TCH Block Rate Optimization Tips in Huawei GSM

TCH Block Rate is familiar KPI in GSM Networks. TCH Block rate indicate percentage of blocking on TCH(Traffic channel) due to lack of traffic channel in a cell. In this note I would like to share how to optimize TCH Bloking rate step by step in order to reduce TCH blocking and configure channel capacity based on traffic needed. Below are steps you need to follow based on my daily optimization activity in my project in Indonesia.

• Check for hardware, make sure no hardware issue.

Hardware checking always the first thing you need to check. You have to make sure no hardware issue before go to next optimization step.Your next action will be useless if the problem of the KPI is hardware issue.If found hardware issue please follow up first to FLM(Field Maintenance) or Project Team to check and troubleshoot. You can check from active alarm and especially from TCH Availability to make sure no TRX module faulty. If found no hardware issue then go to next step.

• Check for Coverage, make sure no Overshooting

Coverage also need to check to make sure no overshooting and cover so far area that will trigger TCH Blocking due to cover unnecessary location and huge traffic.If found overshooting then you need to adjust Antenna tilt.If found no problem with coverage the go to next step.

• Check for Current Channel Configuration, make sure no over dimension of other channel(SDCCH, BCH and PDTCH)

Current channel configuration need to check to make sure no over dimension of other channel(ex:SDCCH,BCH or PDTCH). For SDCCH You can refer to number of TRX, usually the number of SDCCH in a cell same as number of TRX on that cell(ex: number of SDCCH =2 if TRX number =2), except for other case such as high SD traffic cell or covering Event, number of SDCCH may be different. for BCH usually maximum 2 channel in 1 Cell. and for PDTCH usually 1 static PDTCH for 1 TRX(same as SDCCH),except for high PS Traffic cells. After make sure no over dimension channel of other channel(beside TCH), then go to next step

• Calculate TCH needed based on Erlang B Calculation

Now you need to generate measurement related TCH Traffic maximum on the Cell then calculate besed on Erlang B Table. After get TCH Traffic measurement on Busy Hour Cells then you can calculate how many channel needed to accommodate TCH traffic. Click here to calculate channel required for TCH based on Erlang B calculation.

• Change Half Rate Threshold/Re-Dimension Channel/Upgrade TRX

Based on Elang B calculation now you get how many channel TCH needed to accommodate traffic on TCH. Then you can go to Upgrade or Change other Channel into TCH or Change Half Rate setting(TCHBUSYTHRES/AMRTCHPRIORLOAD in Huawei Parameter).You can go to upgrade TRX if Half rate setting already maximum(TCHBUSYTHRESS=0) and additional channel required need add TRX ( 1 TRX = 8 Channel TCHFR) and also no possibility to change other channel into TCH.

Summary to Optimize TCH Block rate:
- Check Hardware problem, make sure no hardware problem occurred.
- Check Coverage, make sure no overshooting to avoid cells cover unnecessary traffic/Covering far area.
- Check Channel Configuration, make sure no over dimension of other channel(SDCCH, BCH and PDCH)
- Calculate TCH Needed based on Erlang B Calculation
- Change Half Rate Setting(TCHBUSYTHRESS and AMRTCHPRIORLOAD)/Channel re-dimension(Change other channel into TCHFR)/Upgrade TRX

You might also Need to know:
- 2G Voice Quality improvement by TRX Layering Priority
- TBF Drop Improvement tips in Huawei GSM
- GPRS Packet Data Access Rate(PDASR) Improvement in Huawei GSM
- Call Drop Rate Improvement by Parameter change in 3G Huawei

2G Voice Quality Improvement by TRX Layering priority in Huawei GSM

Voice Quality is still become priority in GSM Network While 3G UMTS/WCDMA and 4G LTE focus on Data Packet Services. In this Optimization tips I would like to share how to improve voice quality in GSM Huawei Network based on my experiences in Huawei project in Indonesia.
The Idea to improve Voice quality is by prioritizing voice services in Good TRX. Good TRX means TRX which have less frequency interference and Good TRX module than other TRX in one cell. We can improve quality of Voice services by shifting voice traffic concentrated to a good TRX. Good TRX usually located in BCCH TRX because frequency has more clear and Full Power(No Power control on BCCH TRX). So in this case assume good TRX is BCCH TRX(you can choose other TRX if good TRX are different in your Network).The things that you can prepare are as follow:
1. Do redimensioning channel(Shifting PDTCH Channel to non BCCH TRX)
First action you need is moving data channel(static PDCH)  to TRX non BCCH to make sure voice services concentrated in BCCH TRX and other services(PS) handle by other TRX(non BCCH TRX). So in this case PS services is not our priority. We just concentrated to improve Voice services in 2G Network, while PS Services throw handled by 3G Network. The script you need to provide for redimensioning channel by shifting static PDTCH to non BCCH TRX are as follow:

2. Make Priority for TRX BCCH to handle Services by setting GTRXDEV
Second action you need to do is make priority for TRX BCCH to handle services than other TRX.
By this setting Voice services will be concentrated in TRX BCCH(assumed good TRX) and PS services will be in TRX non BCCH. Parameter setting for this action is by setting OPTL to higher value for non BCCH TRX(ex: L0 change to L1). Here are sample of Parameter change for this action:

Detail of parameter:
OPTL: This parameter specifies the TRX priority in channel assignment. The smaller this parameter is, the higher the TRX priority is. For two TRXs with other conditions identical, channels on the TRX with higher priority are preferentially assigned.

By setting OPTL to L1 for TRX non BCCH means you make low priority for TRX non BCCH to handled the services.

Those above step you can try in your GSM Huawei Network to improve Voice Quality Services and also will improve Drop Call Rate in your Network.
You might also Need to know:
- Drop Call Rate Optimization tips in GSM and UMTS/WCDMA
- Trial of Power Control in GSM Huawei for Quality Improvement
- Call Drop Rate improvement by Parameter change in 3G UMTS/WCDMA Huawei Network
- TBF Drop Improvement tips in Huawei GSM

TBF Drop Improvement tips in Huawei GSM

TBF drop is KPI(Key Performances Indicator) which is related to 2G data call GPRS/EDGE in GSM Network. TBF drop indicate how often your services disconnected when you in GPRS or EDGE data Services. There are some tips how to improve TBF drop rate in GSM Huawei. You can follow below steps to improve TBF Drop Rate in GSM Huawei.
- Make sure no Hardware problem especially related TRX module. You need to fix Hardware issue first if you found hardware problem
- Make sure no Interference. You have to do re-tune or change frequency that suspected Frequency Interference to improve TBF drop rate
- Make sure No overshooting Cells. You can adjust Antenna Tilt/Down tilt for overshooting cells to improve TBF drop rate and avoid access traffic in low RX level thus can improve TBF drop call.
- Reduce Dynamic PDCH(MAXPDCHRATE) and add static PDTCH to avoid preemption channel by voice services especially for cells with high Voice traffic.
-Shifting Static PDCH from TRX non BCCH to TRX BCCH and make priority setting by set TRX layering priority which can be set by OPTL value in GTRXDEV object.With this strategy data services will be concentrated in TRX BCCH with full power(no power control) thus can improve TBF drop rate and getting better than data services in TRX non BCCH.
- Increase timer T3168 and T3192
T3168 is used to set the maximum duration for the MS to wait for the uplink assignment message. After the MS originates the uplink TBF setup request by sending the packet resource request or the channel request in the packet uplink acknowledge message, the timer T3168 is started to wait for the packet uplink assignment message on the network side. If the MS receives the packet uplink assignment message before T3168 expires, T3168 is reset. Otherwise, the MS originates the packet access request for four times. Then the MS regards this as the TBF setup failure.
T3192: Duration of releasing the TBF after the MS receives the last data block. When the MS receives the RLC data block containing the flag identifying the last data block and confirms that all the RLC data blocks in the TBF are received, the MS sends the packet downlink acknowledge message containing the last flag acknowledgement and the timer T3192 is started. If the timer T3192 expires, the MS releases the TBF related resources and starts monitoring the paging channel. During TBF releasing, if the MS is the half duplex mode and receives the packet uplink assignment, the MS responds this command. During TBF releasing, if the MS is the half duplex mode and receives no packet uplink assignment message, the MS enters the packet idle mode. If the MS is in the dual transmission mode, the MS enters the special mode.
- Increase timer N3101,Ex: from 30 to 90
Detail description of N3101:
Maximum value of the N3101 counter. In the dynamic uplink allocation mode, the network side enables multiple MSs to share the same uplink channel through the USF value in the downlink data block. After the network side allocates the USF to the uplink TBF (the uplink TBF is set up successfully), N3101 is started. The network side waits for the RLC uplink data block sent by the MS. If the RLC uplink data block sent by the MS is valid, N3101 is reset. Otherwise, the value of N3101 is increased on the network side. When this counter is overflowed, the current uplink TBF is released abnormally.
- Increase timer N3103 and N3105
Detail description of N3103 and N3105
N3103: Maximum value of the N3101 counter. When the uplink transmission ends, if the network side receives the last RLC data block, the network side sends an FAI=1 uplink packet  acknowledged/unacknowledged message and starts N3103. If the packet control acknowledgement message is not received in the specified time, N3103 is increased on the network side and the uplink packet  acknowledged/unacknowledged message is retransmitted. When this counter is overflowed, the timer T3169 is started. After this timer expires, the current TBF is released abnormally.
N3105: Maximum value of the N3105 counter. After the downlink TBF is set up successfully, the N3105 is started on the network side. After the downlink RLC data block is added with the RRBP domain on the network side, the valid packet acknowledged message responded by the MS is received in the uplink RLC data block in the RRBP domain. In this case, N3105 is reset. Otherwise, the value of N3105 is increased and the downlink data block of the RRBP is retransmitted. When N3105 is overflowed, T3195 is started. After the timer T3195 expires, the current TBF is released abnormally.
- Change LQC(Link Quality Control Mode) from IR to LA 
LQC Detail description: 
It is applicable to the radio transmission environment to improve the link quality. Link adaptation (LA) indicates adjusting the coding mode of the channel dynamically according to the transmission quality of the link. The link transmission quality is measured by the 8PSK MEAN BEP and 8PSK CV BEP in the Packet EGPRS Downlink Ack/Nack message sent by the MS. The network side determines the coding mode for data transmission according to the radio measurement report sent by the MS. The cell with the good transmission quality on the air interface is set to the LA mode. Increment redundancy (IR) mode requires the network side retransmit the data block with different punching codes and the MS store the historical error information. The data block is retransmitted through cooperated error correction function. With the IR mode, the transmission quality on the air interface of the cell can be improved. However, the MS must support this IR mode. The cell with the dissatisfied transmission quality on the air interface is set to the LR mode.

Thanks for read this note,You can share your suggestion how to improve TBF drop rate in GSM  Network based on your experiences by add comment.

You might also Need to know:
- GPRS Packet Data Access Success Rate(PDASR) Improvement in Huawei GSM
- Call Drop Rate improvement by Parameter change in 3G UMTS/WCDMA Huawei Network
- Drop Call Rate Optimization tips in GSM and UMTS/WCDMA
- WCDMA CSSR Optimization Tips

GPRS Packet Data Access Success Rate(PDASR) Improvement in Huawei GSM

PDASR(Packet Data access Success Rate) also called TBF Success rate indicate Success percentage of Data call GPRS in GSM. This KPI is familiar in Indonesia especially in Hutchison Operator(HCPT) project if you work there for 2G GSM Enginer. In this note I would like to share how to improve Packet Data access Success rate(PDASR) in Huawei GSM Network.Please follow below step to improve PDASR.
Step 1: Check for PDCH Blocking or TBF Blocking due to No channel
PDCH Blocking indicate insufficient data channel for EDGE/GPRS services.For PDCH Blocking you can check also by counter TBF Blocking due to no channel. If you found TBF Blocking then you need to add Channel allocation for Data or you can add static PDCH channel and finally you need to upgrade TRX if found high PDCH blocking. Before propose upgrade TRX you need to change below parameter to improve PDASR.
-Increase MAXPDCHRATE to maximum value: ex: change to 90.
-Increase UPDYNCHNTRANLEV to maximum: 70
-Increase DWNDYNCHNTRANLEV to maximum: 80
-Increase PDCHDWNLEV to 160
-Increase PDCHUPLEV to 70
-Increase DNTBFRELDELAY 
-Increase UPEXTTBFINACTDELAY
- Reduce PSServiceBusyThreshold to 10(give impact to low throughput)

Step 2: Check for TBF fail due to MS no response
TBF fail due to MS no response(UL/DL) occurred on cells due to some reasons such as: Frequency interference,Overshooting Cells or hardware problem.You need to check and clear Frequency interference,overshooting and hardware issue include transmission problem. If after check no problem such as mentioned the you need to optimize by parameter as below recommendation.
- Set DNDEFAULTMCS to MCS3(Give negative impact to DL PS throughput will be decreased)
- Set QUICKSTARTDLTBFONDL to ON(BSC Parameter), Give negative impact to increase of DL TBF drop rate
- Set QUICKSTARTDLTBFONUL to ON(BSC Parameter), Give negative impact to increase of DL TBF drop rate.

Don't forget to check initial step such as: Hardware, Overshooting, Frequency interference to improve all KPI include PDASR(Packet Data Acces Success Rate).

You might also Need to know:
- How to optimize Handover Success Rate(HOSR) in GSM Network
- Drop Call Rate improvement in 3G WCDMA by Parameter
- WCDMA CSSR Optimization tips
- Power Control Tril in GSM Huawei for Quality Improvement

Call Drop Rate improvement by Parameter change in 3G UMTS/WCDMA Huawei Network

Call drop rate in 3G WCDMA is important thing to optimize in our Network. There are many ways to improve drop call such as hardware problem detection, Fix Coverage overlapping, Fix Missing neighbor and Parameter changing. You can refer to previous chapter about  Drop Call Rate Improvement to know step by step about call drop reasons and optimization. What I want to share now is about how to improve drop call rate in 3G UMTS/WCDMA by Parameter adjustment. Before go to the topic we need to know call drop reasons in 3G UMTS:

- High Interference : As we know in that 3G UMTS/WCDMA is self interference because only use 1 frequency and differentiated by Scrambling Code(SC).

- Pilot pollution :Happened due to Coverage overlapping.You need to make sure first no coverage overlapping and can be solved by Physical optimization(Antenna down tilt).

- Missing Neighbor: Make sure no missing neighbor in your network to improve drop call before you start with Parameter optimization.

- Hardware problem: You need to fix first if you found hardware issue.

After you clear main issue for above reasons then you can go to Parameter optimization to reduce drop call rate. Here are recommended Parameter to reduce call drop rate in 3G UMTS/WCDMA for Huawei Network. If you work for other Vendor you can refer to your document and looking for same Parameter.
1. Increase HOASUTMR

HOASUTMR meaning HO active set update response timer, A timer to RNC wait for the response to active set update in soft handover procedure. You can improve call drop in 3G by increase this parameter.

2. Increase Parameter 2D/2F

The idea of this parameter setting is to make fast Handover to GSM network. You can increase 2D/2F parameter and improve your drop call in 3G by moving traffic to GSM network. 

Detail parameter need to be changed are as follow:
- INTERRATCSTHD2DECN0, ex: Change from -14 to -12

- INTERRATCSTHD2FECN0, ex: Change from -12 to -10

- INTERRATCSTHD2DRSCP, ex: Change from -100 to -98

- INTERRATCSTHD2FRSCP, ex: Change from -97 to -95

- INTERRATHTHD2DECN0, ex: Change from -15 to -12

- INTERRATR99PSTHD2DECN0, ex: Change from -15 to -13

- INTERRATHTHD2FECN0, ex: Change from -13 to -10

- INTERRATR99PSTHD2FECN0, ex: Change from -13 to -10

- INTERRATHTHD2DRSCP,  ex: Change from -100 to -95

- INTERRATR99PSTHD2DRSCP,  ex: Change from -100 to -95

- INTERRATHTHD2FRSCP,  ex: Change from -107 to -105

- INTERRATR99PSTHD2FRSCP,  ex: Change from -107 to -105

Description and meaning of Above Parameter can be described as below detail:
- INTERRATCSTHD2DECN0: 

Threshold to trigger inter-RAT measurement with measurement quantity of Ec/No for CS domain services

Value range: -24~0

Physical unit: dB

Content: For CS domain services, when Ec/No is used as the measurement quantity for inter-RAT measurement, the RNC sends the signaling to activate compressed mode and start inter-RAT measurement, if the UE reports the event 2D when the measured value is smaller than the value of this parameter.

Recommended value (default value): -14

- INTERRATCSTHD2FECN0

Threshold to stop inter-RAT measurement with measurement quantity of Ec/No for CS domain services 

Value range: -24~0

Physical unit: dB

Content: For CS domain services, when Ec/No is used as the measurement quantity for inter-RAT measurement, the RNC sends the signaling to deactivate compressed mode and stop inter-RAT measurement, if the UE reports the event 2F when the measured value is larger than the value of this parameter. 

Recommended value (default value): -12

- INTERRATCSTHD2DRSCP

Threshold to trigger inter-RAT measurement with measurement quantity of RSCP for CS domain services 

Value range: -115~-25

Physical unit: dBm

Content: For CS domain services, when RSCP is used as the measurement quantity for inter-RAT measurement, the RNC sends the signaling to activate compressed mode and start inter-RAT measurement, if the UE reports the event 2D when the measured value is smaller than the value of this parameter. 

Recommended value (default value): -100

- INTERRATCSTHD2FRSCP

Threshold to stop inter-RAT measurement with measurement quantity of RSCP for CS domain services 

Value range: -115~-25

Physical unit: dBm

Content: For CS domain services, when RSCP is used as the measurement quantity for inter-RAT measurement, the RNC sends the signaling to deactivate compressed mode and stop inter-RAT measurement, if the UE reports the event 2F when the measured value is larger than the value of this parameter. 

Recommended value (default value): -97

- INTERRATHTHD2DECN0

Threshold to trigger inter-RAT measurement with measurement quantity of Ec/No for PS domain HSPA services 

Value range: -24~0

Physical unit: dB

Content: For PS domain HSPA services, when Ec/No is used as the measurement quantity for inter-RAT measurement, the RNC sends the signaling to activate compressed mode and start inter-RAT measurement, if the UE reports the event 2D when the measured value is smaller than the value of this parameter. 

Recommended value (default value): -15

- INTERRATR99PSTHD2DECN0

Threshold to trigger inter-RAT measurement with measurement quantity of Ec/No for PS domain R99 services 

Value range: -24~0

Physical unit: dB

Content: For PS domain R99 services, when Ec/No is used as the measurement quantity for inter-RAT measurement, the RNC sends the signaling to activate compressed mode and start inter-RAT measurement, if the UE reports the event 2D when the measured value is smaller than the value of this parameter. 

Recommended value (default value): -15

- INTERRATHTHD2FECN0

Threshold to stop inter-RAT measurement with measurement quantity of Ec/No for PS domain HSPA services 

Value range: -24~0

Physical unit: dB

Content: For PS domain HSPA services, when Ec/No is used as the measurement quantity for inter-RAT measurement, the RNC sends the signaling to deactivate compressed mode and stop inter-RAT measurement, if the UE reports the event 2F when the measured value is larger than the value of this parameter. 

Recommended value (default value): -13

- INTERRATR99PSTHD2FECN0

Threshold to stop inter-RAT measurement with measurement quantity of Ec/No for PS domain R99 services 

Value range: -24~0

Physical unit: dB

Content: For PS domain R99 services, when Ec/No is used as the measurement quantity for inter-RAT measurement, the RNC sends the signaling to deactivate compressed mode and stop inter-RAT measurement, if the UE reports the event 2F when the measured value is larger than the value of this parameter. 

Recommended value (default value): -13

- INTERRATHTHD2DRSCP

Threshold to trigger inter-RAT measurement with measurement quantity of RSCP for PS domain HSPA services 

Value range: -115~-25

Physical unit: dBm

Content: For PS domain HSPA services, when RSCP is used as the measurement quantity for inter-RAT measurement, the RNC sends the signaling to activate compressed mode and start inter-RAT measurement, if the UE reports the event 2D when the measured value is smaller than the value of this parameter. 

Recommended value (default value): -110

- INTERRATR99PSTHD2DRSCP

Threshold to trigger inter-RAT measurement with measurement quantity of RSCP for PS domain R99 services 

Value range: -115~-25

Physical unit: dBm

Content: For PS domain R99 services, when RSCP is used as the measurement quantity for inter-RAT measurement, the RNC sends the signaling to activate compressed mode and start inter-RAT measurement, if the UE reports the event 2D when the measured value is smaller than the value of this parameter. 

Recommended value (default value): -110

- INTERRATHTHD2FRSCP

Threshold to stop inter-RAT measurement with measurement quantity of RSCP for PS domain HSPA services 

Value range: -115~-25

Physical unit: dBm

Content: For PS domain HSPA services, when RSCP is used as the measurement quantity for inter-RAT measurement, the RNC sends the signaling to deactivate compressed mode and stop inter-RAT measurement, if the UE reports the event 2F when the measured value is larger than the value of this parameter. 

Recommended value (default value): -107

- INTERRATR99PSTHD2FRSCP

Threshold to stop inter-RAT measurement with measurement quantity of RSCP for PS domain R99 services 

Value range: -115~-25

Physical unit: dBm

Content: For PS domain R99 services, when RSCP is used as the measurement quantity for inter-RAT measurement, the RNC sends the signaling to deactivate compressed mode and stop inter-RAT measurement, if the UE reports the event 2F when the measured value is larger than the value of this parameter. 

Recommended value (default value): -107

Thanks for reading Call Drop Rate improvement by Parameter change in 3G UMTS/WCDMA Huawei, hope can help you best network.

You might also Need to know:

- Drop Call Rate Optimization step in GSM and UMTS

- WCDMA CSSR Optimization tips

- Trial Power Control in GSM Huawei for Quality Improvement

- How to optimize Handover Success Rate(HOSR) in GSM Network

Trial Power Control in GSM Huawei for Quality Improvement

Power Control in GSM is important in optimization strategy to improve quality and reduce interference also to Optimize Drop Call Rate. In this note I would like to share GSM power control trial in Huawei for different clutter.Here are characteristic and scenario for each clutter:
>Urban Scenario:
Characteristic: High Intra Network Interference and tight distance between sites
>Suburban Scenario:
Characteristic: Lower Intra network interference and loose distance between sites
>Fast Moving Scenario:
Characteristic: Fast Moving of MS , the speed more than 50 km/h
>High Power Down scenario:
Characteristic: Strongly requirement to reduce transmit power. User beside BTS will use minimum transmit power. The voice quality will have risk to decrease/degraded.

Configuration of parameter for each clutter describe as below.
>Parameter GSM Power control setting for Urban Scenario:
Based on result of the trial, setting GSM Power control with below value has improve the Quality and reduce interference effectively.

>Parameter GSM Power Control setting for Suburban Scenario
Parameter configuration of power control in GSM for suburban area to improve Quality and reduce TX power almost mainly same parameter setting with Urban scenario,but different for below value:

> Parameter GSM Power Control setting for Fast Moving Scenario
Parameter configuration setting for Fast Moving scenario is applied for High way are/Major road with vehicle speed >50 km/h. Main parameter follow Urban clutter except different for below parameter:

> Parameter GSM Power Control setting for High Power Down scenario
GSM Power control setting for high Power down scenario will impact The transmit power of the MS reduce to the minimum value even The MS located near BTS, but quality may decrease. Parameter setting value also same with Urban setting except for below parameter:

Thanks for reading my note about Trial Power Control in GSM Huawei for Quality Improvement.
You might also Need to know:
- Power Control activation for Electricity Saving in Huawei GSM
- How to optimize Handover Success Rate(HOSR) in GSM Network
- CSSR Optimization for GSM and WCDMA
- Drop Call Rate Optimization in GSM and UMTS

Power Control activation for Electricity Saving in Huawei GSM

Power Control is needed to activate in GSM to save Battery consumption of BTS. What I would like to share is about Electricity saving feature implementation in Huawei GSM. This feature is purposed to save battery consume to reduce Electricity bill especially during low traffic. The goal of this feature is to shut down TRX during low traffic and turn on during traffic going to high.The feature is named TRX Power Amplifier intelligent shutdown

Description of TRX Power Amplifier intelligent shutdown

The TRX Power Amplifier Intelligent Shutdown function can be enabled during a specific period. After this function is enabled, idle TRXs can be shut down to reduce power consumption when estimated traffic load is light, and disabled TRXs can be switched on so that they are available for use when estimated traffic load is heavy.

When the BCCH TRX participates in baseband FH, the cell TRX cannot be shut down. Thus, the TRX power amplifier intelligent shutdown can't be used.

Before configuring Allow Shutdown of TRX Power Amplifier on the TRX, ensure the TRX meets the following conditions:

 >The TRX is not on the BCCH.

 >The Static PDCH is not available on the TRX.

At least two QTRUs or GRFUs need to be configured to support this feature.

Figure description of intelligent shutdown TRX Power Amplifier :

To activate this feature we need to run script in BSC, Cell and TRX Level. Before run the script make sure to reconfigure/dimension Static PDCH on TRX non BCCH because script on TRX level will be failed if there are static PDCH exist on the channel. So you need to shift static PDCH to TRX BCCH or just to change CHTYPE on TRX non BCCH from static PDCH to TCHFR.After that you can run main script to activate feature of Intelligent shutdown TRX. Below are script need to be run if you want to activate intelligent shutdown TRX Power Amplifier in Huawei GSM:

Activation Script :

BSC Level:

SET BSCDSTPA:BSCDYNSWITCHTRXPAALLOW=YES,STARTTIMETACLOSETRXPA=00&00,ENDTIMETACLOSETRXPA=23&59,PROTECTTIMETRXPOWERON=300,RSVIDLECHANNUM=2;

Cell Level:

SET GCELLBASICPARA:IDTYPE=BYID,CELLID=XXXX,DYNOPENTRXPOWER=YES;

TRX Level(non BCCH)

SET GTRXDEV: TRXID=XXXX, CPS=YES;

Deactivation Script :

BSC Level:

SET BSCDSTPA:BSCDYNSWITCHTRXPAALLOW=NO;

Cell Level:

SET GCELLBASICPARA:IDTYPE=BYID,CELLID=XXXX,DYNOPENTRXPOWER=NO;

TRX Level:

SET GTRXDEV: TRXID=XXXX, CPS=NO;

You might also Need to know:
- How to Optimize Handover Success Rate in GSM Network
- WCDMA CSSR Optimization Tips

- CSSR Optimization for GSM
- Drop Call Rate Optimization in GSM and UMTS

Handover Meaning in GSM and How to Optimize Handover Success Rate (HOSR) for GSM KPI Improvement

Handover in GSM is very important to keep continuous of call communication. In this note I would like to share about GSM handover and how to optimize Handover Success Rate(HOSR) in GSM Network based on my knowledge and experiences. Sorry I don't tell you based on document because too much reference. You can refer to your document in your vendor if you want to learn detail based on document.
- Handover definition
Handover meaning call moving between cells to continue conversation and prevent drop call on the Network. Handover also purposed to improve services performances and reduce congestion in the cells.
-Types of handover in GSM
Based on reason type of handover in GSM can be classified as below
1. Emergency Handover : Timing Advance(TA) Handover, Bad Quality Handover,RxLevel Drop handover and Interference Handover
2. Load Handover
3. Normal Handover: Edge Handover, Layer Cell Handover and Power Budget(PBGT) handover
4. Fast Moving Handover
5. Overlaid/Underlaid Handover
Based on location type of Handover can be listed as follow:
1. Intra cell handover : Handover that happened between channel/ TRX in one cell
2. Inter cell Handover : Handover that happened between cell(ex: HO from cell A to Cell B)
3. Intra BSC Handover: Handover between cells in same BSC(ex: HO from cell A to Cell B, A and B located in same BSC)
4. Inter BSC Handover:Handover between cells in different BSC(ex: HO cell A to Cell B, A and B located in different BSC)
5. Handover Inter MSC: Handover that happened between cells but different MSC
For the details about handover process,protocol and rule of each handover type, you can refer to your document in your vendor. In this paper I just want to share step by step how to optimize Handover Success Rate to improve your KPI based on what usually I do. Lets follow below step to optimize Handover.
Step 1: Killing Hardware issue
Hardware issue always the first step to check. As I said before in this blog, to improve all KPI Such as CSSR, Drop Call Rate, HOSR, TCH Blocking,etc always to make sure first no hardware issue occurred. Your next action will be useless if hardware issue occurred in your cells. To identify hardware issue in the cells related handover you can generate measurement related Incoming Handover.After generate measurement you will find which cells have high handover failure.
You can check related cells that have high handover failure and low HOSR and troubleshoot one by one. To troubleshoot hardware issue you can collaborate with FM(Field Maintenance) Team. Make sure no TRX faulty or Combiner problem or event connector problem. If the problem suspected only one cell/sector in 1 site, you can try swap each module to other sector and let see if the problem move to other sector.If the problem happened in all sector in 1 site then you can try swap transmission module(GTMU, IDU, ODU) to other site and let see if handover Incoming failure move to other site. Don't forget to check by drive test to make sure no cross feeder problem occurred in the site.
Step 2: Clearing Frequency Interference
Frequency interference will take effect to all KPI in GSM including Handover Success Rate. You have to make sure no Co-channel /Adjacent channel Interference. Change Frequency of the cells(retune) if you found cells suspected frequency interference.
Step 3: Neighbor list checking and external discrepancy fixing
Check neighbor list in the cells and make sure no missing neighbor. You need to remove unnecessary relation and add necessary relation. Make sure head to head cells have relation(no missing). Your Handover will improve if neighbor list configure properly.Don't forget to check external neighbor value and make sure no discrepancy with existing such as: LAC,BSIC,BCCH and RAC
Step 4: Coverage Checking
Coverage will take effect to Handover performances. You need to make sure no coverage issue, No overshooting cells and coverage is continuous.Propose add site if needed to improve coverage or physical optimization(Down tilt/Up tilt/re-azimuth) to improve your coverage.
Step 5: Check BA List
BA list indicate your neighbor list. Too many measurement frequencies in the active BA list will make you handover bad and you need to remove unnecessary relation.
Step 6: Check for Congestion Problem
Handover Success Rate will be also influenced by congestion on target cells. Make sure no congestion on target cells to improve your HOSR(handover Success Rate).You can minimize congestion by adjust half rate setting in the cells(ex:TCHBUSYTHRES and AMRTCHHPRIORLOAD in Huawei) or Traffic sharing to other cells by parameter or physical optimization
Step 7: Parameter Handover Optimization
The final step to improve Handover Success Rate is Parameter tuning. You need to change some parameter related handover to improve HOSR. The idea is to reduce fail of handover to specific cells and increase successful attempt to several targeted cells. Some parameter can be adjusted such as: PBGT margin, RXLevmin Cell etc.You can refer to your document in your vendor to change specific parameter but keep in mind the idea is to reduce handover fail to specific cells and increase successful attempt to specific targeted cells.For example if you have cell with low handover Success rate(HOSR) due to high attempt to targeted congestion cell or problematic cells, you need to adjust HO PBGT margin or increase RXlevmin to target cell. This idea is purposed to improve HOSR KPI based on statistic to achieve agreed KPI target.

Thanks for reading my note about Handover in GSM, hope can help your daily optimization activity to improve your GSM handover Success rate.

You might also Need to know:
- Power Control activation for Electricity Saving in Huawei GSM
- WCDMA CSSR Optimization Tips

- CSSR Optimization for GSM
- Drop Call Rate Optimization in GSM and UMTS

WCDMA CSSR Optimization Tips

In this paper I would like to share how to improve Call set up Success Rate in WCDMA system.

In WCDMA CSSR is split per services such as: CSSR CS(Voice services), CSSR PS(Data services), CSSR Video(Video services) but the idea is same when we would like to improve Call set up success rate.

Here are some tips how to improve CSSR in WCDMA:

- Make sure no Blocking resources: Code,Power,CE,IUB

As we know in 3G WCDMA there are some resources like Code,Power,CE(Channel Element) and IUB. You have to make sure no blocking resources first to improve your CSSR. If you found some blocking based on your counter then you have to optimize. Here are some suggestion step to optimize blocking resources:

1. Code Blocking Optimization step:

1st action step: Physical Audit (involving TP analysis) : Make sure no overlap/overshooting coverage

2nd Action: Modify DLHOCECODERESVSF to lower SF (e.g from SF32 to SF 64)

3rd Action: Reduce HSPDSCHMINCODENUM (e.g from 5 to 4)

4th Action: Reduce HSSCCHCODENUM (e.g from 4 to 3)

2. Power Blocking Optimization Step:

- UL- Power Blocking

1st Action: Physical Audit (involving TP analysis)

2nd Action: Increase ULTOTALEQUSERNUM (e.g from 160 to 180)

3rd Action: Turn-off NBMULCACALGOSELSWITCH (set to ALGORITHM_OFF)

- DL- Power Blocking/DL - Power High Util

1st action: Physical Audit (involving TP analysis)

2nd Action: Activate 40W, maintain existing PCPICH setting

Step activate 40W in Huawei System:

- Block board with script: BLK BRD:CN=1,SRN=4,SN=x;

- Remove Locell  for 2nd carrier in nodeb with script : RMV LOCELL:LOCELL=x;

- Add Locell on 2nd carrier with script: 

ADD LOCELL:LOCELL=x,STN=x,SECN=x,SECT=LOCAL_SECTOR,ULGROUPNO=0,DLGROUPNO=0,TTW=FALSE,CN1=1,SRN1=4,SN1=x,ANT1N=ANTB,ULFREQ=9638,DLFREQ=10588,MXPWR=460,HISPM=FALSE,RMTCM=FALSE,VAM=FALSE;

- Modify Power to 40 W for 1st carrier with script: MOD LOCELL:LOCELL=x,SECT=LOCAL_SECTOR,MXPWR=460;

- Unblock Board with script: UBL BRD:CN=1,SRN=4,SN=x;

- Modify MAXTXPOWER  in RNC level for F1 dan F2 with script: MOD UCELL:CELLID=x,MAXTXPOWER=460;

- Check site Up or not with script: DSP UCELL:DSPT=BYNODEB,NODEBNAME="x";

3rd Action: Modify DL CAC parameters set to higher value. Parameters involved : DLCONVAMRTHD, DLCONVNONAMRTHD, DLOTHERTHD, DLHOTHD, DLCELLTOTALTHD

3. CE Blocking Optimization Step:

1st action: Verify CE license and CE board capability. Commands involved : DSP LICENSE, DSP BBPTC(Huawei LMT)

2nd Action: Physical Audit (involving TP analysis)

3rd Action: CE license and/or board upgrade

4th action: Modify LDR threshold. Sets involved : UCELLLDM, UCELLLDR

4. IUB Blocking Optimization Step:

1st Action: Verify Iub BW setting in Node-B and in RNC. Sets involved : IPPATH, IPLOGICPORT

2nd Action: Physical Audit (involving TP analysis)

3rd Action: Iub BW upgrade

4th action: Modify FTI to reduce Active Factor. Sets involved : TRMFACTOR, ADJMAP, ADJNODE

- Make Sure no Hardware Issue:

Hardware issue or wrong installation can be impacted to low CSSR such as WRFU problem or bad connector installation. You have to make sure no such hardware problem to make your CSSR good.

- Make Sure no Overshooting Coverage

As stated on resources optimization, you need to make sure no overshooting or coverage overlap to make your CSSR is good and no handle unnecessary traffic and make nodeB handle traffic heavily.

- Activate EFD(Enhanced Fast Dormancy) Feature

When fast dormancy, enhanced fast dormancy, or standard fast dormancy is applied, the UE can request the RNC to release the PS signaling connection if no more PS data is being transmitted. Upon receiving such a request, the RNC can either release the signaling connection and put the UE into idle mode, or maintain the signaling connection and put the UE through Cell_FACH to CELL/URA_PCH state to reduce battery consumption. The descriptions about fast dormancy, enhanced fast dormancy, and standard fast dormancy are as follows:

- With fast dormancy, after receiving a Signaling Connection Release Indication (SCRI) message from a UE, the RNC releases the UE RRC connection regardless of whether the message contains the cause value "UE Requested PS Data session end."

- With enhanced fast dormancy, UEs send SCRI messages that do not contain the cause value "UE

Requested PS Data session end" to the RNC. After receiving such an SCRI message, the RNC moves

the UE through Cell_FACH to CELL/URA_PCH state.

- Standard fast dormancy is applicable to fast dormancy UEs that comply with 3GPP Release 8 (R8 for short). With standard fast dormancy, UEs send SCRI messages that contain the cause value "UE

Requested PS Data session end" to the RNC. After receiving such an SCRI message, the RNC moves

the UE through Cell_FACH to CELL/URA_PCH state. Standard fast dormancy is valid only when theRNC has enabled the timer T323 in system information block type 1 (SIB1). You can refer to the document on your vendor to activate EFD feature.

- Adjust CPICH Power Setting

You can adjust CPICH Power setting to reduce coverage and improve your CSSR Ex: Change PCPICHPOWER from 330 to 300.

- Adjust Parameter QQUQALMIN

You can adjust QQUALMIN to improve CSSR and avoid congestion on blocking resources especially during event with potential to increasing traffic. Example: Change Qqualmin from -18 to -15 to avoid congestion.

You might also Need to know:
- How to Optimize Handover Success Rate in GSM Network
- CSSR Optimization for GSM
- Drop Call Rate Optimization in GSM and UMTS
- Power Control activation for Electricity Saving in Huawei GSM

CSSR Optimization for GSM and WCDMA

CSSR stands for Call Set up Success Rate  that is one of important KPI(Key Performances Indicator) in Optimization both GSM and UMTS/WCDMA. For the beginning we have to know that KPI in WCDMA including CSSR are separated based on each Services such as : CSSR CS( for Voice services), CSSR PS(for PS/Data Services), CSSR Video(for Video Services),CSSR HSDPA(For HSDPA Services), CSSR HSUPA(for HSUPA Services). In GSM there is only one type CSSR(Voice Services), For Data services usually called as PDASR(Packet data Access Success Rate) or TBF Establishment Success Rate.There are some tips how to optimizes CSSR in GSM and WCDMA.
1. GSM CSSR Optimization tips 
-Make Sure no Hardware issue
Hardware checking is always the first step to check all KPI because you will have no impact about your action if common problem like Hardware or Installation has occurred in your network. Defect GRFU/CU(TRX Module) or Combiner will make CSSR degraded below 95%. Swap module to other sector to identify the problem and replace bad module.Also make sure no problem with Power or Transmission. Check for TCH availability and active alarm to make sure no hardware issue.
-Make Sure no SD Blocking
Lack of SDCCH can make degradation in CSSR because SD Blocking included in CSSR Formula, make sure no SD Blocking found in your cells. If found then you have to add SD channel based on Erlang Calculation. If you lazy to calculate, just add 1 channel first :D ,then increase 1 channel again if still found Blocking on SDCCH.
-Make Sure no Frequency Interference
Frequency Interference can make high SD drop in your cells.SD drop also included in CSSR Formula,check for SD drop first if found then you need to clear the cells by re-tune/change BCCH Frequency. Interference problem also will impact to other KPI like drop call rate, Handover, etc
-Make Sure no Overshooting
Overshooting also will make your CSSR getting low and under threshold because to much attempt at the edge of Coverage with low RX Level. You have to make sure no overshooting occurred to make good CSSR. If found then you need to adjust your coverage by add Tilting value(Down Tilt)
-Tuning Parameter
You need to change parameter smoothly if all main problem have cleared. Try to change wisely related access parameter such as : RXLEVAMI/RXLEVACCMIN/AccMin(Different name between Vendor),RACHBT,T200,MAXRETR,etc.Make sure no extreme setting to avoid bad user perception :D.
-TRX Layering
Shifting traffic from bad TRX  to Good TRX can improve your KPI included CSSR. Try to set Good TRX as high priority  and bad TRX as lowest priority to improve your CSSR. TRX BCCH usually has better Quality to set as highest priority because Full Power(No Power Control).

2. WCDMA CSSR Optimization Tips
Continued here

You might also Need to know:
- How to Optimize Handover Success Rate in GSM Network
- Drop Call Rate Optimization in GSM and UMTS
- Power Control activation for Electricity Saving in Huawei GSM

Drop Call Rate Optimization, How to identify and finding root cause for Optimization solution on GSM and UMTS Network

Drop call rate is Main KPI that very important in RF Optimization. Drop Call  indicate how connection between Handset and Network become discontinue and causing bad experiences on user experiences because the call is release suddenly. In this paper I will share everything I know related drop call rate both on GSM and UMTS Network. Based on my experience the root cause of Drop Call Rate can be listed as follow:
- Hardware Problem.
This problem is very critical related to all KPI including Drop Call rate. If the problem is coming from hardware, percentage of drop call rate would be very high(usually more than 1 %) and you have to replace bad module with good module. For example in GSM Network you have to check and make sure TRX module such as GRFU/CU or Combiner/Duamco working properly. To make sure the problem was coming from hardware or bad module, you can identify by trying Swap module first. For example: if the problem high drop call rate is occurred in sector-1, you can swap TRX Module sector-1 to sector-2 and Combiner from sector-1 to sector-3. If the problem move to other sector then indicate the problem is coming from that module. For example in the above case if the problem move to sector-2, so the problem is TRX Module(GRFU/CU) or if the problem move to sector-3 then the problem should be Combiner/Duamco. In UMTS Network also same, if the problem is coming from hardware then you have to identify what module the problem is. You can identify the problem by swap WRFU Module. If the problem high drop call happened in one site/NodeB, you can try swap GTMU(Transmission module). Beside defect module the problem can be occurred due to wrong or bad installation such as Semirigid connection, Cross feeder problem or etc(especially for new site)
- Frequency Interference. 
Frequency interference is include in problem that can impact to high drop call rate because the Noise(Interference Signal) is very high and affecting to Carrier( primary Signal) and also affect to bad vice quality. To overcome the problem in GSM network you have to re-tune/ change Frequency that suspected Interference especially on BCCH Frequency for RF Hoping cells. As we know in GSM there area 2 type of Frequency Interference that called Co-Channel Interference(Same Frequency) and Adjacent Interference( Difference 1 Frequency  channel). Sample for Co-channel Frequency : Frequency Cell A=  Cell B = 670 with close location of cell each other. Sample for Adjacent Interference : Frequency Cell A=670 and Cell B=671 or 669 and the position of cells is close each of other. The solution in GSM network for interference is retune or change Frequency for one of the cells to avoid interference. in UMTS network the frequency interference also can occurred and indicated by bad Ec/No(Quality).Different with GSM, to overcome Interference in UMTS network is commonly solved by Change Antenna Tilt or reduce CPICH Power to avoid Coverage overlap. The other solution to reduce Drop call rate in UMTS Network is by making fast IRAT handover to GSM Network. In Huawei implement by Changing Parameter IRAT Handover 2D/2F.
- Overshooting Cells
Overshooting cell can be the one that causing high drop call rate in the network.To overcome this issue you have to change tilt configuration of Antenna, for example change Mechanical Tilt  from 0 to 2. Overshoot is common problem for both GSM and UMTS that causing drop call due to bad RX level in the edge of Coverage or bad RSCP and Ec/No in UMTS Network. The solution is same for both GSM and UMTS that is change Antenna configuration tilt/Down tilt.
- Missing neighbor.
Missing neighbor also will causing High drop call rate in your network. You have to check and make sure relation of the cells is complete and  no missing neighbor. The solution is same for both GSM and UMTS, you have to make sure no missing neighbor to avoid high drop call rate.
- Wrong Parameter Configuration
Wrong parameter configuration will causing high drop call rate in your network. Make sure to check all parameter and configure accordingly.In GSM there is parameter related drop call rate KPI such as : RLT(Radio Link Timeout), You can set by increase RLT to reduce drop call but will affect to Customer Experiences because release call is too long even when radio environment is poor and conditionally should be released. The other solution to reduce drop call related parameter is by adjust HO Parameter to make fast handover to a good cells in surrounding closest cells such as adjust PBGT, RXLEVMIN to target Cells. Making fast HO to a good cells can be implemented on both GSM and UMTS Network. You have to find out parameter related Radio Link and HO parameter in your vendor you are working for because the Parameter name would be different but in same Idea That is Radio Link Time out and Handover Parameter.
- Power or Transmission Problem
Power problem can make high drop call rate in the network. You have to make sure no power problem by check the alarm and Cell Availability.If the problem occurred you need to follow up the problem to Field Maintenance Team to fix it.
Transmission problem also can make drop call rate very high and affecting to your KPI. You need to check alarm related transmission and make sure also cell availability is stable. If you found transmission problem the you have to follow up the problem to Transmission Team to check and fix it.
- Contour Problem(Hilly/Rural Contour)
Bad contour can be the one that causing high drop call rate especially if your network in Hilly or Rural area. Check and identify your cells by drive test to make sure the problem is causing by contour or check the coverage by Simulation. If the problem is bad contour then you have to  adjust tilt of the cell or re-azimuth make sure coverage continuous.
- Discontinuous Coverage
If your coverage discontinue due to lack of site then you need to propose new site to your operator. Discontinue coverage also can occurred due to wrong antenna configuration such as over tilt. You need to check tilt configuration of the antenna and make sure no over tilt that causing coverage become discontinue.

Thanks for visiting my blog and hope can help your network problem related Drop Call Rate Optimization on GSM and UMTS Network

You might also Need to know:
- How to Optimize Handover Success Rate in GSM Network
- CSSR Optimization for GSM and WCDMA
- Power Control activation for Electricity Saving in Huawei GSM
- Handover Optimization Improvement step in GSM