Content for TS 23.554 Word version: 18.2.0

1… 4… 5… 5.5… 6… 7… 8… 8.2… 8.2.3… 8.2.5… 8.3… 8.3.4… 8.4… 8.5… 8.6… 8.7… 8.7.2… 8.7.3… 8.7.4… 8.7.5… 8.8… 8.9… 8.9.3… 8.10… 8.11… 9… 10…

5 Application layer architecture p. 12

5.1 General p. 12

The following aspects of MSGin5G Service are described in this clause:

application architecture;
functional entities;
reference points; and
capability exposure for enabling MSGin5G Service.

5.2 Application Architecture p. 12

Figure 5.2-1 shows the application architecture of the MSGin5G Service. The MSGin5G Service shall fulfil the service requirements which are enumerated in TS 22.262 and the architecture requirements enumerated in clause 4.

Copy of original 3GPP image for 3GPP TS 23.554, Fig. 5.2-1: Application Architecture of the MSGin5G Service

Figure 5.2-1: Application Architecture of the MSGin5G Service
(⇒ copy of original 3GPP image)

The MSGin5G Client(s) interacts with SEAL Clients over the SEAL-C reference point specified for each SEAL service. The Legacy 3GPP Message Gateway and Non-3GPP Message Gateway may interact with SEAL clients over the SEAL-C reference point specified for each SEAL service. The MSGin5G Server(s) interacts with SEAL Servers over the SEAL-S reference point specified for each SEAL service. The interaction between a SEAL Client and the corresponding SEAL Server is supported by SEAL-UU reference point specified for each SEAL service as specified in TS 23.434.

The MSGin5G UE-1 may be constrained devices and unconstrained devices with advanced capabilities, and can communicate with MSGin5G Server over MSGin5G-1 reference point. The MSGin5G UE-2 is a constrained device which does not have enough capability to communicate with MSGin5G Server. If allowed by configuration, the MSGin5G UE-1 may act as a UE Message Gateway to MSGin5G UE-2.

The Legacy 3GPP Message Gateway interacts with MSGin5G Server over MSGin5G-2 reference point on behalf of Legacy 3GPP UE (e.g., SMS, NIDD).

The Non-3GPP Message Gateway interacts with MSGin5G Server over MSGin5G-4 reference point on behalf of Non-3GPP UE.

The Broadcast Message Gateway interacts with MSGin5G Server over MSGin5G-7 reference point.

5.3 Functional entities p. 14

5.3.1 General p. 14

The functional entities of the application architecture for the MSGin5G Service are described in this clause.

5.3.2 MSGin5G Server p. 14

5.3.2.1 General functionalities p. 14

An MSGin5G Server provides server-side functionality to assist MSGin5G Clients with the sending and receiving of messages via the MSGin5G Service to/from Application Servers and/or other MSGin5G Service endpoints on other UEs, and collect charging information from MSGin5G message.

Functionalities of MSGin5G Server:

To resolve message delivery mechanism for the MSGin5G Service endpoint based on the terminating MSGin5G Service ID to determine if the message is to be delivered to an MSGin5G UE, an Application Server or a Message Gateway for final delivery;
To resolve the MSGin5G Group Service ID to determine the members of the Group specified in TS 23.434;
Interworking with non 3GPP messaging service through the Non-3GPP Message Gateway;
Interworking with legacy 3GPP messaging service through the Legacy 3GPP Message Gateway;
Exchanging MSGin5G messages with application servers, MSGin5G Clients, Legacy 3GPP Message Gateway and Non-3GPP Message Gateway;
Supporting MSGin5G message segmentation according to service provider's policy;
Supporting UE configuration procedures as specified in TS 23.434 or communicating with the SEAL Configuration Management Server to provide MSGin5G configuration data on a UE to be ready for the MSGin5G Service;
Managing information related to the MSGin5G Service, such as MSGin5G Client availability, Legacy 3GPP Message Gateway and Non-3GPP Message Gateway; and
Interactions towards the CHF, as defined in TS 32.240, to collect charging information from MSGin5G message according to the operator's charging policy and report charging information to CHF.

5.3.2.2 Target resolution p. 15

Upon receiving the MSGin5G message request to deliver the message to the recipient (which could be any of the MSGin5G UE, Legacy 3GPP UE, Non-3GPP UE or Application Server) on the terminating side, the MSGin5G Server checks the recipient's registration repository (created at the time of each MSGin5G UE/Application Server registration to MSGin5G Server, or the Message Gateway performs registration with the MSGin5G Server on behalf of the Non-MSGin5G UEs) for the Identities of MSGin5G service endpoints, i.e. UE Service ID/AS Service ID. The MSGin5G Server will attempt for delivery MSGin5G message request towards recipient based on the UE Service ID/AS Service ID. If the recipient is Non-MSGin5G UE, the Message Gateway that the Non-MSGin5G UE is registered with will receive the MSGin5G message request on behalf of the Non-MSGin5G UE, and then delivers the message to the Non-MSGin5G UE by using the Non-MSGin5G message delivery mechanism.

5.3.3 MSGin5G Client p. 15

An MSGin5G Client provides client-side functionality for UE Application Clients with the sending and receiving of messages via the MSGin5G Service to/from Application Servers and/or other MSGin5G Service endpoints; i.e. UEs.

Functionalities of MSGin5G Client including:

may expose MSGin5G APIs to enable Application Clients to use an MSGin5G Service;
supporting registration of an MSGin5G Client to an MSGin5G Server to use MSGin5G Service;
supporting configuration of an MSGin5G Client required to use MSGin5G Service;
construction of MSGin5G message when requested by a native application or Application Client;
delivery of MSGin5G message payload to the targeted native application or Application Client; and
exchanging MSGin5G messages via an MSGin5G Server to/from Application Servers and/or other MSGin5G Service endpoints; i.e. UEs. and
acting as a relay for MSGin5G Client resides in other UE, which does not have enough capability to communicate with MSGin5G Server (i.e. a constrained device), to use MSGin5G Service.

5.3.4 Message Gateway p. 16

5.3.4.1 General Description of Message Gateway p. 16

A Message Gateway in MSGin5G application architecture provides functionality to deliver MSGin5G messages to Non-MSGin5G UEs.

A Message Gateway performs the role of interconnecting two different messaging delivery mechanisms and assures the message integrity between different message delivery mechanisms. A message delivery mechanism comprises the specific set of protocols, procedures and rules.

Functionalities of Message Gateway:

Enables seamless delivery of an MSGin5G message between different message delivery mechanisms with integrity;
Communicates with the MSGin5G Server using either an MSGin5G Client functionality or similar functions to enable sending and receiving MSGin5G messages;
Delivers payload of an MSGin5G message to the Non-MSGin5G UE using the specific message delivery mechanism available to that Non-MSGin5G UE and vice versa;
Performs message sender and receiver addresses conversion according to the two connected message delivery mechanisms and maintain the mapping of the address pair used for a response message delivery;
Perform registration and de-registration with the MSGin5G Server on behalf of the Non-MSGin5G UEs;
Act as a service endpoint to perform message segmentation and reassembly for the Non-MSGin5G UEs when needed; and
Performs protocol conversion according to the service supported by the target UE;
Supports the MSGin5G message delivery status report
1. If application level message delivery status report is not supported by the Non-MSGin5G message delivery mechanisms, based on the information (e.g. response to the message delivery request, transport level information, etc) obtained from the Non-MSGin5G message delivery mechanisms, the Message Gateway fetches the delivery status from the above information and uses it to create an MSGin5G message delivery status report on behalf of Non-MSGin5G UE. If the delivery status is failure, also fetch the suitable failure reason from the above information and use it as reason of failure in the MSGin5G message delivery status report.
2. If application level message delivery status report is supported by the Non-MSGin5G message delivery mechanisms (e.g. RCS specified in GSMA PRD RCC.07 [3]), translates the application level message delivery status report in the Non-MSGin5G message delivery mechanisms to MSGin5G message delivery status report.

There are two types of Message Gateways used to deliver MSGin5G messages to different UE types: the Legacy 3GPP Message Gateway and the non-3GPP Message Gateway

5.3.4.2 Legacy 3GPP Message Gateway p. 16

The Legacy 3GPP Message Gateway is used to deliver MSGin5G message to Legacy 3GPP UEs, using their 3GPP supported message delivery mechanisms.

5.3.4.3 Non-3GPP Message Gateway p. 17

The Non-3GPP Message Gateway is used to deliver MSGin5G message to Non-MSGin5G UEs, using their (non-3GPP) supported message delivery mechanisms.

5.3.4.4 Broadcast Message Gateway |R18| p. 17

The Broadcast Message Gateway is used to deliver MSGin5G message to MSGin5G UEs, Legacy 3GPP UEs or Non-MSGin5G UEs in a Broadcast Area.

5.3.5 Application Client p. 17

The Application Client is an entity in the application layer to implement and perform the application service logic for its own service.

The Application Client interacts with MSGin5G Client for sending and receiving MSGin5G messages. The Application Client provides needed information for the MSGin5G Client to perform MSGin5G Service with other endpoints.

5.3.6 Application Server p. 17

The Application Server is an entity in the application layer to implement and perform the application service logic.

The Application Server supports sending and receiving messages with MSGin5G Service layer protocols and procedures.

5.3.7 Legacy 3GPP Message Client p. 17

The Legacy 3GPP Message Client provides client-side functionality for a Legacy 3GPP messaging service (e.g. SMS, NIDD).

5.3.8 Non-3GPP Message Client p. 17

The Non-3GPP Message Client provides client-side functionality for a Non-3GPP messaging service.

5.3.9 SEAL Client p. 17

The following SEAL Clients for MSGin5G Service are supported:

Group management client as specified in TS 23.434;
Configuration management client as specified in TS 23.434.

5.3.10 SEAL server p. 17

The following SEAL servers for MSGin5G Service are supported:

Group management server as specified in TS 23.434;
Configuration management server as specified in TS 23.434.

5.4 Reference Points p. 18

5.4.1 General p. 18

The reference points of the service architecture for the MSGin5G Service are described in this clause.

5.4.2 MSGin5G-1 p. 18

The interactions related to enabling MSGin5G message exchange between an MSGin5G Client and an MSGin5G Server are supported by the MSGin5G-1 reference point. This reference point supports:

Registration of an MSGin5G Client to an MSGin5G Server when not using IMS based solution; and
The exchange of MSGin5G messages.

5.4.3 MSGin5G-2 p. 18

The interactions related to enabling MSGin5G message exchange between an MSGin5G Server and the Legacy 3GPP Message Gateway are supported by the MSGin5G-2 reference point. This reference point supports:

The exchange of MSGin5G messages between MSGin5G Server and the Legacy 3GPP Message Gateway; and
Perform registration /de-registration on behalf of the Legacy 3GPP UEs that the Message Gateway connects with the MSGin5G Server.

5.4.4 MSGin5G-3 p. 18

The interactions related to enabling MSGin5G message exchange between an Application Server and an MSGin5G Server are supported by the MSGin5G-3 reference point. This reference point supports:

Access to MSGin5G Server and APIs to enable sending and receiving of MSGin5G messages; and
Adherence to CAPIF as specified in TS 23.222.

5.4.5 MSGin5G-4 p. 18

The interactions related to enabling MSGin5G message exchange between a Non-3GPP Message Gateway and an MSGin5G Server are supported by the MSGin5G-4 reference point. This reference point supports:

The exchange of MSGin5G messages between MSGin5G Server and the Non-3GPP Message Gateway; and
Perform registration/de-registration on behalf of the Non-3GPP UEs that the Message Gateway connects with the MSGin5G Server

5.4.6 MSGin5G-5 p. 18

The interactions related to enabling MSGin5G message related information exchange between an Application Client and an MSGin5G Client are supported by the MSGin5G-5 reference point. This reference point supports:

Providing information from Application Clients required to enable the MSGin5G Client to construct an MSGin5G message to be delivered to other MSGin5G Service endpoints.
Configuring application clients with information required to enable the MSGin5G Client and MSGin5G Server to exchange and route MSGin5G messages to other MSGin5G Service endpoints.
Sending notifications and information in the incoming MSGin5G messages received by the MSGin5G Client to the Application Clients from other MSGin5G Service endpoints.

5.4.7 MSGin5G-6 p. 19

The MSGin5G Client of MSGin5G UE-2 communicates with MSGin5G Client of MSGin5G UE-1 over MSGin5G-6 reference point. The interface is based on NR PC5.

5.4.8 SEAL-C p. 19

The following SEAL-C reference points for MSGin5G Service are supported:

GM-C reference point for group management as specified in TS 23.434;
CM-C reference point for configuration management as specified in TS 23.434.

5.4.9 SEAL-S p. 19

The following SEAL-S reference points for MSGin5G Service are supported:

GM-S reference point for group management as specified in TS 23.434;
CM-S reference point for configuration management as specified in TS 23.434.

5.4.10 SEAL-UU p. 19

The following SEAL-UU reference points for MSGin5G Service are supported:

GM-UU reference point for group management as specified in TS 23.434;
CM-UU reference point for configuration management as specified in TS 23.434.

5.4.11 MSGin5G-7 |R18| p. 19

The MSGin5G-7 reference point is used by the MSGin5G Server to communicate with the Broadcast Message Gateway to deliver Broadcast messages.