Section: 5.5.1.2.4 Attach accepted by the network
Content: During an attach for emergency bearer services, if not restricted by local regulations, the MME shall not check for mobility and access restrictions, regional restrictions, subscription restrictions, or perform CSG access control when processing the ATTACH REQUEST message. The network shall not apply subscribed APN based congestion control during an attach procedure for emergency bearer services. During an attach for access to RLOS, the MME shall not check for access restrictions, regional restrictions and subscription restrictions when processing the ATTACH REQUEST message. If the attach request is accepted by the network, the MME shall send an ATTACH ACCEPT message to the UE and start timer T3450. If the attach request included the PDN CONNECTIVITY REQUEST message in the ESM message container information element to request PDN connectivity, the MME when accepting the attach request shall: - send the ATTACH ACCEPT message together with an ESM DUMMY MESSAGE contained in the ESM message container information element and discard the ESM message container information element included in the attach request if: - the UE indicated support of EMM-REGISTERED without PDN connection in the UE network capability IE of the ATTACH REQUEST message; - the MME supports EMM-REGISTERED without PDN connection and PDN connection is restricted according to the user's subscription data; - the attach type is not set to "EPS emergency attach" or "EPS RLOS attach"; and - the request type of the UE requested PDN connection is not set to "handover of emergency bearer services", "emergency" or "RLOS"; - otherwise, send the ATTACH ACCEPT message together with an ACTIVATE DEFAULT EPS BEARER CONTEXT REQUEST message contained in the ESM message container information element to activate the default bearer (see clause 6.4.1). In WB-S1 mode, the network may also initiate the activation of dedicated bearers towards the UE by invoking the dedicated EPS bearer context activation procedure (see clause 6.4.2). In NB-S1 mode the network shall not initiate the activation of dedicated bearers. If EMM-REGISTERED without PDN connection is supported by the UE and the MME, and the UE included an ESM DUMMY MESSAGE in the ESM message container information element of the ATTACH REQUEST message, the MME shall send the ATTACH ACCEPT message together with an ESM DUMMY MESSAGE contained in the ESM message container information element. If the attach request is accepted by the network, the MME shall delete the stored UE radio capability information or the UE radio capability ID, if any. In NB-S1 mode, if the attach request is accepted by the network, the MME shall set the EMC BS bit to zero in the EPS network feature support IE included in the ATTACH ACCEPT message to indicate that support of emergency bearer services in NB-S1 mode is not available. If the UE has included the UE network capability IE or the MS network capability IE or both in the ATTACH REQUEST message, the MME shall store all octets received from the UE, up to the maximum length defined for the respective information element. NOTE 1: This information is forwarded to the new MME during inter-MME handover or to the new SGSN during inter-system handover to A/Gb mode or Iu mode. NOTE 2: For further details concerning the handling of the MS network capability and UE network capability in the MME see also 3GPP TS 23.401[ General Packet Radio Service (GPRS) enhancements for Evolved Universal Terrestrial Radio Access Network (E-UTRAN) access ]  [10]. If the UE specific DRX parameter was included in the DRX Parameter IE in the ATTACH REQUEST message, the MME shall replace any stored UE specific DRX parameter with the received parameter and use it for the downlink transfer of signalling and user data in WB-S1 mode. In NB-S1 mode, if the DRX parameter in NB-S1 mode IE was included in the ATTACH REQUEST message, the MME shall provide to the UE the Negotiated DRX parameter in NB-S1 mode IE in the ATTACH ACCEPT message. The MME shall replace any stored UE specific DRX parameter in NB-S1 mode with the negotiated DRX parameter and use it for the downlink transfer of signalling and user data in NB-S1 mode. NOTE 3: In NB-S1 mode, if a DRX parameter was included in the Negotiated DRX parameter in NB-S1 mode IE in the ATTACH ACCEPT message, then the UE stores and uses the received DRX parameter in NB-S1 mode (see 3GPP TS 36.304[ Evolved Universal Terrestrial Radio Access (E-UTRA); User Equipment (UE) procedures in idle mode ]  [21]). If the UE did not receive a DRX parameter in the Negotiated DRX parameter in NB-S1 mode IE, or if the Negotiated DRX parameter in NB-S1 mode IE was not included in the ATTACH ACCEPT message, then the UE uses the cell specific DRX value in NB-S1 mode (see 3GPP TS 36.304[ Evolved Universal Terrestrial Radio Access (E-UTRA); User Equipment (UE) procedures in idle mode ]  [21]). In NB-S1 mode, if the UE requested "SMS only" in the Additional update type IE, supports NB-S1 mode only and the MME decides to accept the attach request for EPS services and "SMS only", the MME shall indicate "SMS only" in the Additional update result IE and shall set the EPS attach result IE to "EPS only" in the ATTACH ACCEPT message. The MME shall include the extended DRX parameters IE in the ATTACH ACCEPT message only if the extended DRX parameters IE was included in the ATTACH REQUEST message, and the MME supports and accepts the use of eDRX. If - the UE supports WUS assistance; and - the MME supports and accepts the use of WUS assistance, then the MME shall determine the negotiated UE paging probability information for the UE, store it in the EMM context of the UE, and if the UE is not attaching for emergency bearer services, the MME shall include it in the Negotiated WUS assistance information IE in the ATTACH ACCEPT message. The MME may take into account the UE paging probability information received in the Requested WUS assistance information IE when determining the negotiated UE paging probability information for the UE. NOTE 4: Besides the UE paging probability information requested by the UE, the MME can take local configuration or previous statistical information for the UE into account when determining the negotiated UE paging probability information for the UE (see 3GPP TS 23.401[ General Packet Radio Service (GPRS) enhancements for Evolved Universal Terrestrial Radio Access Network (E-UTRAN) access ]  [10]). The MME shall assign and include the TAI list the UE is registered to in the ATTACH ACCEPT message. The MME shall not assign a TAI list containing both tracking areas in NB-S1 mode and tracking areas in WB-S1 mode. The UE, upon receiving an ATTACH ACCEPT message, shall delete its old TAI list and store the received TAI list. NOTE 5: When assigning the TAI list, the MME can take into account the eNodeB's capability of support of CIoT EPS optimization. The MME may include T3412 extended value IE in the ATTACH ACCEPT message only if the UE indicates support of the extended periodic timer T3412 in the MS network feature support IE in the ATTACH REQUEST message. The MME shall include the T3324 value IE in the ATTACH ACCEPT message only if the T3324 value IE was included in the ATTACH REQUEST message, and the MME supports and accepts the use of PSM. If the MME supports and accepts the use of PSM, and the UE included the T3412 extended value IE in the ATTACH REQUEST message, then the MME shall take into account the T3412 value requested when providing the T3412 value IE and the T3412 extended value IE in the ATTACH ACCEPT message. NOTE 6: Besides the value requested by the UE, the MME can take local configuration or subscription data provided by the HSS into account when selecting a value for T3412 (3GPP TS 23.401[ General Packet Radio Service (GPRS) enhancements for Evolved Universal Terrestrial Radio Access Network (E-UTRAN) access ]  [10] clause 4.3.17.3). If the UE indicates support for EMM-REGISTERED without PDN connection in the ATTACH REQUEST message and the MME supports EMM-REGISTERED without PDN connection, the MME shall indicate support for EMM-REGISTERED without PDN connection in the EPS network feature support IE of the ATTACH ACCEPT message. The UE and the MME shall use the information whether the peer entity supports EMM-REGISTERED without PDN connection as specified in the present clause 5 and in clause 6. If the UE requests "control plane CIoT EPS optimization" in the Additional update type IE, indicates support of control plane CIoT EPS optimization in the UE network capability IE and the MME decides to accept the requested CIoT EPS optimization and the attach request, the MME shall indicate "control plane CIoT EPS optimization supported" in the EPS network feature support IE. If the UE indicates support for enhanced discontinuous coverage in the ATTACH REQUEST message, and the MME supports enhanced discontinuous coverage, the MME shall indicate "Enhanced discontinuous coverage supported" in the EPS network feature support IE of the ATTACH ACCEPT message. If the MME supports NB-S1 mode, non-IP or Ethernet PDN type, inter-system change with 5GS, UAS services or the network wants to enforce the use of DNS over (D)TLS (see 3GPP TS 33.501[ Security architecture and procedures for 5G System ]  [24]), then the MME shall support the Extended protocol configuration options IE. NOTE 7: Support of DNS over (D)TLS is based on the informative requirements as specified in 3GPP TS 33.401[ 3GPP System Architecture Evolution (SAE); Security architecture ]  [19] and it is implemented based on the operator requirement. If the MME supports the Extended protocol configuration options IE and the UE indicated support of the Extended protocol configuration options IE, then the MME shall set the ePCO bit to "extended protocol configuration options supported" in the EPS network feature support IE of the ATTACH ACCEPT message. If the UE indicates support for restriction on use of enhanced coverage in the ATTACH REQUEST message, and the network decides to restrict the use of enhanced coverage for the UE, then the MME shall set the RestrictEC bit to "Use of enhanced coverage is restricted" in the EPS network feature support IE of the ATTACH ACCEPT message. If the UE has indicated support for the control plane data back-off timer, and the MME decides to activate the congestion control for transport of user data via the control plane, then the MME shall include the T3448 value IE in the ATTACH ACCEPT message. If the UE indicates support for dual connectivity with NR in the ATTACH REQUEST message, and the MME decides to restrict the use of dual connectivity with NR for the UE, then the MME shall set the RestrictDCNR bit to "Use of dual connectivity with NR is restricted" in the EPS network feature support IE of the ATTACH ACCEPT message. If the UE indicates support for N1 mode in the ATTACH REQUEST message and the MME supports inter-system interworking with 5GS, the MME may set the IWK N26 bit to either: - "interworking without N26 interface not supported" if the MME supports N26 interface; or - "interworking without N26 interface supported" if the MME does not support N26 interface in the EPS network feature support IE in the ATTACH ACCEPT message. If the UE requests ciphering keys for ciphered broadcast assistance data in the ATTACH REQUEST message and the MME has valid ciphering key data applicable to the UE's subscription, then the MME shall include the ciphering key data in the Ciphering key data IE of the ATTACH ACCEPT message. If the UE indicates support of the NAS signalling connection release in the ATTACH REQUEST message and the network decides to accept the NAS signalling connection release, then the MME shall set the NAS signalling connection release bit to "NAS signalling connection release supported" in the EPS network feature support IE of the ATTACH ACCEPT message. If the UE indicates support of the paging indication for voice services in the ATTACH REQUEST message and the network decides to accept the paging indication for voice services, then the MME shall set the paging indication for voice services bit to "paging indication for voice services supported" in the EPS network feature support IE of the ATTACH ACCEPT message. Upon receipt of ATTACH ACCEPT message with the paging indication for voice services bit set to "paging indication for voice services supported", the UE NAS layer informs the lower layers that paging indication for voice services is supported. Otherwise, the UE NAS layer informs the lower layers that paging indication for voice services is not supported. If the UE indicates support of the reject paging request in the ATTACH REQUEST message and the network decides to accept the reject paging request, then the MME shall set the reject paging request bit to "reject paging request supported" in the EPS network feature support IE of the ATTACH ACCEPT message. If the UE indicates support of the paging restriction in the ATTACH REQUEST message, and the MME sets: - the reject paging request bit to "reject paging request supported"; - the NAS signalling connection release bit to "NAS signalling connection release supported"; or - both of them; in the EPS network feature support IE of the ATTACH ACCEPT message, and the network decides to accept the paging restriction, then the MME shall set the paging restriction bit to "paging restriction supported" in the EPS network feature support IE of the ATTACH ACCEPT message. If the UE indicates support of the paging timing collision control in the ATTACH REQUEST message and the network decides to accept the paging timing collision control, then the MME shall set the paging timing collision control bit to "paging timing collision control supported" in the EPS network feature support IE of the ATTACH ACCEPT message. If the MUSIM UE has included a Requested IMSI offset IE in the ATTACH REQUEST message and if the MME supports paging timing collision control, the MME shall include the Negotiated IMSI offset IE in the ATTACH ACCEPT message, and the MME shall set the IMSI offset value to: - A value that is different than what the UE has provided, if the MME has a different value; or - A value that is same as what the UE has provided, if the MME does not have a different value; and the MME shall calculate an alternative IMSI value using the IMSI offset value and store it in the UE context as specified in 3GPP TS 23.401[ General Packet Radio Service (GPRS) enhancements for Evolved Universal Terrestrial Radio Access Network (E-UTRAN) access ]  [10]. The alternative IMSI value is used for deriving the paging occasion as specified in 3GPP TS 36.304[ Evolved Universal Terrestrial Radio Access (E-UTRA); User Equipment (UE) procedures in idle mode ]  [21]. If the MUSIM UE has not included a Requested IMSI offset IE in the ATTACH REQUEST message, the MME shall erase any stored alternative IMSI value for that UE, if available. The MME shall set the redir-policy bit to "Unsecured redirection to GERAN or UTRAN not allowed" in the Network policy IE of the ATTACH ACCEPT message if unsecured redirection to a GERAN or UTRAN cell is not allowed in the current PLMN. Otherwise, the redir-policy bit shall be set to "Unsecured redirection to GERAN or UTRAN allowed". The MME may include the T3447 value IE set to the service gap time value in the ATTACH ACCEPT message if: - the UE has indicated support for service gap control; and - a service gap time value is available in the EMM context. If the network supports signalling for a maximum number of 15 EPS bearer contexts and the UE indicated support of signalling for a maximum number of 15 EPS bearer contexts in the ATTACH REQUEST message, then the MME shall set the 15 bearers bit to "Signalling for a maximum number of 15 EPS bearer contexts supported" in the EPS network feature support IE of the ATTACH ACCEPT message. Upon receiving the ATTACH ACCEPT message, the UE shall stop timer T3410. The GUTI reallocation may be part of the attach procedure. When the ATTACH REQUEST message includes the IMSI or IMEI, or the MME considers the GUTI provided by the UE is invalid, or the GUTI provided by the UE was assigned by another MME, the MME shall allocate a new GUTI to the UE. The MME shall include in the ATTACH ACCEPT message the new assigned GUTI together with the assigned TAI list. In this case the MME shall enter state EMM-COMMON-PROCEDURE-INITIATED as described in clause 5.4.1. For a shared network, the TAIs included in the TAI list can contain different PLMN identities. The MME indicates the selected core network operator PLMN identity to the UE in the GUTI (see 3GPP TS 23.251[ Network sharing; Architecture and functional description ]  [8B]). If the ATTACH ACCEPT message contains a GUTI, the UE shall use this GUTI as the new temporary identity. The UE shall delete its old GUTI and store the new assigned GUTI. If no GUTI has been included by the MME in the ATTACH ACCEPT message, the old GUTI, if any available, shall be kept. If A/Gb mode or Iu mode is supported in the UE, the UE shall set its TIN to "GUTI" when receiving the ATTACH ACCEPT message. If the ATTACH ACCEPT message contains the T3412 extended value IE, then the UE shall use the value in T3412 extended value IE as periodic tracking area update timer (T3412). If the ATTACH ACCEPT message does not contain T3412 extended value IE, then the UE shall use the value in T3412 value IE as periodic tracking area update timer (T3412). If the ATTACH ACCEPT message contains the T3324 value IE, then the UE shall use the included timer value for T3324 as specified in 3GPP TS 24.008[ Mobile radio interface Layer 3 specification; Core network protocols; Stage 3 ]  [13], clause 4.7.2.8. If the ATTACH ACCEPT message contains the DCN-ID IE, then the UE shall store the included DCN-ID value together with the PLMN code of the registered PLMN in a DCN-ID list in a non-volatile memory in the ME as specified in annex C. If the ATTACH ACCEPT message contains Negotiated IMSI offset IE, the MUSIM UE shall forward the IMSI offset value to lower layers. If the ATTACH ACCEPT message does not contain Negotiated IMSI offset IE, the MUSIM UE shall indicate to lower layers to erase any IMSI offset value, if available. The MME may also include a list of equivalent PLMNs in the ATTACH ACCEPT message. Each entry in the list contains a PLMN code (MCC+MNC). The UE shall store the list as provided by the network, and if the attach procedure is neither for emergency bearer services nor for access to RLOS, the UE shall remove from the list any PLMN code that is already in the list of "forbidden PLMNs" or in the list of "forbidden PLMNs for GPRS service". In addition, the UE shall add to the stored list the PLMN code of the registered PLMN that sent the list. The UE shall replace the stored list on each receipt of the ATTACH ACCEPT message. If the ATTACH ACCEPT message does not contain a list, then the UE shall delete the stored list. If the MME received the list of TAIs from the satellite E-UTRAN as described in 3GPP TS 23.401[ General Packet Radio Service (GPRS) enhancements for Evolved Universal Terrestrial Radio Access Network (E-UTRAN) access ]  [10], and determines that, by UE subscription and operator's preferences, any but not all TAIs in the received list of TAIs is forbidden for roaming or for regional provision of service, the MME shall include the TAI(s) in: a) the Forbidden TAI(s) for the list of "Forbidden tracking areas for roaming" IE; b) the Forbidden TAI(s) for the list of "Forbidden tracking areas for regional provision of service" IE; or c) both, in the ATTACH ACCEPT message. If the attach procedure is neither for emergency bearer services nor for access to RLOS, and if the PLMN identity of the registered PLMN is a member of the list of "forbidden PLMNs" or the list of "forbidden PLMNs for GPRS service", any such PLMN identity shall be deleted from the corresponding list(s). The network informs the UE about the support of specific features, such as IMS voice over PS session, location services (EPC-LCS, CS-LCS), emergency bearer services, or CIoT EPS optimizations, in the EPS network feature support information element. In a UE with IMS voice over PS capability, the IMS voice over PS session indicator and the emergency bearer services indicator shall be provided to the upper layers. The upper layers take the IMS voice over PS session indicator into account as specified in 3GPP TS 23.221[ Architectural requirements ]  [8A], clause 7.2a and clause 7.2b, when selecting the access domain for voice sessions or calls. When initiating an emergency call, the upper layers also take both the IMS voice over PS session indicator and the emergency bearer services indicator into account for the access domain selection. In a UE with LCS capability, location services indicators (EPC-LCS, CS-LCS) shall be provided to the upper layers. When MO-LR procedure is triggered by the UE's application, those indicators are taken into account as specified in 3GPP TS 24.171[ Control Plane Location Services (LCS) procedures in the Evolved Packet System (EPS) ]  [13C]. If the RestrictDCNR bit is set to "Use of dual connectivity with NR is restricted" in the EPS network feature support IE of the ATTACH ACCEPT message, the UE shall provide the indication that dual connectivity with NR is restricted to the upper layers. The UE supporting N1 mode shall operate in the mode for inter-system interworking with 5GS as follows: - if the IWK N26 bit in the EPS network feature support IE is set to "interworking without N26 interface not supported", the UE shall operate in single-registration mode; - if the IWK N26 bit in the EPS network feature support IE is set to "interworking without N26 interface supported" and the UE supports dual-registration mode, the UE may operate in dual-registration mode; or NOTE 9: The registration mode used by the UE is implementation dependent. - if the IWK N26 bit in the EPS network feature support IE is set to "interworking without N26 interface supported" and the UE only supports single-registration mode, the UE shall operate in single-registration mode. The UE shall treat the interworking without N26 interface indicator as valid in the entire PLMN and equivalent PLMNs. The interworking procedures required for coordination between 5GMM and EMM without N26 interface are specified in 3GPP TS 24.501[ Non-Access-Stratum (NAS) protocol for 5G System (5GS); Stage 3 ]  [54]. If the redir-policy bit is set to "Unsecured redirection to GERAN or UTRAN not allowed" in the Network policy IE of the ATTACH ACCEPT message, the UE shall set the network policy on unsecured redirection to GERAN or UTRAN for the current PLMN to "Unsecured redirection to GERAN or UTRAN not allowed" and indicate to the lower layers that unsecured redirection to a GERAN or UTRAN cell is not allowed. If the redir-policy bit is set to "Unsecured redirection to GERAN or UTRAN allowed" or if the Network policy IE is not included in the ATTACH ACCEPT message, the UE shall set the network policy for the current PLMN to "Unsecured redirection to GERAN or UTRAN allowed" and indicate to the lower layers that unsecured redirection to a GERAN or UTRAN cell is allowed. The UE shall set the network policy on unsecured redirection to GERAN or UTRAN to "Unsecured redirection to GERAN or UTRAN not allowed" and indicate this to the lower layers when any of the following events occurs: - the UE initiates an EPS attach or tracking area updating procedure in a PLMN different from the PLMN where the UE performed the last successful EPS attach or tracking area updating procedure; - the UE is switched on; or - the UICC containing the USIM is removed. If the UE has initiated the attach procedure due to manual CSG selection and receives an ATTACH ACCEPT message; and the UE sent the ATTACH REQUEST message in a CSG cell, the UE shall check if the CSG ID and associated PLMN identity of the cell are contained in the Allowed CSG list. If not, the UE shall add that CSG ID and associated PLMN identity to the Allowed CSG list and the UE may add the HNB Name (if provided by lower layers) to the Allowed CSG list if the HNB Name is present in neither the Operator CSG list nor the Allowed CSG list. When the UE receives the ATTACH ACCEPT message combined with the ACTIVATE DEFAULT EPS BEARER CONTEXT REQUEST message, and if the UE has requested PDN connectivity the UE shall forward the ACTIVATE DEFAULT EPS BEARER CONTEXT REQUEST message to the ESM sublayer. Upon receipt of an indication from the ESM sublayer that the default EPS bearer context has been activated, the UE shall send an ATTACH COMPLETE message together with an ACTIVATE DEFAULT EPS BEARER CONTEXT ACCEPT message contained in the ESM message container information element to the network. Additionally, the UE shall reset the attach attempt counter, enter state EMM-REGISTERED, and set the EPS update status to EU1 UPDATED. If EMM-REGISTERED without PDN connection is supported by the UE and the MME, and the UE receives the ATTACH ACCEPT message combined with an ESM DUMMY MESSAGE, the UE shall send an ATTACH COMPLETE message together with an ESM DUMMY MESSAGE contained in the ESM message container information element to the network. If the UE receives the ATTACH ACCEPT message from a PLMN for which a PLMN-specific attempt counter or PLMN-specific PS-attempt counter is maintained (see clause 5.3.7b), then the UE shall reset these counters. If the UE maintains a counter for "SIM/USIM considered invalid for GPRS services", then the UE shall reset this counter. When the UE receives any ACTIVATE DEDICATED EPS BEARER CONTEXT REQUEST messages during the attach procedure, and if the UE has requested PDN connectivity the UE shall forward the ACTIVATE DEDICATED EPS BEARER CONTEXT REQUEST message(s) to the ESM sublayer. The UE shall send a response to the ACTIVATE DEDICATED EPS BEARER CONTEXT REQUEST message(s) after successful completion of the attach procedure. If the attach procedure was initiated in S101 mode, the lower layers are informed about the successful completion of the procedure. NOTE 10: For the UE supporting non-IP or Ethernet PDN type or UAS services, if the UE receives the ATTACH ACCEPT message and the ePCO bit in the EPS network feature support IE is not set to "extended protocol configuration options supported", the UE can perform a PLMN selection according to 3GPP TS 23.122[ Non-Access-Stratum (NAS) functions related to Mobile Station (MS) in idle mode ]  [6] with the current PLMN considered as the lowest priority after the completion of the attach procedure. Upon receiving an ATTACH COMPLETE message, the MME shall stop timer T3450, enter state EMM-REGISTERED and consider the GUTI sent in the ATTACH ACCEPT message as valid. If the T3448 value IE is present in the received ATTACH ACCEPT message, the UE shall: - stop timer T3448 if it is running; and - start timer T3448 with the value provided in the T3448 value IE. If the UE is using EPS services with control plane CIoT EPS optimization, the T3448 value IE is present in the ATTACH ACCEPT message and the value indicates that this timer is either zero or deactivated, the UE shall consider this case as an abnormal case and proceed as if the T3448 value IE is not present. If the UE has indicated "service gap control supported" in the ATTACH REQUEST message and: - the ATTACH ACCEPT message contains the T3447 value IE, then the UE shall store the new T3447 value, erase any previous stored T3447 value if exists and use the new T3447 value with the T3447 timer next time it is started; or - the ATTACH ACCEPT message does not contain the T3447 value IE, then the UE shall erase any previous stored T3447 value if exists and stop the T3447 timer if running. In WB-S1 mode, if the UE has set the RACS bit to "RACS supported" in the UE network capability IE of the ATTACH REQUEST message, the MME may include a UE radio capability ID IE or a UE radio capability ID deletion indication IE in the ATTACH ACCEPT message. In WB-S1 mode, if the UE has set the RACS bit to "RACS supported" in the UE network capability IE of the ATTACH REQUEST message and the ATTACH ACCEPT message includes: - a UE radio capability ID deletion indication IE set to "Network-assigned UE radio capability IDs deletion requested", the UE shall delete any network-assigned UE radio capability IDs associated with the registered PLMN stored at the UE, then the UE shall, after the completion of the ongoing attach procedure, initiate a tracking area updating procedure as specified in clause 5.5.3 over the existing NAS signalling connection; or - a UE radio capability ID IE, the UE shall store the UE radio capability ID as specified in annex C. If the UE receives the Forbidden TAI(s) for the list of "forbidden tracking areas for roaming" IE in the ATTACH ACCEPT message, the UE shall store the TAI(s) included in the IE which are belonging to the serving PLMN or equivalent PLMN(s), if not already stored, into the list of "forbidden tracking areas for roaming" and ignore the TAI(s) which do not belong to the serving PLMN or equivalent PLMN(s). If the UE receives the Forbidden TAI(s) for the list of "forbidden tracking areas for regional provision of service" IE in the ATTACH ACCEPT message, the UE shall store the TAI(s) included in the IE which are belonging to the serving PLMN or equivalent PLMN(s), if not already stored, into the list of "forbidden tracking areas for regional provision of service" and ignore the TAI(s) which do not belong to the serving PLMN or equivalent PLMN(s). If for discontinuous coverage, the UE receives the Unavailability configuration IE in the ATTACH ACCEPT message and the End of unavailability report bit is set to "UE does not need to report end of unavailability", the UE is not required to trigger tracking area update procedure when the unavailability period duration has ended. If the UE does not receive the Unavailability configuration IE or the End of unavailability report bit is set to "UE needs to report end of unavailability", the UE should trigger tracking area update procedure when the unavailability period duration has ended.