Network Analysis

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Network Analysis

• BOB

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Service Observation
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Signal trace
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CNT
5

• Call/Paging setup
• Drop call
• Handoff

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Call/Paging setup

• Call setup

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• Paging call

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Call setup failure reason

• SDM_Activate_Fail_AcquirePreambleFail_Normal(?????
  ,???????,????preamble,????,??se,ve???)
• ERR_SPS_RLSA_DSPM_CLH_TimerExpired_Twaitorder(????
  ?,FCH??)
• ERR_SPS_RLSA_BSSAP_TE_Tassignment

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SDM_Activate_Fail_AcquirePreambleFail_Normal
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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.

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SDM_Activate_Fail_AcquirePreambleFail_Norma

• Solution
• 1.Check RC ,PN-offset
• 2. CE resouse
• 3. Drive test (Ec/Io)

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SDM_Activate_Fail_AcquirePreambleFail_Normal
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2. ERR_SPS_RLSA_DSPM_CLH_TimerExpired_Twaitorder
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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

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2. ERR_SPS_RLSA_DSPM_CLH_TimerExpired_Twaitorder
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3.ERR_SPS_RLSA_BSSAP_TE_Tassignment

• BSSAP send EV_S_AvfServiceAssignment message to
  DSMP,but within 7s ,EV_S_AvrAssignmentComplete
  doesnt be send and EV_S_AvrAssignmentFailure is
  received.

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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

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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

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Voice Release
MS
Normal release num
Traffice time finish
MSC
Normal release num
Traffice time finish
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• SDM_Link_Fail_RevTooManyBadFrm

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1. signal weak
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• 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.

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• 2. MS and BSS PN-offset is not consistent

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Handoff failure

• ERR_SPS_RLSA_DSPM_HOH_TimerExpired_Thocompletion
• ERR_SPS_RLSA_DSPM_HOH_TimerExpired_Thoreq

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ERR_SPS_RLSA_DSPM_HOH_TimerExpired_Thocompletion

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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.

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Solution

• Check DSMP timer (5s default)

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• 2. check BTS RFE-TX

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ERR_SPS_RLSA_DSPM_HOH_TimerExpired_Thoreq
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• 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)