ForewordIntroduction1 Scope2 References3 Definitions, symbols and abbreviations4 Architectural requirements5 Application layer architecture6 Identities7 Generic description of the MSGin5G Service (informative)8 Procedures and information flows8.1 Configuration8.2 Registration8.2.1 MSGin5G UE Registration8.2.2 MSGin5G UE De-Registration8.2.3 Non-MSGin5G UE Registration8.2.4 Non-MSGin5G UE De-registration8.2.7 MSGin5G UE bulk registration over MSGin5G-6 reference point8.2.8 Constrained device selecting MSGin5G Relay UE or MSGin5G Proxy UE8.2.9 Non-MSGin5G UE bulk de-registration8.2.10 Non-MSGin5G UE bulk de-registration8.3 Message delivery procedures into and from MSGin5G Server8.4 Message Aggregation8.5 MSGin5G Message Segmentation and Reassembly8.6 MSGin5G messaging procedure on Message Gateway8.7 E2E Message delivery procedures8.7 E2E Message delivery procedures8.7.1 Point-to-Point Message delivery procedures8.7.2 Application-to-Point Message delivery procedures8.7.3 Point-to-Application Message delivery procedures8.7.4 MSGin5G Group messaging8.7.5 Message delivery between different PLMNs8.7.6 Broadcast message delivery8.8 Other MSGin5G messaging related procedures8.11 Constrained devices in MSGin5G Service9 APIs and related information flows10 Information Elements Introduction 23.5543GPPApplication architecture for MSGin5G ServiceRelease 18Stage 2TS Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM