Section: 6.4.4.6 Local EPS bearer context deactivation without NAS signalling
Content: The UE and the MME deactivate EPS bearer contexts locally without peer-to-peer ESM signalling in the following cases: 1) during the service request procedure, if the E-UTRAN establishes the user plane radio bearers for one or more EPS bearer contexts but not for all the EPS bearer contexts, e.g. due to radio access control (see clause 5.6.1.4 for details); 1a) during the resume of NAS signalling connection procedure as specified in clause 5.3.1.3, if one or more but not all the suspended user plane radio bearers are resumed; 2) during the tracking area updating procedure but the network established the user plane radio bearers due to downlink pending data, if the E-UTRAN establishes the user plane radio bearers for one or more EPS bearer contexts but not for all the EPS bearer contexts indicated active by both UE and network; NOTE 1: The synchronisation of the EPS bearers, for which the user plane radio bearers need to be established, indicated in EPS bearer context status information element in TRACKING AREA UPDATE ACCEPT message is not applicable in item 2. 3) during handover, if the target E-UTRAN does not establish all the user plane radio bearers for the UE; 4) if the E-UTRAN releases one or more user plane radio bearers but not all the user plane radio bearers of the UE due to E-UTRAN specific reasons; or 5) if triggered by an NBIFOM procedure (see 3GPP TS 24.161[ Network-Based IP Flow Mobility (NBIFOM); Stage 3 ]  [36]), for an NBIFOM multi-access PDN connection. For cases 1) to 4), based on the indication from the lower layers, the UE and the MME shall locally deactivate the EPS bearer contexts for which no user plane radio bearers are set up. NOTE 2: The above cases 1) to 4) do not apply for the UE when an RRC connection release occurs. The lower layers in the UE provide the user plane radio bearer context status to the ESM sublayer when a change in the user plane radio bearers is detected by the lower layers including establishment and release of user plane radio bearers for the UE in connected mode. NOTE 3: The above cases 1) to 4) do not apply for the MME when the S1 release procedure occurs as specified in 3GPP TS 23.401[ General Packet Radio Service (GPRS) enhancements for Evolved Universal Terrestrial Radio Access Network (E-UTRAN) access ]  [10]). If due to any of the cases described above the UE locally deactivates a default EPS bearer context, the UE shall locally deactivate all EPS bearer contexts associated to the PDN connection with the default EPS bearer context. If the UE locally deactivates the EPS bearer context(s) of the last remaining PDN connection, and EMM-REGISTERED without PDN connection is not supported by the UE or the MME, the UE shall perform a local detach and enter state EMM-DEREGISTERED. If this occurs during a service request procedure for CS fallback, the UE shall reselect to GERAN or UTRAN and continue with the CS service, otherwise the UE shall initiate an attach procedure. If the UE locally deactivates the EPS bearer context(s) of the last remaining PDN connection, and EMM-REGISTERED without PDN connection is supported by the UE and the MME, the UE shall enter state EMM-REGISTERED. If the UE locally deactivates the EPS bearer context(s) of the last remaining PDN connection for non-emergency bearer services and only the PDN connection for emergency bearer services remains established, the UE shall consider itself attached for emergency bearer services only. The MME shall deactivate the GBR EPS bearer contexts locally without peer-to-peer ESM signalling, when the MME performs locally the release of the S1AP signalling connection due to the S1AP signalling connection is lost. All non-GBR EPS bearers established are preserved in the MME and in the PDN GW. If the E-UTRAN requests the MME to release the S1AP signalling connection, the MME shall deactivate or preserve the GBR EPS bearer contexts according to 3GPP TS 23.401[ General Packet Radio Service (GPRS) enhancements for Evolved Universal Terrestrial Radio Access Network (E-UTRAN) access ]  [10], clause 5.3.5. All non-GBR EPS bearer contexts established are preserved in the MME and in the PDN GW. NOTE 4: The UE and the MME will synchronize the EPS bearer contexts subsequently during the next service request procedure, tracking area updating procedure or routing area updating procedure. If due to any of the cases described above the MME locally deactivates a default EPS bearer context, the MME shall locally deactivate all EPS bearer contexts associated to the PDN connection with the default EPS bearer context without peer-to-peer ESM signalling to the UE. If the MME locally deactivates the EPS bearer context(s) of the last remaining PDN connection, and EMM-REGISTERED without PDN connection is not supported by the UE or the MME, the MME shall perform a local detach and enter state EMM-DEREGISTERED. If the MME locally deactivates the EPS bearer context(s) of the last remaining PDN connection, and EMM-REGISTERED without PDN connection is supported by the UE and the MME, the MME shall enter state EMM-REGISTERED. For EPS bearer context deactivation procedure initiated by the network, if no NAS signalling connection exists, the MME locally deactivates the EPS bearer context(s) without peer-to-peer ESM signalling In the case of reactivation requested, the MME can perform this local deactivation only when the EMM-entity in the network was unable to re-establish the NAS signalling connection. The EPS bearer context deactivation procedure is not initiated by the network when the MME disconnects the UE from the last remaining PDN to which it is connected and EMM-REGISTERED without PDN connection is not supported by the UE or the MME. In this case, the MME initiates a network initiated detach procedure. If the MME locally deactivates the EPS bearer context(s) of the last remaining PDN connection for non-emergency bearer services and only the PDN connection for emergency bearer services remains established for the UE, the MME shall consider the UE to be attached for emergency bearer services only.