The present document develops use cases of message communication for MIoT, identifies 5G Message (5GMSG) service potential requirements, and identifies potential requirements on 5G system. The use cases include the following scenarios:

Efficient message communication

Low delay message communication

Group message communication

Multicast and broadcast message communication

High density of UEs message communication

It also provides a gap analysis between the new requirements of message communication for MIoT and the existing operator's message services/3GPP network capabilities, and recommends the future work for the standardization of 5GMSG service for MIoT.

The following documents contain provisions which, through reference in this text, constitute provisions of the present document.

• References are either specific (identified by date of publication, edition number, version number, etc.) or non-specific.
• For a specific reference, subsequent revisions do not apply.
• For a non-specific reference, the latest version applies. In the case of a reference to a 3GPP document (including a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same Release as the present document.

Massive Internet of Things (MIoT) is one of key market segments of 5G. The typical IoT device communication is sending and receiving small data which can be delivered just in a message. Although an IoT application may implement its own message enabler or data communication enabler, it will introduce problems such as interoperability, signalling overhead etc. For the benefit of the IoT ecosystem, it is expected that MNOs provide advanced message service for MIoT. Today SMS is used as message enabler for some IoT applications. However SMS has limitation in term of service capabilities (e.g. 140 bytes payload) and performance (e.g. long latency), in addition, the overhead of control plane resource is high. There have been enhancements and optimizations on the 3GPP network capabilities to facilitate IoT applications including device triggering, small data transfer, Non IP Data Delivery (NIDD), and group messaging etc. Nevertheless, MIoT will bring various new demands on message communication, e.g. light weight message communication for provision and monitoring, ultra low delay and high reliability message communication for remote control, and extremely high resource efficiency for large scale connections. 5GMSG Service is to be developed for this new and huge market segment. It enables an UE sending/receiving message of text, voice, video or data to/from another UE or application server. While SMS is originally designed for person-to-person communication, 5GMSG Service is basically designed for IoT device communication, including thing-to-thing communication and person-to-thing communication. The emerging IoT device communication will introduce new requirements of messaging service in terms of service capabilities, performance, charging, and security etc. The 5GMSG Service enables various messaging communications models including:

• MOMT: UE A sends a message to UE B
• MOAT: UE A sends a message to Application Server
• AOMT: Application Server sends a message to UE A
• MOMT-G: UE A sends a message to a group of UEs
• AOMT-G: Application Server sends a message to a group of UEs
• AOMT-B: Application Server broadcast a message to all UEs ( in a specific service area)

The UEs can be handset and IoT devices. The message communication between two UEs can be with or without a 5GMSG Proxy/Gateway.