3G網(wǎng)絡(luò)呼叫時(shí)延較長(zhǎng)問(wèn)題分析

3G呼叫時(shí)延長(zhǎng)問(wèn)題分析報(bào)告在3G網(wǎng)絡(luò)優(yōu)化過(guò)程中發(fā)現(xiàn)，VC和VP的呼叫接續(xù)時(shí)延較長(zhǎng)，一般都接近5秒左右，嚴(yán)重影響了用戶(hù)感受。對(duì)此問(wèn)題可以進(jìn)行信令的跟蹤，根據(jù)主被叫的呼叫信令流程進(jìn)行分析，我們可以采用對(duì)比法完成，。例如：小區(qū)A和小區(qū)B都采用同樣的呼叫測(cè)試方法，使用3G測(cè)試號(hào)碼互撥。測(cè)試地點(diǎn)無(wú)線(xiàn)環(huán)境良好。小區(qū)A信令分析結(jié)果：下表是小區(qū)A的主被叫手機(jī)呼叫的信令流程，本次呼叫耗時(shí)4.11秒。UE序號(hào)時(shí)間消息方向消息類(lèi)型標(biāo)準(zhǔn)呼叫流程時(shí)延差別UE1254618:17:32(50)From-UERRC_RRC_CONNECT_REQRRCCONNREQUE1256118:17:32(50)From-CNRANAP_COMMON_IDCOMMON_ID0.24

UE1256618:17:32(50)From-CN RANAPSECURITYMODECOMMANDUE1257818:17:32(51)To-UERRC_SECURITY_MODE_CMDUE1259318:17:32(63)From-UERRC_SECURITY_MODE_CMPUE1260118:17:32(63)To-CNRANAP_SECURITY_MODE_COMPLETEUE1262418:17:32(74)To-CNRANAPDIRECTTRANSFERSetupUE1263918:17:32(77)From-CNRANAPDIRECTTRANSFERcallproceedingUE2139118:17:32(91)From-CNRANAP_PAGINGPAGINGUE2139218:17:34(69)From-UERRC_RRC_CONNECT_REQRRCCONNREQUE2140718:17:34(69)From-CNRANAP_COMMON_IDCOMMON_ID0.27UE2141218:17:34(69)From-CNRANAP_SECURITY_MODE_COMMANDUE2142418:17:34(70)To-UERRC_SECURITY_MODE_CMDUE2143918:17:34(83)From-UERRC_SECURITY_MODE_CMPUE2144718:17:34(83)To-CNRANAP_SECURITY_MODE_COMPLETEUE2144918:17:34(83)Out-of-RNCDT1_MSGUE2145518:17:34(84)In-RNCDT1_MSGUE2145718:17:34(84)From-CNRANAP_DIRECT_TRANSFERUE2145818:17:34(84)To-UERRC_DL_DIRECT_TRANSFUE2146918:17:34(95)From-UERRC_UL_DIR_TRANSFUE2147018:17:34(95)To-CNRANAP_DIRECT_TRANSFERUE2147218:17:34(95)Out-of-RNCDT1_MSGUE2147518:17:34(96)In-RNCDT1_MSGUE2147718:17:34(96)From-CNRANAP_DIRECT_TRANSFERSetUpUE2147818:17:34(96)To-UERRC_DL_DIRECT_TRANSFUE2149118:17:35(09)From-UERRC_UL_DIR_TRANSFUE2149218:17:35(09)To-CNRANAP_DIRECT_TRANSFERcallconfirmUE1299618:17:35(13)From-CNRANAP_RAB_ASSIGNMENT_REQRABASSREQ0.74UE1300718:17:35(23)From-UERRC_ACTIVE_SET_UPDATE_CMPUE1300818:17:35(23)From-UERRC_ACTIVE_SET_UPDATE_CMPUE1300918:17:35(23)From-UERRCACTIVESETUPDATECMPUE1307118:17:35(23)To-CNQAAL2ESTABLISHREQUESTUE1307518:17:35(24)From-CNQAAL2ESTABLISHCONFIRMUE1313518:17:35(24)To-NodeBQAAL2_MODIFY_REQUESTUE1314218:17:35(25)From-NodeBQAAL2_MODIFY_ACKNOWLEDGEUE1315518:17:35(25)To-NodeBNBAPRLRECFGPREPUE1315618:17:35(28)From-NodeBNBAP_RL_RECFG_READYUE1316918:17:35(28)To-NodeBQAAL2_ESTABLISH_REQUESTUE1317318:17:35(30)From-NodeBQAAL2_ESTABLISH_CONFIRMUE1318918:17:35(30)To-UERRCRBSETUPUE1319018:17:35(30)To-UERRCRBSETUPUE1319118:17:35(30)To-UERRCRBSETUPUE1322818:17:35(51)To-NodeBNBAP_RL_RECFG_COMMITUE1UE1UE1UE1UE1UE1UE2UE2UE2UE2UE2UE2UE2UE2UE2UE2UE2UE2UE2UE2UE2UE2UE13256326632673268329133061497149915431547159916061619162016331637165316881719173017361749344818:17:35(83)18:17:35(87)18:17:35(87)18:17:35(87)18:17:35(87)18:17:35(87)18:17:35(90)18:17:35(91)18:17:35(91)18:17:35(91)18:17:35(92)18:17:35(93)18:17:35(93)18:17:35(95)18:17:35(95)18:17:35(97)18:17:35(97)18:17:36(18)18:17:36(56)18:17:36(56)18:17:36(56)18:17:36(56)18:17:36(61)To-NodeBFrom-UEFrom-UEFrom-UETo-UETo-CNIn-RNCFrom-CNTo-CNFrom-CNTo-NodeBFrom-NodeBTo-NodeBFrom-NodeBTo-NodeBFrom-NodeBTo-UETo-NodeBFrom-UETo-UETo-UETo-CNFrom-CNNBAPDLPWRCTRLREQRRCRBSETUPCMPRRCRBSETUPCMPRRCRBSETUPCMPRRCMEASCTRLRANAPRABASSIGNMENTRESPDT1MSGRANAPRABASSIGNMENTREQQAAL2ESTABLISHREQUESTQAAL2ESTABLISHCONFIRMQAAL2MODIFYREQUESTQAAL2_MODIFY_ACKNOWLEDGENBAPRLRECFGPREPNBAP_RL_RECFG_READYQAAL2ESTABLISHREQUESTQAAL2_ESTABLISH_CONFIRMRRCRBSETUPNBAPRLRECFGCOMMITRRCRBSETUPCMPRRCMEASCTRLRRCMEASCTRLRANAPRABASSIGNMENTRESPRANAPDIRECTTRANSFERRABASSRESPRABASSREQRABASSRESPAlerting0.65分析：上表是小區(qū)A一次完整的主被叫呼叫的流程，通過(guò)和小區(qū)B的呼叫流程對(duì)比，我們找到了小區(qū)A呼叫時(shí)延過(guò)長(zhǎng)的幾個(gè)部分。第一部分：就是上表中“時(shí)延差別”列里面的紅色格子，該格子里面是呼叫流程中的鑒權(quán)加密流程，該流程耗時(shí)約0.24秒左右，對(duì)比小區(qū)8的呼叫流程發(fā)現(xiàn)，小區(qū)B的呼叫流程中沒(méi)有加入鑒權(quán)加密流程，因此這一部分呼叫時(shí)延小區(qū)\比小區(qū)B多出來(lái)0.5秒（主叫時(shí)延加被叫時(shí)延）。第二部分：差別在呼叫流程中的RAB建立流程上。上表中“時(shí)延差別”列里面的綠色格子即RAB的建立流程。對(duì)比小區(qū)B和小區(qū)A，大家的RAB建立時(shí)長(zhǎng)大約都是0.7秒左右，差別不大。但問(wèn)題出在CN向被叫手機(jī)發(fā)起RAB建立流程的時(shí)間上。從上表看出小區(qū)A是在主叫手機(jī)RAB流程完全建立，向系統(tǒng)發(fā)送RAB_ASSIGNMENT_RESP以后，系統(tǒng)才向被叫手機(jī)發(fā)送RAB_ASSIGNMENT_REQ開(kāi)始被叫的RAB建立流程。而小

區(qū)B則是系統(tǒng)同時(shí)向主被叫發(fā)起RAB建立請(qǐng)求，主被叫同時(shí)進(jìn)行RAB建立流程。這么一算小區(qū)A的呼叫時(shí)延在這一部分比小區(qū)B多出來(lái)0.7秒左右。以上兩個(gè)部分造成小區(qū)A呼叫時(shí)延比小區(qū)B多出來(lái)1.2秒左右。下表是小區(qū)B的主被叫呼叫流程，本次呼叫耗時(shí)2.58秒：UE序號(hào)時(shí)間消息方向消息類(lèi)型標(biāo)準(zhǔn)呼叫流程時(shí)延差別UE1117:51:40(91)From-UERRC_RRC_CONNECT_REQUE11617:51:40(91)From-CNRANAP_COMMON_IDCOMMON_IDUE12417:51:40(97)To-CNRANAPDIRECTTRANSFERSetUpUE13017:51:41(02)From-CNRANAP_DIRECT_TRANSFERCallProceedingUE13117:51:41(02)To-UERRC_DL_DIRECT_TRANSFUE13717:51:42(74)In-RNCDT1_MSGUE13917:51:42(74)From-CNRANAP_RAB_ASSIGNMENT_REQRABASSREQUE125317:51:43(41)To-CNRANAP_RAB_ASSIGNMENT_RESPRABASSRESPUE125617:51:43(41)Out-of-RNCDT1_MSGUE125917:51:43(49)In-RNCDT1_MSGUE126117:51:43(49)From-CNRANAPDIRECTTRANSFERAlertingUE2117:51:39(87)From-CNRANAP_PAGINGUE2217:51:42(43)From-UERRCRRCCONNECTREQUE21717:51:42(43)From-CNRANAPCOMMONIDCOMMONIDUE22017:51:42(43)In-RNCDT1_MSGUE22217:51:42(43)From-CNRANAPDIRECTTRANSFERSetUpUE23617:51:42(57)To-CNRANAP_DIRECT_TRANSFERCallconfrimUE23817:51:42(57)Out-of-RNCDT1_MSGUE24017:51:42(70)In-RNCDT1MSGUE24217:51:42(70)From-CNRANAPRABASSIGNMENTREQRABASSREQUE227117:51:43(37)To-CNRANAP_RAB_ASSIGNMENT_RESPRABASSRESP根據(jù)小區(qū)B的主被叫