Showing posts with label NAS. Show all posts
Showing posts with label NAS. Show all posts

Thursday, October 1, 2015

Friday, September 25, 2015

NAS Procedure

1. NAS Prcodeure?
A. According 24.301 (NAS) There are two types of procedure which can be seen on NAS layer.

      EMM (EPS Mobility Management) Procedure.     Three types of ESM procedures can be distinguished.
  1.  EMM common procedures:
     An EMM common procedure can always be initiated whilst a NAS signalling connection exists.

    The procedures belonging to this type are:
                              Initiated by the NW: -
                                           GUTI reallocation; -
                                           Authentication; -
                                           Security mode control; -
                                           Identification; -
                                           EMM information. 
  2. EMM specific procedures:
    At any time only one UE initiated EMM specific procedure can be running.
    The procedures belonging to this type are:
                              Initiated by the UE:
                                            Attach: -
                                            Detach:-
                                            Tracking Area Update:-
                                                         Normal and periodic tracking area updating procedure
                                                         Combined tracking area updating procedure
                              Initiated by the NW:
                                            Detach:- 
  3. EMM connection management procedures (S1 mode only):
                              Initiated by the UE: -
                                           Service request
                              Initiated by the UE/NW: -
                                           Transport of NAS Messages
                                           Generic transport of NAS messages procedure

                                Note:  Not sure why two different kind of transport of NAS messages?
                                           Need to check in detail about their work and differences and need.

                              Initiated by the NW: -
                                           Paging Procedure