Section: 4.7.3.1.3 GPRS attach accepted by the network
Content: During an attach for emergency bearer services, if not restricted by local regulations, the network 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. If the GPRS attach request is accepted by the network, an ATTACH ACCEPT message is sent to the MS. In A/Gb mode, if the MS indicates support of integrity protection in the MS network capability IE in the ATTACH REQUEST message, and if the network supports integrity protection, then the network shall store all octets received from the MS in the MS network capability IE and in the MS Radio Access Capability IE, up to the maximum length defined for the respective information element. NOTE 1: The network needs to store the MS network capability IE and the MS Radio Access Capability IE exactly as received from the MS and network is not allowed to ignore the "higher" octets sent by the MS even if the network does not support any features indicated in the higher octets. Otherwise the replay check of the MS network capability and the MS Radio Access Capability will fail in the MS. In A/Gb mode, if a UMTS security context is available in the network and if the MS indicates support of integrity protection in the ATTACH REQUEST message and the network supports integrity protection, and if integrity protection of the ATTACH REQUEST message is successfully verified in the LLC layer in the network, then if the network decides to re-authenticate the MS or select a new integrity algorithm or ciphering algorithm, the network shall initiate an authentication and ciphering procedure. In A/Gb mode, if a UMTS security context is available in the network and if the MS indicates support of integrity protection in the ATTACH REQUEST message and the network supports integrity protection if integrity protection of the ATTACH REQUEST message is successfully verified in the LLC layer in the network , the network may decide to continue using the stored: GPRS GSM Kint integrity key, the GPRS GSM Kc128 ciphering key, the GPRS GSM ciphering algorithm and the GPRS GSM integrity algorithm in the LLC layer without initiating an authentication and ciphering procedure. If the MS and network continue to use the same ciphering mode as when the MS was previously attached to the network, ciphering or no ciphering, the ciphering mode is re-established without the need to run an authentication and ciphering procedure. The network shall replay the MS network capability IE and the MS radio access capability IE received from the MS in the ATTACH REQUEST message, by including the MS network capability IE and the MS radio access capability IE in the ATTACH ACCEPT message to the MS. The GMM layer in the network shall assign the stored GPRS GSM Kint key, the GPRS GSM Kc128 key, the GPRS GSM integrity algorithm and the GPRS GSM ciphering algorithm to the LLC layer. The GMM layer in the network shall then indicate to the LLC layer that it shall start integrity protection and ciphering in the LLC layer before sending the ATTACH ACCEPT message to the MS. If the integrity protection of the ATTACH REQUEST message is not successfully verified in the LLC layer or if the ATTACH REQUEST message is received without integrity protection, then the network shall progress the ATTACH REQUEST message and initiate an authentication and ciphering procedure in order to authenticate the MS and activate integrity protection and ciphering in the MS. In A/Gb mode, if a UMTS security context is available in the network and if the MS indicates support of integrity protection in the ATTACH REQUEST message and the network supports integrity protection, and if the network is not able to verify the message authentication code in the LLC layer protecting the ATTACH REQUEST message, due to the LLC layer at the network not having been configured yet with the integrity key and integrity algorithm for this MS, then the network shall progress the ATTACH REQUEST message at GMM layer anyway. If the CKSN included in the ATTACH REQUEST message belongs to an UMTS security context available in the network, then the network may re-establish integrity protection and ciphering of layer 3 signalling messages in the LLC layer without initiating an authentication and ciphering procedure. In A/Gb mode, if the MS indicates support of integrity protection of user plane data in the MS network capability IE in the ATTACH REQUEST message, and if the network supports and accepts integrity protection of user plane data, then the network shall indicate integrity protection of user plane data to the MS in the ATTACH ACCEPT message. The MS shall indicate to the LLC layer to start integrity protection of user plane data after the reception of the ATTACH ACCEPT message. The same GPRS GSM Kint key and the same GPRS GSM integrity algorithm used for integrity protection of layer 3 signalling messages shall be used for integrity protection of user plane data in the LLC layer. The network shall indicate to the LLC layer to start integrity protection of user plane data after sending off the ATTACH ACCEPT message to the MS. If the network does not indicate to the MS in the ATTACH ACCEPT message that it accepts the use of integrity protection of user plane, and if the MS does not accept such a network, then the MS shall detach from the network. The P-TMSI reallocation may be part of the GPRS attach procedure. When the ATTACH REQUEST includes the IMSI or IMEI, the SGSN shall allocate the P-TMSI. The P-TMSI that shall be allocated is then included in the ATTACH ACCEPT message together with the routing area identifier. The network shall, in this case, change to state GMM-COMMON-PROCEDURE-INITIATED and shall start timer T3350 as described in subclause 4.7.6. Furthermore, the network may assign a P-TMSI signature for the GMM context which is then also included in the ATTACH ACCEPT message. If the LAI or PLMN identity that has been transmitted in the ATTACH ACCEPT message is a member of any of the "forbidden" lists, any such entry shall be deleted. If the attach procedure is for emergency bearer services, the "forbidden" lists shall remain unchanged. Additionally, the network shall include the radio priority level to be used by the MS for mobile originated SMS transfer in the ATTACH ACCEPT message. In a shared network, if the MS is a network sharing supporting MS, the network shall indicate the PLMN identity of the CN operator that has accepted the GPRS attach request in the RAI contained in the ATTACH ACCEPT message; if the MS is a network sharing non-supporting MS, the network shall indicate the PLMN identity of the common PLMN (see 3GPP TS 23.251[ Network sharing; Architecture and functional description ]  [109]). If the PLMN identity of the common PLMN included in the RAI does not identify the CN operator that has accepted the GPRS attach request, the network may include the PLMN identity of the CN operator that has accepted the GPRS attach request in the ATTACH ACCEPT message. In a multi-operator core network (MOCN) with common GERAN, the network shall indicate in the RAI the common PLMN identity (see 3GPP TS 23.251[ Network sharing; Architecture and functional description ]  [109]). If the common PLMN identity included in the RAI does not identify the CN operator that has accepted the GPRS attach request, the network may include the PLMN identity of the CN operator that has accepted the GPRS attach request in the ATTACH ACCEPT message. If the MS has indicated in the ATTACH REQUEST message that it supports PS inter-RAT handover from GERAN to UTRAN Iu mode, the network may include in the ATTACH ACCEPT message a request to provide the Inter RAT information container. If the MS has included the MS network capability IE or the UE network capability IE or both in the ATTACH REQUEST message, the network shall store all octets received from the MS, up to the maximum length defined for the respective information element. NOTE 2: This information is forwarded to the new SGSN during inter-SGSN handover or to the new MME during intersystem handover to S1 mode. If the DRX parameter was included in the DRX Parameter IE in the ATTACH REQUEST message, the network shall replace any stored DRX parameter with the received parameter and use it for the downlink transfer of signalling and user data. The network 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 network supports and accepts the use of eDRX. In A/Gb mode, the Cell Notification information element shall be included in the ATTACH ACCEPT message by the network which indicates that the Cell Notification is supported by the network. In Iu mode, the network should prolong the PS signalling connection if the mobile station has indicated a follow-on request pending in ATTACH REQUEST. The network may also prolong the PS signalling connection without any indication from the mobile terminal. The MS, receiving an ATTACH ACCEPT message, stores the received routing area identification, stops timer T3310, resets the GPRS attach attempt counter, resets the routing area updating attempt counter, resets the service request attempt counter, enters state GMM-REGISTERED and sets the GPRS update status to GU1 UPDATED. If the message contains a P-TMSI, the MS shall use this P-TMSI as the new temporary identity for GPRS services. In this case, an ATTACH COMPLETE message is returned to the network. The MS shall delete its old P-TMSI and shall store the new one. If no P-TMSI has been included by the network in the ATTACH ACCEPT message, the old P-TMSI, if any available, shall be kept. If the message contains a P-TMSI signature, the MS shall use this P-TMSI signature as the new temporary signature for the GMM context. The MS shall delete its old P-TMSI signature, if any is available, and shall store the new one. If the message contains no P-TMSI signature, the old P-TMSI signature, if available, shall be deleted. If the network supports delivery of SMS via GPRS (3GPP TS 23.060[ General Packet Radio Service (GPRS); Service description; Stage 2 ]  [74]) and this delivery is enabled (see 3GPP TS 29.272[ Evolved Packet System (EPS); Mobility Management Entity (MME) and Serving GPRS Support Node (SGSN) related interfaces based on Diameter protocol ]  [150]), then the network shall include the Additional network feature support IE in the ATTACH ACCEPT message and set the GPRS-SMS indicator. If the network supports the extended protocol configuration options IE and the MS indicated support of the extended protocol configuration options IE, then the network shall include the Additional network feature support IE in the ATTACH ACCEPT message and set the ePCO IE indicator to "extended protocol configuration options IE supported". Upon receiving the ATTACH ACCEPT message an MS supporting S1 mode shall set the TIN to "P-TMSI". If the network has requested the provision of Inter RAT handover information, the MS shall return an ATTACH COMPLETE message including the Inter RAT handover information IE to the network. The network may also send a list of "equivalent PLMNs" in the ATTACH ACCEPT message. Each entry of the list contains a PLMN code (MCC+MNC). The mobile station shall store the list, as provided by the network, and if the GPRS attach procedure is not for emergency bearer services, any PLMN code that is already in the "forbidden PLMN" list shall be removed from the "equivalent PLMNs" list before it is stored by the mobile station. If the mobile station is operating in MS operation mode C or the mobile station is supporting S1 mode, it shall also remove any PLMN code that is already in the list of "forbidden PLMNs for GPRS service" before storing the list. In addition the mobile station shall add to the stored list the PLMN code of the registered PLMN that sent the list. All PLMNs in the stored list shall be regarded as equivalent to each other for PLMN selection, cell selection/re-selection and handover. The stored list in the mobile station shall be replaced on each occurrence of the ATTACH ACCEPT message. If no list is contained in the message, then the stored list in the mobile station shall be deleted. An MS attached for emergency bearer services shall delete the stored list when the MS enters the state GMM-DEREGISTERED. The list shall be stored in the mobile station while switched off so that it can be used for PLMN selection after switch on. The network 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 network supports and accepts the use of PSM. If the network supports and accepts the use of PSM, and the MS included the T3312 extended value IE in the ATTACH REQUEST message, then the network shall take into account the T3312 value requested when providing the Periodic RA update timer IE and the T3312 extended value IE in the ATTACH ACCEPT message. NOTE 3: Besides the value requested by the MS, the network can take local configuration into account when selecting a value for T3312 (see 3GPP TS 23.060[ General Packet Radio Service (GPRS); Service description; Stage 2 ]  [74] subclause 5.3.13.54). In A/Gb mode, if the MS indicates support for restriction on use of enhanced coverage in the ATTACH REQUEST message, and the network restricts enhanced coverage for the MS, then the network shall set the RestrictEC bit to "Enhanced coverage restricted" in the Additional network feature support IE of the ATTACH ACCEPT message. In Iu mode, if the network wishes to prolong the PS signalling connection (for example, if the mobile station has indicated "follow-on request pending" in ATTACH REQUEST message) the network shall indicate the "follow-on proceed" in the ATTACH ACCEPT message. If the network wishes to release the PS signalling connection, the network shall indicate "no follow-on proceed" in the ATTACH ACCEPT message. After that in Iu mode, the mobile station shall act according to the follow-on proceed flag included in the Attach result information element in the ATTACH ACCEPT message (see subclause 4.7.13). In A/Gb mode, if the ATTACH ACCEPT message contains the Cell Notification information element, then the MS shall start to use the LLC NULL frame to perform cell updates. The network receiving an ATTACH COMPLETE message stops timer T3350, changes to GMM-REGISTERED state and considers the P-TMSI sent in the ATTACH ACCEPT message as valid. If the ATTACH ACCEPT message contains the T3312 extended value IE, then the MS shall use the value in T3312 extended value IE as periodic routing area update timer (T3312). If the ATTACH ACCEPT message does not contain T3312 extended value IE, then the MS shall use the value in the Periodic RA update timer IE as periodic routing area update timer (T3312). If the ATTACH ACCEPT message contains the T3324 value IE, then the MS shall use the included timer value for T3324 as specified in subclause 4.7.2.8. If the ATTACH ACCEPT message contains the DCN-ID IE, then the MS 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 described in 3GPP TS 24.301[ Non-Access-Stratum (NAS) protocol for Evolved Packet System (EPS); Stage 3 ]  [120], annex C. In a shared network or in a multi-operator core network (MOCN) with common GERAN, if the ATTACH ACCEPT message contains the DCN-ID IE and the PLMN identity of the CN operator IE, the MS shall store the included DCN-ID value with the PLMN identity indicated in the PLMN identity of the CN operator IE, and the included DCN-ID value with the PLMN identity indicated in the RAI in a DCN-ID list in a non-volatile memory in the ME as described in 3GPP TS 24.301[ Non-Access-Stratum (NAS) protocol for Evolved Packet System (EPS); Stage 3 ]  [120], annex C. If the MS receives the ATTACH ACCEPT message from a PLMN for which a PLMN-specific attempt counter or PLMN-specific PS-attempt counter is maintained (see subclause 4.1.1.6A), then the MS shall reset these counters. If the MS maintains a counter for "SIM/USIM considered invalid for GPRS services", then the MS shall reset this counter. The network may also send a Local Emergency Numbers List with local emergency numbers in the ATTACH ACCEPT, by including the Emergency Number List IE. The mobile equipment shall store the Local Emergency Numbers List, as provided by the network. The Local Emergency Numbers List stored in the mobile equipment shall be replaced on each receipt of the Emergency Number List IE. The received Local Emergency Numbers List shall be provided to the upper layers. The emergency number(s) received in the Emergency Number List IE are valid only in networks in the same country as the cell on which this IE is received. If no list is contained in the ATTACH ACCEPT message, then the stored Local Emergency Numbers List in the mobile equipment shall be kept, except if the mobile equipment has successfully registered to a PLMN in a country different from that of the PLMN that sent the Local Emergency Numbers List. The mobile equipment shall use the stored Local Emergency Numbers List of emergency numbers received from the network in addition to the emergency numbers stored on the SIM/USIM or ME to detect that the number dialled is an emergency number. NOTE 4: The mobile equipment may use the Local Emergency Numbers List to assist the end user in determining whether the dialled number is intended for an emergency service or for another destination, e.g. a local directory service. The possible interactions with the end user are implementation specific. NOTE 5: An MS that supports procedures specified in 3GPP TS 24.302[ Access to the 3GPP Evolved Packet Core (EPC) via non-3GPP access networks; Stage 3 ]  [156], can get additional local emergency numbers through those procedures, which can be used based on operator policy (see 3GPP TS 24.302[ Access to the 3GPP Evolved Packet Core (EPC) via non-3GPP access networks; Stage 3 ]  [156]) to detect that the number dialled is an emergency number. The Local Emergency Numbers List shall be deleted at switch off and removal of the SIM/USIM. The mobile equipment shall be able to store up to ten local emergency numbers received from the network. If the MS has initiated the attach procedure due to manual CSG selection and receives an ATTACH ACCEPT message, and the MS sent the ATTACH REQUEST message in a CSG cell, the MS shall check if the CSG ID and associated PLMN identity of the cell are contained in the Allowed CSG list. If not, the MS shall add that CSG ID and associated PLMN identity to the Allowed CSG list and the MS 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. In A/Gb mode, if a UMTS security context is available, if the MS indicates support of integrity protection in the ATTACH REQUEST message and the network supports integrity protection, then if the MS receives replayed capabilities IE’s in ATTACH ACCEPT, then the MS shall check if the replayed MS network capability IE and replayed MS Radio Access Capability IE received in the ATTACH ACCEPT message has not been altered compared to the MS network capability IE and the MS Radio Access Capability IE that the MS sent to the network in ATTACH REQUEST message. If the replayed MS network capability IE and the replayed MS Radio Access Capability IE are not the same, then the MS shall ignore the ATTACH ACCEPT message.