5.2.3.2.5 UPDATE-NEEDED ....................................................................................................................................... 67
5.2.3.2.6 NO-CELL-AVAILABLE.............................................................................................................................. 67
5.2.3.2.7 ATTEMPTING-TO-UPDATE-MM ........................................................................................................... 67
5.2.3.2.8 IMSI-DETACH-INITIATED ....................................................................................................................... 67
5.3 General on elementary EMM procedures ..................................................................................................................... 68
5.3.1 EMM modes and NAS signalling connection ........................................................................................................ 68
5.3.1.1 Establishment of the NAS signalling connection............................................................................................ 68
5.3.1.2 Release of the NAS signalling connection ....................................................................................................... 69
5.3.1.2.1 General.............................................................................................................................................................. 69
5.3.1.2.2 UE is using EPS services with control plane CIoT EPS optimization .................................................. 71
5.3.1.3 Suspend and resume of the NAS signalling connection ................................................................................ 71
5.3.2 Lists of forbidden tracking areas .............................................................................................................................. 72
5.3.3 List of forbidden PLMNs for attach in S101 mode............................................................................................... 73
5.3.3a Forbidden PLMNs for EPS services ........................................................................................................................ 73
5.3.4 Equivalent PLMNs list ............................................................................................................................................... 73
5.3.5 Handling of the periodic tracking area update timer and mobile reachable timer (S1 mode only) .............. 73
5.3.6 Handling of timer T3402 ........................................................................................................................................... 75
5.3.7 Handling of the Local Emergency Numbers List .................................................................................................. 75
5.3.7a Specific requirements for UE configured to use timer T3245............................................................................. 76
5.3.7b Specific requirements for UE when receiving non-integrity protected reject messages ................................ 76
5.3.8 Abnormal cases in the UE ......................................................................................................................................... 78
5.3.9 Handling of NAS level mobility management congestion control..................................................................... 79
5.3.9A Handling of congestion control for transport of user data via the control plane .............................................. 80
5.3.10 Access class control .................................................................................................................................................... 80
5.3.11 Power saving mode ..................................................................................................................................................... 80
5.3.12 Extended idle-mode DRX cycle ............................................................................................................................... 81
5.3.13 Interaction between power saving mode and extended idle mode DRX cycle ................................................ 82
5.3.14 Dedicated core network.............................................................................................................................................. 82
5.3.15 CIoT EPS optimizations............................................................................................................................................. 82
5.3.16 Restriction on use of enhanced coverage ................................................................................................................ 84
5.4 EMM common procedures .............................................................................................................................................. 84
5.4.1 GUTI reallocation procedure .................................................................................................................................... 84
5.4.1.1 General.................................................................................................................................................................... 84
5.4.1.2 GUTI reallocation initiation by the network .................................................................................................... 84
5.4.1.3 GUTI reallocation completion by the UE......................................................................................................... 85
5.4.1.4 GUTI reallocation completion by the network ................................................................................................ 85
5.4.1.5 Abnormal cases in the UE ................................................................................................................................... 85
5.4.1.6 Abnormal cases on the network side ................................................................................................................. 85
5.4.2 Authentication procedure........................................................................................................................................... 87
5.4.2.1 General.................................................................................................................................................................... 87
5.4.2.2 Authentication initiation by the network .......................................................................................................... 87
5.4.2.3 Authentication response by the UE ................................................................................................................... 87
5.4.2.4 Authentication completion by the network ...................................................................................................... 88
5.4.2.5 Authentication not accepted by the network .................................................................................................... 89
5.4.2.6 Authentication not accepted by the UE............................................................................................................. 89
5.4.2.7 Abnormal cases ..................................................................................................................................................... 90
5.4.3 Security mode control procedure.............................................................................................................................. 94
5.4.3.1 General.................................................................................................................................................................... 94
5.4.3.2 NAS security mode control initiation by the network .................................................................................... 95
5.4.3.3 NAS security mode command accepted by the UE ........................................................................................ 97
5.4.3.4 NAS security mode control completion by the network ................................................................................ 98
5.4.3.5 NAS security mode command not accepted by the UE ................................................................................. 98
5.4.3.6 Abnormal cases in the UE ................................................................................................................................... 98
5.4.3.7 Abnormal cases on the network side ................................................................................................................. 99
5.4.4 Identification procedure ............................................................................................................................................. 99
5.4.4.1 General.................................................................................................................................................................... 99
5.4.4.2 Identification initiation by the network........................................................................................................... 100
5.4.4.3 Identification response by the UE .................................................................................................................... 100
5.4.4.4 Identification completion by the network....................................................................................................... 100
