TS24.501-g40 4.20 5GS session management in WB-N1 mode for IoT

4.20 5GS session management in WB-N1 mode for IoT

In WB-N1 mode, a UE operating in category CE can operate in either CE mode A or CE mode B (see 3GPP TS 36.306 [25D]). If a UE that supports CE mode B and operates in WB-N1 mode and the UE's usage setting is not set to "voice centric" (see 3GPP TS 23.501 [8]), the UE shall apply the value of the applicable NAS timer indicated in table 10.3.1 for WB-N1/CE mode.

The NAS 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 be re-calculated until the NAS procedure is completed, restarted or aborted.

The use of CE mode B by a UE is indicated to the SMF by the AMF. The SMF shall calculate the value of the applicable NAS timer indicated in table 10.3.2 for WB-N1/CE mode.

The NAS 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 be re-calculated until the NAS procedure is completed, restarted or aborted.