下行速率异常问题定位

1、问题描述：现网出现MCS阶数较低的异常问题，时频域均满调度，空口环境良好，但MCS阶数始 终在01阶导致速率较低（编码方式为QPSK），速率一般在4MbpsEratni*he?ppd*日孔孔二.日*律曲# a,j 31 - *-心5Wa*i PVSCHFWIaM此切卜州歆“DL*DL*EDL*Dt七 t-TnlLTfWDS*f kniiir Am*七 krilW*；心*收y ir数据分析：从基站信令跟踪来看，前期反馈LOG默认承载建立为QCI=6，有问题的终端默认承载建 立为QCI=5。协议23203已经做了规定，QCI=5的业务用于IMS信令传输Table 6.1.7: Standardiz

2、ed QCI characteristicsQCIReso urce TypePrior ityPac ket Delay Budget (NOTE 1)Pack et Error LossRate (NOTE 2)Example Services1(NOTE 3)GBR2100ms10-2Conversational Voice2(NOTE 3)4150ms10-3Conversational Video (Live Streaming)3(NOTE 3)350 m s10-3Real Time Gaming4(NOTE 3)5300ms10-6Non-Conversational Vide

3、o(Buffered Streaming)5 (NOTE 3)Non-GBR1100ms10-6IMS Signalling6 (NOTE 4)6300 ms10-6Video (Buffered Streaming) TCP-based (e.g., www, e-mail, chat, ftp, p2p file sharing, progressive video, etc.)7(NOTE 3)7100 ms10-3Voice,Video (Live Streaming) Interactive Gaming8 (NOTE 5)8300 ms10-6Video (Buffered Str

4、eaming) TCP-based (e.g., www, e-mail, chat, ftp, p2p filesharing, progressive video, etc.)9 (NOTE 6)9基站侧为了保证信令的正确解调，做了特殊处理：下行QCI5调度降阶处理，使用MCS 0阶或者1阶，所以下行流量会被限制。前台速率低时测试现象和实现相符：DLSCECKleOirtMCS IndexOLTOCMriCoirtDLPCeCodelCMTqp睛网1MMPCCCodeO SCC CexleO PCC Cdel SCCCodel PCC Tolal SCC TotalDLPCCCMeIRKA

5、rtDL5CCCodelRKArtMCS16 P 18 均T21 -222324 25 26 N S8 29 iO JI TDLggmurt aOOODGODdD DOOO0L蹴敞gut1、新卡如果开户设置为QCI=5，立即出现问题；2、老卡：如果不重新开关机（达到MME清除上下文信息的周期），之前上下文不释放，依然为QCI=6,；终端开关机后（达到MME清除上下文信息的周期），上下行重新建 立到QCI=5，就会出现该问题。处理方法：核心网将默认承载建立中的QCI修改为6,验证测试正常，速率恢复:HUAVE4W12RSRPidDmi RRqranj 监ETOPII13RS Fl F阳：-74 EBRSFEiHg；-疑闵州时 puscupgyao PUCCh PmnSrO FAEH5HS FcFl&t用匚 RaMrHfrif Me HflrtwiMBl PDCCHUL&iml Ccurrt硕PDCCH DL&art Ccxn财心排 SIHFdBCi19Tranmim Ha da1M3Mi.1 9FJHB|FW2SJWH1(da3B隘应洲R近商电网归皿时F2rii4 3NHl(diF 口TfPCCCEKkO5CC EodvC-PC 匚 dlVLC. EodalPOC TdkilSOCTal PKftl(111BQM 仲o ITD17QllOAM EjOL rQ