Section: 4.7.3.2.3 Combined GPRS attach accepted by the network
Content: Depending on the value of the attach result IE received in the ATTACH ACCEPT message, two different cases can be distinguished: Case 1) The attach result IE value indicates "combined GPRS attach": IMSI attach for GPRS and non-GPRS services have been successful. Case 2) The attach result IE value indicates "GPRS only": IMSI attach for GPRS services has been successful but IMSI attach for non-GPRS services has not been successful. 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). 4.7.3.2.3.1 Combined attach successful for GPRS and non-GPRS services The description for IMSI attach for GPRS services as specified in subclause 4.7.3.1.3 shall be followed. In addition, the following description for IMSI attach for non-GPRS services applies. The TMSI reallocation may be part of the combined GPRS attach procedure. The TMSI allocated is then included in the ATTACH ACCEPT message together with the location area identification (LAI). 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. The MS, receiving an ATTACH ACCEPT message, stores the received location area identification, stops timer T3310, reset the location update attempt counter and sets the update status to U1 UPDATED. If the message contains an IMSI, the mobile station is not allocated any TMSI, and shall delete any TMSI accordingly. If the message contains a TMSI, the MS shall use this TMSI as the new temporary identity. The MS shall delete its old TMSI and shall store the new TMSI. In this case, an ATTACH COMPLETE message is returned to the network. 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. The new MM state is MM IDLE, the new GMM state is GMM-REGISTERED. If the MS maintains a counter for "SIM/USIM considered invalid for non-GPRS services" events (see subclause 4.1.1.6A), then the MS shall reset this counter. 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. If the MS is not configured for NAS signalling low priority then the MS may stop timer T3246 if running. Any timer used for triggering the location update procedure (e.g T3211, T3212) shall be stopped if running. The network receiving an ATTACH COMPLETE message stops timer T3350, changes to state GMM-REGISTERED. NOTE: Upon receiving an ATTACH COMPLETE message, the SGSN sends a BSSAP+-TMSI-REALLOCATION-COMPLETE message as specified in 3GPP TS 29.018[ General Packet Radio Service (GPRS); Serving GPRS Support Node (SGSN) - Visitors Location Register (VLR); Gs interface layer 3 specification ]  [149]. 4.7.3.2.3.2 Combined attach successful for GPRS services only Apart from the actions on the routing area updating attempt counter, the description for IMSI attach for GPRS services as specified in subclause 4.7.3.1.3 shall be followed. In addition, the following description for IMSI attach for non-GPRS services applies. The SGSN shall use GMM cause #28 "SMS provided via GPRS in this routing area" in the ATTACH ACCEPT message only if the MS requested "SMS-only service" by including the Additional update type IE in the ATTACH REQUEST message. The MS receiving the ATTACH ACCEPT message takes one of the following actions depending on the GMM cause: # 2 (IMSI unknown in HLR) The MS shall stop timer T3310 if still running and shall reset the routing area updating attempt counter. The MS shall set the update status to U3 ROAMING NOT ALLOWED and shall delete any TMSI, LAI and ciphering key sequence number. The MS shall enter state GMM-REGISTERED.NORMAL-SERVICE. The new MM state is MM IDLE. The SIM/USIM shall be considered as invalid for non-GPRS services until switching off or the SIM/USIM is removed. If the message has been successfully integrity checked by the lower layers and the MS maintains a counter for "SIM/USIM considered invalid for non-GPRS services", then the MS shall set this counter to MS implementation-specific maximum value. # 16 (MSC temporarily not reachable); or # 17 (Network failure) The MS shall stop timer T3310 if still running, and shall enter state MM-IDLE. The routing area updating attempt counter shall be incremented. If the routing area updating attempt counter is less than 5, and the stored RAI is equal to the RAI of the current serving cell and the GMM update status is equal to GU1 UPDATED: - the MS shall keep the GMM update status GU1 UPDATED and changes state to GMM-REGISTERED.ATTEMPTING-TO-UPDATE-MM. The MS shall start timer T3311. When timer T3311 expires the combined routing area update procedure indicating "combined RA/LA updating with IMSI attach" is triggered again. If the routing area updating attempt counter is greater than or equal to 5: - the MS shall start timer T3302 and shall change to state GMM-REGISTERED.ATTEMPTING-TO-UPDATE-MM; - a GPRS MS operating in MS operation mode A shall then proceed with appropriate MM specific procedure; a GPRS MS operating in MS operation mode B may then proceed with appropriate MM specific procedures. The MM sublayer shall act as in network operation mode II as long as the combined GMM procedures are not successful and no new RA is entered. # 22 (Congestion) The MS shall change to state GMM-REGISTERED.ATTEMPTING-TO-UPDATE-MM, shall stop timer T3310 if still running, and shall enter state MM-IDLE. The MS shall set the routing area updating attempt counter to 5 and shall start the timer T3302. # 28 (SMS provided via GPRS in this routing area); The MS shall stop timer T3310 if still running and shall reset the routing area updating attempt counter. The MS shall set the update status to U3 ROAMING NOT ALLOWED and shall delete any TMSI, LAI and ciphering key sequence number. The MS shall enter state GMM-REGISTERED.NORMAL-SERVICE. The new MM state is MM IDLE. The MS stays in the current serving cell and applies the normal cell reselection process. Other GMM causevalues and the case that no GMM cause IE was received are considered as abnormal cases. The combined attach procedure shall be considered as failed for non-GPRS services. The behaviour of the MS in those cases is specified in subclause 4.7.3.2.5.