Section: 4.5.1.6.1 Call re-establishment, initiation by the mobile station
Content: NOTE: The network is unable to initiate call re-establishment. If at least one request to re-establish an MM connection is received from a CM entity as a response to the indication that the MM connection is interrupted (see subclause 4.5.2.3.) the mobile station initiates the call re-establishment procedure. If several CM entities request re-establishment only one re-establishment procedure is initiated. If any CM entity requests re-establishment, then re-establishment of all transactions belonging to all Protocol Discriminators that permit Call Re-establishment shall be attempted. Upon request of a CM entity to re-establish an MM connection the MM sublayer requests the RR sublayer to establish an RR connection and enters MM sublayer state WAIT FOR REESTABLISH. This request contains an establishment cause and a CM RE-ESTABLISHMENT REQUEST message. When the establishment of an RR connection is indicated by the RR sublayer, the MM sublayer of the mobile station starts timer T3230, gives an indication to all CM entities that are being re-established, and remains in the MM sublayer state WAIT FOR REESTABLISH. The CM RE-ESTABLISHMENT REQUEST message contains the - mobile identity according to subclause 10.5.1.4; - mobile station classmark 2; - ciphering key sequence number. NOTE: Whether or not a CM entity can request re-establishment depends upon the Protocol Discriminator. The specifications for Short Message Service (3GPP TS 24.011[ Point-to-Point  (PP) Short Message Service (SMS) support on mobile radio interface ]  [22]), Call Independent Supplementary Services (3GPP TS 24.010[ Mobile radio interface  layer 3; Supplementary services specification; General aspects ]  [21]) and Location Services (3GPP TS 44.071[ None ]  [23a]) do not currently specify any re-establishment procedures. For a shared GERAN in A/Gb mode, if the MS is a GERAN network sharing supporting MS, the chosen PLMN identity shall be indicated to the GERAN in the CM RE-ESTABLISHMENT REQUEST message using the Skip Indicator IE as specified in subclause 10.3.1. Upon receiving a CM RE-ESTABLISHMENT REQUEST message, the network shall analyse its content. Depending on the type of request, the network may start any of the MM common procedures and RR procedures. The network may initiate the classmark interrogation procedure, for example, to obtain further information on the mobile station's encryption capabilities. The identification procedure (see subclause 4.3.3) may be invoked. The network may invoke the authentication procedure (see subclause 4.3.2). In A/Gb mode, the network decides if the security mode setting procedure shall be invoked (see 3GPP TS 44.018[ None ]  [84] subclause 3.4.7). An indication from the RR sublayer that the security mode setting procedure is completed, or reception of a CM SERVICE ACCEPT message, shall be treated as a service acceptance indication by the mobile station. In Iu mode, the network decides if the security mode control procedure shall be invoked (see 3GPP TS 25.331[ None ]  [23c] and 3GPP TS 44.118[ None ]  [111]). An indication from the RR sublayer that the security mode control procedure is completed, or reception of a CM SERVICE ACCEPT message, shall be treated as a service acceptance indication by the mobile station. The MM connection re-establishment is completed, timer T3230 shall be stopped, all CM entities associated with the re-establishment shall be informed, and MM sublayer state MM CONNECTION ACTIVE is re-entered. All the MM connections are considered to be active. If the network cannot associate the re-establishment request with any existing call for that mobile station, a CM SERVICE REJECT message is returned with the reject cause: #38 "call cannot be identified" If call re-establishment cannot be performed for other reasons, a CM SERVICE REJECT is returned, the appropriate reject cause may be any of the following (see annex G): # 4 "IMSI unknown in VLR"; # 6 "illegal ME"; #17 "network failure"; #22 "congestion"; #25 "not authorized for this CSG"; #32 "service option not supported"; #34 "service option temporarily out of order". If the service request is rejected due to general NAS level mobility management congestion control, the network shall set the MM cause value to #22 "congestion" and assign a back-off timer T3246 (see 3GPP TS 23.012[ Location management procedures ]  [140]). Whatever the reject cause a mobile station receiving a CM SERVICE REJECT as a response to the CM RE-ESTABLISHMENT REQUEST shall stop T3230, release all MM connections and proceed as described in subclause 4.5.3.1. In addition: - if cause value #4 is received, the mobile station deletes any TMSI, LAI and ciphering key sequence number in the SIM/USIM, changes the update status to NOT UPDATED (and stores it in the SIM/USIM according to subclause 4.1.2.2), and enters the MM sublayer state WAIT FOR NETWORK COMMAND. If subsequently the RR connection is released or aborted, this will force the mobile station to initiate a normal location updating. The CM re-establishment request shall not be memorized during the location updating procedure. - if cause value #6 is received, the mobile station deletes any TMSI, LAI and ciphering key sequence number in the SIM/USIM, changes the update status to ROAMING NOT ALLOWED (and stores it in the SIM/USIM according to subclause 4.1.2.2), and enters the MM sublayer state WAIT FOR NETWORK COMMAND. The MS shall consider the SIM/USIM as invalid for non-GPRS services until switch-off or the SIM/USIM is removed. - If cause value # 22 is received, the T3246 value IE is present in the CM SERVICE REJECT message and the value indicates that this timer is neither zero nor deactivated, the MS shall abort the re-establishment, release any MM connections, and proceed as specified in subclause 4.5.3.1. The MS shall stop timer T3246 if it is running. If the CM SERVICE REJECT message is integrity protected, the MS shall start timer T3246 with the value provided in the T3246 value IE. If the CM SERVICE REJECT message is not integrity protected, the MS shall start timer T3246 with a random value from the default range specified in table 11.1. The MS stays in the current serving cell and applies the normal cell reselection process. The CM RE-ESTABLISHMENT REQUEST procedure should not be restarted when timer T3246 expires or is stopped. If cause value #22 is received, the T3246 value IE is not present in the CM SERVICE REJECT message or if the value provided in the T3246 value IE indicates that this timer is zero or deactivated, the MS shall abort the re-establishment, release any MM connections, and proceed as specified in subclause 4.5.3.1. - if cause value #25 is received from a CSG cell and the mobile station is in UTRAN Iu mode, the MS shall check whether the CM SERVICE REJECT message with cause #25 is integrity protected. If the message is not integrity protected, the MS shall discard the message. Otherwise, the MS shall remove the entry corresponding to the CSG ID and associated PLMN identity of the cell where the MS has sent the CM SERVICE REQUEST message from the Allowed CSG list if the CSG ID and associated PLMN identity are contained in the Allowed CSG list, and enter the MM sublayer state WAIT FOR NETWORK COMMAND. If the CSG ID and associated PLMN identity of the cell where the MS has sent the CM SERVICE REQUEST message is contained in the Operator CSG list, the MS shall proceed as specified in 3GPP TS 23.122[ Non-Access-Stratum (NAS) functions related to Mobile Station (MS) in idle mode ]  [14] subclause 3.1A. If cause value #25 is received and the cell is not a CSG cell or the MS is not in UTRAN Iu mode, the MS shall discard the CM SERVICE REJECT message.