DT BLER KPI Cant Meet Target after Modifying BlerQualityKey WordsBlerQuality DLBLERKPI SymptomWe found DL BLER KPI cant meet targer when taking DT Acceptance at I country A project.Cause AnalysisOne region engineer found DL BLER cant meet target when they take DT acceptance,then take some actions to check probable resaons.First by parameter check we found TrchType value is TRCH_DCH,that is to say business subflow prefer to bear on transmission channel(DCH) .Meanwhile, BLERQuality value is -10(when TrchType value is TRCH_DCH, BLERQuality must be setting ),as shown in the belowing picture,

The paremeter BLERQuality shows what transmission quality target DCH channel should meet,it is the DCH BLER targer value at UU interference.It has the following influence on radio network: Network BLER will be higher if the paremeter value is big,at the contrary, Network BLER will be lower if the paremeter value is small. So we suspect because this parameter value is too high which lead to BLER increase,and the channel quality is worse accordingly.All of this can lead to DT BlER cant meet target.Handling ProcessChecking RAB Index is 40-78 when parameter BLERQuality value is -10,that is to say this paremeter value is -10 only for INTERACTIVE and BACKGROUNDBE service of BE service ,as shown in the following picture,

Subsequently we modified parameter BLERQuality from -10 to -20 for INTERACTIVE and BACKGROUNDBE service.To verify its impact on PS we monitor related counter and found thant it cant become worse after modify BLERQuality,as shown in the following picture,Drop HSUPA:

Drop HSDPA:

Drop PS:

Comparing DT BLER for different BLERQuality value and the result shown as the following picture,DT Result of BLERQuality=-10,

DT Result of BLERQuality=-20,

From the comparison we can see that DL BLER improved after modifying BLERQuality from -10 to -20 and it can meet the target.The script show as following:MOD UTYPRABOLPC:RABINDEX=40, SUBFLOWINDEX=0, TRCHTYPE=TRCH_DCH, DELAYCLASS=1, BLERQUALITY=-20;MOD UTYPRABOLPC:RABINDEX=41, SUBFLOWINDEX=0, TRCHTYPE=TRCH_DCH, DELAYCLASS=1, BLERQUALITY=-20;MOD UTYPRABOLPC:RABINDEX=42, SUBFLOWINDEX=0, TRCHTYPE=TRCH_DCH, DELAYCLASS=1, BLERQUALITY=-20;MOD UTYPRABOLPC:RABINDEX=43, SUBFLOWINDEX=0, TRCHTYPE=TRCH_DCH, DELAYCLASS=1, BLERQUALITY=-20;MOD UTYPRABOLPC:RABINDEX=44, SUBFLOWINDEX=0, TRCHTYPE=TRCH_DCH, DELAYCLASS=1, BLERQUALITY=-20;MOD UTYPRABOLPC:RABINDEX=45, SUBFLOWINDEX=0, TRCHTYPE=TRCH_DCH, DELAYCLASS=1, BLERQUALITY=-20;MOD UTYPRABOLPC:RABINDEX=46, SUBFLOWINDEX=0, TRCHTYPE=TRCH_DCH, DELAYCLASS=1, BLERQUALITY=-20;MOD UTYPRABOLPC:RABINDEX=47, SUBFLOWINDEX=0, TRCHTYPE=TRCH_DCH, DELAYCLASS=1, BLERQUALITY=-20;MOD UTYPRABOLPC:RABINDEX=48, SUBFLOWINDEX=0, TRCHTYPE=TRCH_DCH, DELAYCLASS=1, BLERQUALITY=-20;MOD UTYPRABOLPC:RABINDEX=70, SUBFLOWINDEX=0, TRCHTYPE=TRCH_DCH, DELAYCLASS=1, BLERQUALITY=-20;MOD UTYPRABOLPC:RABINDEX=71, SUBFLOWINDEX=0, TRCHTYPE=TRCH_DCH, DELAYCLASS=1, BLERQUALITY=-20;MOD UTYPRABOLPC:RABINDEX=72, SUBFLOWINDEX=0, TRCHTYPE=TRCH_DCH, DELAYCLASS=1, BLERQUALITY=-20;MOD UTYPRABOLPC:RABINDEX=73, SUBFLOWINDEX=0, TRCHTYPE=TRCH_DCH, DELAYCLASS=1, BLERQUALITY=-20;MOD UTYPRABOLPC:RABINDEX=74, SUBFLOWINDEX=0, TRCHTYPE=TRCH_DCH, DELAYCLASS=1, BLERQUALITY=-20;MOD UTYPRABOLPC:RABINDEX=75, SUBFLOWINDEX=0, TRCHTYPE=TRCH_DCH, DELAYCLASS=1, BLERQUALITY=-20;MOD UTYPRABOLPC:RABINDEX=76, SUBFLOWINDEX=0, TRCHTYPE=TRCH_DCH, DELAYCLASS=1, BLERQUALITY=-20;MOD UTYPRABOLPC:RABINDEX=77, SUBFLOWINDEX=0, TRCHTYPE=TRCH_DCH, DELAYCLASS=1, BLERQUALITY=-20;MOD UTYPRABOLPC:RABINDEX=78, SUBFLOWINDEX=0, TRCHTYPE=TRCH_DCH, DELAYCLASS=1, BLERQUALITY=-20;Suggestions and Summary No

2013-5-22,6, 6