Hi Dheernedra,
There are number of reject cause is available . please read 24.501-5.5.1.2.5
3 (Illegal UE); or #6 (Illegal ME).
consider the USIM as invalid for 5GS services until switching off or the UICC containing the USIM is removed
delete the list of equivalent PLMNs and enter the state 5GMM-DEREGISTERED.
7 (5GS services not allowed)
consider the USIM as invalid for 5GS services until switching off or the UICC containing the USIM is removed
delete the list of equivalent PLMNs and enter the state 5GMM-DEREGISTERED.
11 (PLMN not allowed)
delete the list of equivalent PLMNs and reset the registration attempt counter and store the PLMN identity in the "forbidden PLMN list".
enter state 5GMM-DEREGISTERED.PLMN-SEARCH and perform a PLMN selection
12 (Tracking area not allowed)
shall delete 5G-GUTI, last visited registered TAI, TAI list and ngKSI.
reset the registration attempt counter
store the current TAI in the list of "5GS forbidden tracking areas for regional provision of service" and enter the state 5GMM-DEREGISTERED.LIMITED-SERVICE.
13 (Roaming not allowed in this tracking area).
delete 5G-GUTI, last visited registered TAI, TAI list and ngKSI. Additionally, the UE shall delete the list of equivalent PLMNs
reset the registration attempt counter.
store the current TAI in the list of "5GS forbidden tracking areas for roaming" and enter the state 5GMM-DEREGISTERED.LIMITED-SERVICE or optionally 5GMM-DEREGISTERED.PLMN-SEARCH
15 (No suitable cells in tracking area)
store the current TAI in the list of "5GS forbidden tracking areas for roaming" and enter the state 5GMM-DEREGISTERED.LIMITED-SERVICE.
search for a suitable cell in another tracking area
22 (Congestion)
If the T3346 value IE is present in the REGISTRATION REJECT message and the value indicates that this timer is neither zero nor deactivated,
abort the initial registration procedure, set the 5GS update status to 5U2 NOT UPDATED and enter state 5GMM-DEREGISTERED.ATTEMPTING-REGISTRATION.
stop timer T3346 if it is running
stays in the current serving cell and applies the normal cell reselection process. The initial registration procedure is started if still needed when timer T3346 expires or is stopped.
Else
consider it as abnorma case
27 (N1 mode not allowed)
delete any 5G-GUTI, last visited registered TAI, TAI list and ngKSI.
reset the registration attempt counter and shall enter the state 5GMM-NULL.
disable the N1 mode capability for both 3GPP access and non-3GPP access.
72 (Non-3GPP access to 5GCN not allowed)
delete 5G-GUTI, last visited registered TAI, TAI list and ngKSI
reset the registration attempt counter and enter the state 5GMM-DEREGISTERED.
73 (Serving network not authorized)
reset the registration attempt counter
store the PLMN identity in the "forbidden PLMN list"
enter state 5GMM-DEREGISTERED.PLMN-SEARCH
