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Network Analysis. BOB. Service Observation. Signal trace. CNT. Call/Paging setup Drop call Handoff. Call/Paging setup. Call setup. Paging call. Call setup failure reason. SDM_Activate_Fail_AcquirePreambleFail_Normal( 第一次握手，在定时器超时前，没有捕获 preamble ，若能捕获，分配 se,ve 等资源 )
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Network Analysis BOB
Call/Paging setup • Drop call • Handoff
Call/Paging setup • Call setup
Call setup failure reason • SDM_Activate_Fail_AcquirePreambleFail_Normal(第一次握手，在定时器超时前，没有捕获preamble，若能捕获，分配se,ve等资源) • ERR_SPS_RLSA_DSPM_CLH_TimerExpired_Twaitorder（第二次握手，FCH配置） • ERR_SPS_RLSA_BSSAP_TE_Tassignment
SDM_Activate_Fail_AcquirePreambleFail_Normal • BTS receives terminal origination and then arranges the necessary resource for traffic. • When procedure goes to acquire reverse preamble with 5s, it is failed because of bad air link.
SDM_Activate_Fail_AcquirePreambleFail_Norma Solution 1.Check RC ,PN-offset 2. CE resouse 3. Drive test (Ec/Io)
2. ERR_SPS_RLSA_DSPM_CLH_TimerExpired_Twaitorder • Bad wireless envirement,lose the reverse ack order message; • Under opening “frame check”，BTS and BSC timer is different • Transmitte code ratio
3.ERR_SPS_RLSA_BSSAP_TE_Tassignment • BSSAP send EV_S_AvfServiceAssignment message to DSMP,but within 7s ,EV_S_AvrAssignmentComplete doesn’t be send and EV_S_AvrAssignmentFailure is received.
3.ERR_SPS_RLSA_BSSAP_TE_Tassignment Reason and solution: • Timere is short ,check timer,the default value is 6s. • DSMP instance configuration is large • DSMP CPU overload
Dropped CallsFailure Mobile : • 1) continue 12 bad frame/5s timer for FER • 2) within 8s,not receive ack order from BTS BTS: 1)Continue 12 bad frame from reverse 2) not receive ack order from BTS
Voice Release MS Normal release num Traffice time finish MSC Normal release num Traffice time finish
Terminal sends PSMM to BTS because of weak signal. • BTS then sends Handoff Direction Message but receives no MSACK from BTS. • After sending PMRO for 4 times and wait 18 for no response. • By Judging the reverse air link was broken down, BSSAP starts release procedure to release resources on BSS and MSS sides.
Handoff failure • ERR_SPS_RLSA_DSPM_HOH_TimerExpired_Thocompletion • ERR_SPS_RLSA_DSPM_HOH_TimerExpired_Thoreq
ERR_SPS_RLSA_DSPM_HOH_TimerExpired_Thocompletion • Terminal is under weak coverage. • It sends PSMM to BTS but long time receives no BSACK. At the same time, after receiving PSMM, BTS sends Handoff Direction Message to terminal to instruct soft handoff. • However, BSS receives no Handoff Completion Message from terminal side. The communication between BSS and MS has been kept silent for over 5 seconds. Then HO failure generates. This type of HO failure is usually caused by fragile air link.
Solution • Check DSMP timer (5s default)
Solution: • 1.check DSMP Timer setting(default 5s） • 2.check Abis link • 3.check target BTS card status ,CHM (CE status, whether there are blocking CEs)