cdma正常信令及异常信令分析呼叫处理流程及网络优化.ppt

呼叫处理流程及网络优化

内容第一局部–呼叫流程第二局部–常规掉话、接入失败及掉话分析。

cdma呼叫过程第一局部

CDMA呼叫处理AcquisitionoftheCDMASystemIdleModeHandoffRegistrationTerminationOriginationEndofaCallHandoff

是怎么工作的?ReceiverRFSectionIF,DetectorTransmitterRFSectionVocoderDigitalRakeReceiverTrafficCorrelatorPNxxxWalshxxSTrafficCorrelatorPNxxxWalshxxTrafficCorrelatorPNxxxWalshxxPilotSearcherPNxxxWalsh0DecoderCPUDuplexerTransmitterDigitalSectionLongCodeGen.OpenLoopTransmitGainAdjustMessagesMessagesAudioAudioPacketsSymbolsSymbolsChipsRFRFAGC

AcquisitionoftheCDMASystemCDMA呼叫过程

找到一个频率Mobilescansforwardlinkfrequencies:(CellularorPCS,dependingonmodel)HistoryListPreferredRoamingListuntilaCDMAsignalisfound.NOCDMA?!GotoAMPS,ortoapower-savingstandbymodeHISTORYLISTLast-used:Freq/SIDxFreq/SIDyFreq/SIDzFreq/SIDtFreq/SIDuetc.FREQUENCYLISTS:PREFERREDROAMINGLISTFreq/SID1Freq/SID2Freq/SID3Freq/SID4Freq/SID5etc.ForwardLinkFrequencies(BaseStationTransmit)ADBEFCunlic.dataunlic.voiceADBEFC1850MHz.1910MHz.1990MHz.1930MHz.1900MHz.PCSSpectrum824MHz.835845870880894869849846.5825890891.5Paging,ESMR,etc.ABAB800MHz.CellularSpectrumReverseLinkFrequencies(MobileTransmit)

发现最强的导频信号,读取同步信道信息RakeFingers???ReferencePNActivePilotEc/Io0032K512ChipsPN1.PilotSearcher扫描全部PNAllPNOffsets0-2098/05/2423:14:09.817[SCH]SyncChannelMessageMSG_LENGTH=208bitsMSG_TYPE=SyncChannelMessageP_REV=3MIN_P_REV=2SID=179NID=0PILOT_PN=168OffsetIndexLC_STATE=0x0348D60E013SYS_TIME=98/05/2423:14:10.160LP_SEC=12LTM_OFF=-300minutesDAYLT=0PRAT=9600bpsRESERVED=12.解码Walsh32,读取同步信息。SYNCCHANNELMESSAGEHandsetRakeReceiverRF?x?LOSrchPN???W0F1PN168W32F2PN168W32F3PN168W32

配置信息读完同步信息后，开始读寻呼信道消息，并开始不停监测该信道。在通话前，必须收集到完整的配置信息。配置信息每1.28seconds会重复。有新的消息会更新，如没有600S也会更新一次

到寻呼信道获得配置信息RakeFingers???ReferencePNActivePilotEc/Io0032K512ChipsPNAllPNOffsets0-20KeepRakefinger(s)onstrongestavailablePN,decodeWalsh