffling): The fragments of the downlink code tree are arranged. PSINTERRATSHOULDNOTBELDHO: The inter-RAT SHOULDNOTBE load handover of the PS domain is performed. PSINTERRATSHOULDNOTLDHO: The inter-RAT SHOULDNOTBE load handover of the PS domain is performed. The LDR takes the actions in the preset sequence and judges whether each action is successful. If an action is unsuccessful, the LDR turns to the next action. If an action is successful, a parameter is set to NOACT, or all the preceding actions are taken, the downlink LDR is finished, and the system waits for the next triggering of the LDR. Because each action is performed by its algorithm module, the LDR algorithm only selects users and delivers control messages, the execution result of each action can be obtained after a delay, and the LDR algorithm cannot wait for a long time, so the LDR can only judge whether the actions succeed by whether candidate users are found. The inter-frequency load handover has no impact on the QoS of users and can balance the cell load, so the inter-frequency load handover usually serves as the first action. The BE service rate reduction is effective only when the DCCC algorithm is enabled.
Step each command script are as follow:
1. UINTERRATHOCOV(RNC Parameter)
Script:
SET UINTERRATHOCOV:INTERRATCSTHD2DECN0=-20,INTERRATCSTHD2FECN0=-18,INTERRATCSTHD2DRSCP=-105,INTERRATCSTHD2FRSCP=-102;
Fallback:
SET UINTERRATHOCOV:INTERRATCSTHD2DECN0=-14,INTERRATCSTHD2FECN0=-12,INTERRATCSTHD2DRSCP=-100,INTERRATCSTHD2FRSCP=-97;
2. UCELLINTERRATHOCOV(Cells Parameter)
Script:
MOD UCELLINTERRATHOCOV:CELLID=30289,INTERRATCSTHD2DECN0=-20,INTERRATCSTHD2FECN0=-18,INTERRATCSTHD2DRSCP=-105,INTERRATCSTHD2FRSCP=-102;
Fallback:
MOD UCELLINTERRATHOCOV:CELLID=30289,INTERRATCSTHD2DECN0=-10,INTERRATCSTHD2FECN0=-8,INTERRATCSTHD2DRSCP=-90,INTERRATCSTHD2FRSCP=-87;
3. a.UCELLLDR(DL)
Script:
MOD UCELLLDR:CELLID=30639,DLLDRTHIRDACTION=PSInterRatShouldNotLDHO,DLLDRFOURTHACTION=InterFreqLDHO,DLLDRFIFTHACTION=NoAct;
Fallback:
MOD UCELLLDR:CELLID=30639,DLLDRTHIRDACTION=CSInterRatShouldNotLDHO,DLLDRFOURTHACTION=PSInterRatShouldNotLDHO,DLLDRFIFTHACTION=InterFreqLDHO;
3.b.UCELLLDR(UL)
Script:
MOD UCELLLDR:CELLID=30639,ULLDRSECONDACTION=PSInterRatShouldNotLDHO,ULLDRTHIRDACTION=InterFreqLDHO,ULLDRFOURTHACTION=NoAct
Fallback:
MOD UCELLLDR:CELLID=30639,ULLDRSECONDACTION=CSInterRatShouldNotLDHO,ULLDRTHIRDACTION=PSInterRatShouldNotLDHO,ULLDRFOURTHACTION=InterFreqLDHO;
4. UCELLHOCOMM
Script:
MOD UCELLHOCOMM: CellId=39251, CSSERVICEHOSWITCH=OFF;
Fallback:
MOD UCELLHOCOMM: CellId=39251, CSSERVICEHOSWITCH=ON;
Above parameter mentioned are valid only for Huawei Network because we are in Huawei project.
Hope can use full for you who want to know deep about keeping voice traffic in 3G instead of 2G network for voice quality improvement.
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