Section: 5.5.1.3.4.2 Combined attach successful
Content: The description for attach for EPS services as specified in clause 5.5.1.2.4 shall be followed. In addition, the following description for attach for non-EPS services or "SMS only" applies. The TMSI reallocation may be part of the combined attach procedure. The TMSI allocated is then included in the ATTACH ACCEPT message, together with the location area identification (LAI). In this case the MME shall start timer T3450 as described in clause 5.4.1.4, and enter state EMM-COMMON-PROCEDURE-INITIATED. If the MME does not indicate "SMS only" in the ATTACH ACCEPT message, subject to operator policies the MME should allocate a TAI list that does not span more than one location area. For a shared network in CS domain, the MME indicates the selected PLMN for CS domain in the LAI to the UE as specified in 3GPP TS 23.272[ Circuit Switched (CS) fallback in Evolved Packet System (EPS); Stage 2 ]  [9]. The UE, receiving an ATTACH ACCEPT message, stores the received location area identification, stops timer T3410, resets the location update attempt counter and sets the update status to U1 UPDATED. If the message contains an IMSI, the UE is not allocated any TMSI, and shall delete any TMSI accordingly. If the message contains a TMSI, the UE shall use this TMSI as the new temporary identity. The UE shall delete its old TMSI and shall store the new TMSI. If neither a TMSI nor an IMSI has been included by the network in the ATTACH ACCEPT message, the old TMSI, if any available, shall be kept. If the UE maintains a counter for "SIM/USIM considered invalid for non-GPRS services" events (see clause 5.3.7b), then the UE shall reset this counter. If the UE requested "SMS only" in the Additional update type IE, or if the UE requested a combined attach for EPS and non-EPS services, but the network decides to accept the attach request for EPS services and "SMS only", the network shall indicate "SMS only" in the Additional update result IE. In addition, if the SMS services are provided via SMS in MME, the network shall provide a non-broadcast LAI in the ATTACH ACCEPT message. If a TMSI has to be allocated, then the network shall also provide a TMSI value which cannot cause any ambiguity with assigned TMSI values. If the ATTACH ACCEPT message includes the Additional update result IE with value "SMS only", a UE operating in CS/PS mode 2 and a UE operating in CS/PS mode 1 with "IMS voice available" shall not attempt to use CS fallback for mobile originating services. As an implementation option, if the ATTACH ACCEPT message does not include the Additional update result IE with value "SMS only" and the UE is not configured for NAS signalling low priority then the UE may stop timer T3246 if running. If the ATTACH ACCEPT message includes the Additional update result IE with value "CS Fallback not preferred", this indicates to a UE operating in CS/PS mode 2 and a UE operating in CS/PS mode 1 with "IMS voice available" that it is attached for EPS and non-EPS services and that it can use CS fallback. If the LAI contained in the ATTACH ACCEPT message is a member of the list of "forbidden location areas for regional provision of service" or the list of "forbidden location areas for roaming" then such entry shall be deleted. If the PLMN identity for the CS domain which is provided as part of the LAI contained in the ATTACH ACCEPT message differs from the PLMN identity provided as part of the GUTI, the MME shall include the PLMN identity for the CS domain in the list of equivalent PLMNs in the ATTACH ACCEPT message. The UE, when having requested PDN connectivity as contained in the ATTACH REQUEST message and on receiving the ATTACH ACCEPT message combined with the ACTIVATE DEFAULT EPS BEARER CONTEXT REQUEST message, shall send an ATTACH COMPLETE message combined with an ACTIVATE DEFAULT EPS BEARER CONTEXT ACCEPT message to the network. Upon transmission of the ATTACH COMPLETE message the UE shall enter state EMM-REGISTERED and MM state MM-IDLE and set the EPS update status to EU1 UPDATED. If the ATTACH ACCEPT message includes the Additional update result IE with value "SMS only" or "CS Fallback not preferred", a UE operating in CS/PS mode 1 with "IMS voice not available" shall attempt to select GERAN or UTRAN radio access technology and disable the E-UTRA capability (see clause 4.5). Upon receiving an ATTACH COMPLETE message, the MME shall stop timer T3450, enter state EMM-REGISTERED. NOTE: Upon receiving an ATTACH COMPLETE message, the MME sends an SGsAP-TMSI-REALLOCATION-COMPLETE message as specified in 3GPP TS 29.118[ Mobility Management Entity (MME) - Visitor Location Register (VLR) SGs interface specification ]  [16A]. After the UE performs intersystem change from N1 mode to S1 mode, if: - the network supports SRVCC for IMS emergency sessions (see 3GPP TS 23.216[ Single Radio Voice Call Continuity (SRVCC); Stage 2 ]  [8]); - the UE has an emergency PDN connection; - the UE has set the SRVCC to GERAN/UTRAN capability bit in the MS network capability IE to "SRVCC from UTRAN HSPA or E-UTRAN to GERAN/UTRAN supported; and - the MME has neither an IMEI nor an IMEISV for the UE; then the MME shall initiate the identification procedure (see clause 5.4.4) or the security mode control procedure (see clause 5.4.3) with the UE.