scope:

The present document specifies the protocol aspects for supporting MSGin5G services as specified in 3GPP TS 23.554 [2] for:

1. communication between the MSGin5G UE and the MSGin5G Server over the MSGin5G-1 interface;

2. communication between the Constrained UE (without MSGin5G Client) and MSGin5G Gateway UE which is an Unconstrained UE over the MSGin5G-5 interfaces; and

3. communication between the Constrained UE (with MSGin5G Client) and the MSGin5G Relay UE which is an Unconstrained UE over the MSGin5G-6 interfaces.

The present specification defines the usage and interactions of the MSGin5G Service with SEAL services.

The present specification also defines the message format, message contents, error handling and system parameters applied by the protocols for the MSGin5G Service.