MTK平臺的srvcc相關故障

1、在主叫未收到振鈴消息前發生srvcc

UE在LTE下發起VOLTE電話，因爲4G信號差，在響鈴以前觸發了SRVCC，懷疑該網絡不support bsrvcc（響鈴以前SRVCC），致使SRVCC失敗，進一步致使Call自動掛斷。

395304 01-18 11:59:21.108425 7448 7469 I VoLTE_Auto_Testing: [0][acct] event/recv/srvcc/start

395305 01-18 11:59:21.108516 7448 7469 I VoLTE UA: call_session_release_session_not_transferred_in_srvcc: release the session, call_id=[1] (vendor/mediatek/proprietary/frameworks/opt/volte/volte_ua/src/call/call.c:863)
395306 01-18 11:59:21.111770 7448 7469 I VoLTE_Auto_Testing: [0][call] msg/send/0/1/resp/480/request_id=596902168/conn_id=131073
395331 01-18 11:59:21.114558 7448 7469 I VoLTE UA: SRVCC: call [1] send 480_TEMP_UNAVAILABLE, res=[0] (vendor/mediatek/proprietary/frameworks/opt/volte/volte_ua/src/call/call.c:875)
395336 01-18 11:59:21.115375 7448 7469 I VoLTE_Auto_Testing: [0][call] event/send/0/1/ecpi/133/0/0/3/mode/0/cause/21/q850/0/pau/
395379 01-18 11:59:21.118427 7448 7469 I VoLTE_Auto_Testing: [0][call] event/srvcc_call_ctxt_transfer/0

一、從log看網絡已經成功切換了，以後發了[IMSP_AT_I s23]AT+ESRVCCTFR=0
->0表明0通call從IMS切換到CS失敗

This command is used for transferring IMS call table to CS domain.
After transfer successfully, modem will report Unsolicited Result Code +ESRVCCTFR: <call_no>[,<call1_id>[,<call2_id>[,…]]]
If transfer fails, modem will report Unsolicited Result Code +ESRVCCTFR: 0
+ESRVCCTFR=<call_no>[,<call1_id>,<call1_mode>,<call1_direction>,<call1_state>,<call1_ecc_category>,<call1_number_format>,<call1_number>[,<call2_id>,<call2_mode>,<call2_direction>,<call2_state>,<call2_ecc_category>,<call2_number_format>,<call2_number> [,…]]]
<call_no>: 1~7 interger type. Number of calls to be transferred

67249669, 11:59:20:666 2017/01/18, MOD_ERRC_MOB, , TRACE_PEER, [MS->NW] ERRC_MeasurementReport[13] eventB2 GSM ncell[60/0] rslt[-363][0] pcell[38950/28] rslt[-466][-30]
275966, 0, 67256774, 11:59:21:266 2017/01/18, MOD_ERRC_CONN, , TRACE_PEER, [NW->MS] ERRC_MobilityFromEUTRACommand(CSFB:[0],purpose:[MobilityFromEUTRACommand_r8_IEs_purpose_handover_selected],targetRAT:[Handover_targetRAT_Type_geran])
277501, 0, 67258573, 11:59:21:266 2017/01/18, MOD_RRM_TDD, , TRACE_PEER, [MS->NW] RR_HANDOVER_COMPLETE //srvcc切換到2G

二、從哪裏check到srvcc失敗？？
->從上面AT++ESRVCCTFR=0或者如下log均可以看出SRVCC失敗（前面貴司貼的MD log只是接入網部分的成功，但並非完整的SRVCC的切換，SRVCC還得考慮IMS域和CS域的call session transfer是否成功）
395305 01-18 11:59:21.108516 7448 7469 I VoLTE UA: call_session_release_session_not_transferred_in_srvcc: release the session, call_id=[1] (vendor/mediatek/proprietary/frameworks/opt/volte/volte_ua/src/call/call.c:863)
395306 01-18 11:59:21.111770 7448 7469 I VoLTE_Auto_Testing: [0][call] msg/send/0/1/resp/480/request_id=596902168/conn_id=131073
395331 01-18 11:59:21.114558 7448 7469 I VoLTE UA: SRVCC: call [1] send 480_TEMP_UNAVAILABLE, res=[0] (vendor/mediatek/proprietary/frameworks/opt/volte/volte_ua/src/call/call.c:875)
395336 01-18 11:59:21.115375 7448 7469 I VoLTE_Auto_Testing: [0][call] event/send/0/1/ecpi/133/0/0/3/mode/0/cause/21/q850/0/pau/
395379 01-18 11:59:21.118427 7448 7469 I VoLTE_Auto_Testing: [0][call] event/srvcc_call_ctxt_transfer/0

->終端不用上報SRVCC成功給網絡，SRVCC是網絡控制的。貴司可參考23.216先學習

☆通常來講若是網絡支持bSRVCC會在網絡給的invite或者183中的feature-caps中帶有pre-alerting，請問您是在哪裏進行的測試？目前來講中國移動的bSRVCC驗證測試主要是春節後在杭州長沙兩地進行。對比機測試是請您使用其餘平臺的手機，用相同的卡作振鈴前的SRVCC測試,感謝您的配合。