Section: 5.4.4.5 Abnormal cases in the UE
Content: The following abnormal cases can be identified: a) Requested identity is not available If the UE cannot encode the requested identity in the IDENTITY RESPONSE message, e.g. because no valid USIM is available, then it shall encode the identity type as "no identity". b) Transmission failure of IDENTITY RESPONSE message indication from lower layers (if the identification procedure is triggered by a tracking area updating procedure or an attach procedure) The UE shall abort the identification procedure and re-initiate the tracking area updating procedure if the identification procedure is triggered by a tracking area updating procedure. The UE shall abort the identification procedure and re-initiate the attach procedure if the identification procedure is triggered by an attach procedure. c) Transmission failure of IDENTITY RESPONSE message indication with TAI change from lower layers (if the identification procedure is triggered by a service request procedure) If the current TAI is not in the TAI list, the identification procedure shall be aborted and a tracking area updating procedure shall be initiated. If the current TAI is still part of the TAI list, the identification procedure shall be aborted and it is up to the UE implementation how to re-run the ongoing procedure that triggered the identification procedure. d) Transmission failure of IDENTITY RESPONSE message indication without TAI change from lower layers (if the identification procedure is triggered by a service request procedure) The identification procedure shall be aborted and it is up to the UE implementation how to re-run the ongoing procedure that triggered the identification procedure.