4.18 5GS session management in NB-N1 mode

24.5013GPPNon-Access-Stratum (NAS) protocol for 5G System (5GS)Release 17Stage 3TS

A UE in NB-N1 mode (see 3GPP TS 36.331 [25A]) shall calculate the value of the applicable NAS timer indicated in table 10.3.1 plus 180s.

The timer value obtained is used as described in the appropriate procedure subclause of this specification. The NAS timer value shall be calculated at start of a NAS procedure and shall not re-calculate the use of the NAS timer value until the NAS procedure is completed, restarted or aborted.

When an SMF that supports NB-N1 mode performs NAS signalling with a UE, which is using NB-N1 mode, the SMF shall calculate the value of the applicable NAS timer indicated in table 10.3.2 plus 180s.

The timer value obtained is used as described in the appropriate procedure subclause of this specification. The NAS timer value shall be calculated at start of a NAS procedure and shall not re-calculate the use of the NAS timer value until the NAS procedure is completed, restarted or aborted.