Section: 5.5.1.2.5A Attach for emergency bearer services not accepted by the network
Content: If the attach request for emergency bearer services cannot be accepted by the network, the MME shall send an ATTACH REJECT message to the UE including EMM cause #5 "IMEI not accepted" or one of the EMM cause values as described in clause 5.5.1.2.5. NOTE 1: If EMM cause #11 is sent to a UE of a roaming subscriber attaching for emergency bearer services and the UE is in automatic network selection mode, it cannot obtain normal service provided by this PLMN. Upon receiving the ATTACH REJECT message including EMM cause #5, the UE shall enter the state EMM-DEREGISTERED.NO-IMSI. Upon receiving the ATTACH REJECT message including one of the other EMM cause values, the UE shall perform the actions as described in clause 5.5.1.2.5 with the following addition: the UE shall inform the upper layers of the failure of the procedure. NOTE 2: This can result in the upper layers requesting establishment of a CS emergency call (if not already attempted in the CS domain), or other implementation specific mechanisms, e.g. procedures specified in 3GPP TS 24.229[ IP multimedia call control protocol based on Session Initiation Protocol (SIP) and Session Description Protocol (SDP); Stage 3 ]  [13D] can result in the emergency call being attempted to another IP-CAN. If the attach request for emergency bearer services fails due to abnormal case a) in clause .2.6, the UE shall perform the actions as described in clause 5.5.1.2.6 and inform the upper layers of the failure to access the network. NOTE 3: This can result in the upper layers requesting establishment of a CS emergency call (if not already attempted in the CS domain), or other implementation specific mechanisms, e.g. procedures specified in 3GPP TS 24.229[ IP multimedia call control protocol based on Session Initiation Protocol (SIP) and Session Description Protocol (SDP); Stage 3 ]  [13D] can result in the emergency call being attempted to another IP-CAN. If the attach request for emergency bearer services fails due to abnormal cases b), c) or d) in clause .2.6, the UE shall perform the actions as described in clause 5.5.1.2.6 with the following addition: the UE shall inform the upper layers of the failure of the procedure. NOTE 4: This can result in the upper layers requesting establishment of a CS emergency call (if not already attempted in the CS domain), or other implementation specific mechanisms, e.g. procedures specified in 3GPP TS 24.229[ IP multimedia call control protocol based on Session Initiation Protocol (SIP) and Session Description Protocol (SDP); Stage 3 ]  [13D] can result in the emergency call being attempted to another IP-CAN. In a shared network, upon receiving the ATTACH REJECT message, the UE shall perform the actions as described in clause 5.5.1.2.5, and shall: a) inform the upper layers of the failure of the procedure; or NOTE 5: This can result in the upper layers requesting establishment of a CS emergency call (if not already attempted in the CS domain), or other implementation specific mechanisms, e.g. procedures specified in 3GPP TS 24.229[ IP multimedia call control protocol based on Session Initiation Protocol (SIP) and Session Description Protocol (SDP); Stage 3 ]  [13D] can result in the emergency call being attempted to another IP-CAN . b) attempt to perform a PLMN selection in the shared network and, if an attach for emergency bearer services was not already attempted with the selected PLMN and the ATTACH REQUEST message: - did not include a PDN CONNECTIVITY REQUEST message with request type set to "handover of emergency bearer services", initiate an attach for emergency bearer services to the selected PLMN; or - did include a PDN CONNECTIVITY REQUEST message with request type set to "handover of emergency bearer services" and: i) the selected PLMN is an equivalent PLMN, initiate an attach for emergency bearer services to the selected PLMN; and ii) the selected PLMN is not an equivalent PLMN, perform a PLMN selection and initiate an attach for emergency bearer services to the selected PLMN if an attach for emergency bearer services was not already attempted with the selected PLMN. In a shared network, if the attach request for emergency bearer services fails due to abnormal case a) in clause .2.6, the UE shall perform the actions as described in clause 5.5.1.2.6 and shall: a) inform the upper layers of the failure to access the network; or NOTE 6: This can result in the upper layers requesting establishment of a CS emergency call (if not already attempted in the CS domain), or other implementation specific mechanisms, e.g. procedures specified in 3GPP TS 24.229[ IP multimedia call control protocol based on Session Initiation Protocol (SIP) and Session Description Protocol (SDP); Stage 3 ]  [13D] can result in the emergency call being attempted to another IP-CAN . b) attempt to perform a PLMN selection in the shared network and, if an attach for emergency bearer services was not already attempted with the selected PLMN and the ATTACH REQUEST message: - did not include a PDN CONNECTIVITY REQUEST message with request type set to "handover of emergency bearer services", initiate an attach for emergency bearer services to the selected PLMN; or - did include a PDN CONNECTIVITY REQUEST message with request type set to "handover of emergency bearer services" and: i) the selected PLMN is an equivalent PLMN, initiate an attach for emergency bearer services to the selected PLMN; and ii) the selected PLMN is not an equivalent PLMN, perform a PLMN selection and initiate an attach for emergency bearer services to the selected PLMN if an attach for emergency bearer services was not already attempted with the selected PLMN. In a shared network, if the attach request for emergency bearer services fails due to abnormal cases b), c) or d) in clause .2.6, the UE shall perform the actions as described in clause 5.5.1.2.6, and shall: a) inform the upper layers of the failure of the procedure; or NOTE 7: This can result in the upper layers requesting establishment of a CS emergency call (if not already attempted in the CS domain), or other implementation specific mechanisms, e.g. procedures specified in 3GPP TS 24.229[ IP multimedia call control protocol based on Session Initiation Protocol (SIP) and Session Description Protocol (SDP); Stage 3 ]  [13D] can result in the emergency call being attempted to another IP-CAN . b) attempt to perform a PLMN selection in the shared network and, if an attach for emergency bearer services was not already attempted with the selected PLMN and the ATTACH REQUEST message - did not include a PDN CONNECTIVITY REQUEST message with request type set to "handover of emergency bearer services", initiate an attach for emergency bearer services to the selected PLMN; or - did include a PDN CONNECTIVITY REQUEST message with request type set to "handover of emergency bearer services" and: i) the selected PLMN is an equivalent PLMN, initiate an attach for emergency bearer services to the selected PLMN; and ii) the selected PLMN is not an equivalent PLMN, perform a PLMN selection and initiate an attach for emergency bearer services to the selected PLMN if an attach for emergency bearer services was not already attempted with the selected PLMN.