School of Specs 23.501v20.2.0

3GPP 23.501 v20.2.0 — the document's own text

5.16.3.8.1 UE originating SMS for IMS Capable UEs supporting SMS over IP

Taught in 21. Emergency calls, messages, voice and location (The 5G system architecture, in depth).

To allow for appropriate domain selection for SMS delivery, it should be possible to provision UEs with the following HPLMN operator preferences on how an IMS enabled UE is supposed to handle SMS services:

    • SMS is not to be invoked over IP networks: the UE does not attempt to deliver SMS over IP networks. The UE attempts to deliver SMS over NAS signalling.
    • SMS is preferred to be invoked over IP networks: the UE attempts to deliver SMS over IP networks. If delivery of SMS over IP networks is not available, the UE attempts to deliver SMS over NAS signalling.