4 xMB reference point

29.1163GPPRelease 18Representational state transfer over xMB reference point between content provider and BM-SCTS

4.1 Overview

4.2 Reference model

The xMB reference point resides between the BM-SC and the Content Provider as depicted in Figure 4.2.1. Control- and user-plane procedures are operated over the xMB-C and xMB-U reference points, respectively. The overall xMB reference model is depicted in clause 4.1 of 3GPP TS 26.348 [33].

Figure 4.2.1 xMB reference point

For the V2X Localized User Plane supported feature, the reference model in Annex B.3 of 3GPP TS 23.285 [23] applies.

4.3 Functional elements

4.3.1 BM-SC

The complete functionality of the BM-SC is defined in 3GPP TS 26.346 [3]. In the context of the xMB reference point, the BM-SC represents the peer endpoint to the Content Provider in supporting all procedures on the xMB interface.

In addition to the functions defined in 3GPP TS 26.346 [3], the BM-SC may support, for V2X services, the V2X Localized User Plane procedures as defined in 3GPP TS 23.285 [23] clause 5.4.2.2 for receiving Local MBMS information from the Content Provider acting as a V2X Application Server.

4.3.2 Content Provider / Multicast Broadcast Source

The functional role of the Content Provider is defined in clause 4.4.1a of 3GPP TS 26.346 [3]. Using the xMB reference point, a Content Provider/Multicast Broadcast Source may provide media, as well as service descriptions and control data, to the BM-SC to set up and manage MBMS User Service(s) from the BM-SC to MBMS clients (the latter is not depicted in Figure 4.2.1).

In addition, the Content Provider which acts as a V2X Application Server may support V2X Localized User Plane procedures as defined in 3GPP TS 23.285 [23] clause 5.4.2.2 for requesting the BM-SC to activate an MBMS bearer for Local MBMS based MBMS data delivery.

The content provider may also be a mission critical service provider (3GPP TS 23.280 [36]) which is arranging MC Services to Mission Critical Organizations and may require additional control of the resource allocation (QoS, coverage area).

The Content Provider may be a 5GMS Application Provider as defined in clause 4.1 of TS 26.348 [33], providing 5G Media Streaming services to a 5GMS System.

4.4 Procedures over xMB reference point

4.4.1 Introduction

All procedures that operate across the xMB reference point, as specified in clause 5 of 3GPP TS 26.348 [33], are summarized in the following clauses.

4.4.2 Authentication Procedures

Authentication procedures shall be performed via (D)TLS as specified by 3GPP TS 33.246 [24]. The Content Provider shall act as the (D)TLS client and the BM-SC as the (D)TLS server when the Content Provider wants to provision new services or manage existing services. Similarly, the BM-SC shall act as the client when the BM-SC wishes to send reports and notifications to the Content Provider. All of the following procedures require the authentication procedure to be completed successfully.

4.4.3 Authorization Procedures

The authorization procedure of the Content Provider towards the BM-SC may be based on the (D)TLS connection established as part of the authentication procedure (see clause 4.4.2). In that case, the BM-SC shall check if the Content Provider who sent a request over an authenticated (D)TLS connection is authorized to send that specific request. See clause 7.2 for further details.

The authorization procedure of the BM-SC towards the Content Provider to allow pushing notifications to the Content Provider may be based on the (D)TLS connection established as part of the authentication procedure (see clause 4.4.2). In that case, the Content Provider shall check if the BM-SC who sent the notification over an authenticated (See clause 7.2 for further details)(D)TLS connection is authorized to send that specific notification.

4.4.4 Service Management Procedures

4.4.4.1 Create Service

This procedure is used by the Content Provider to create a service at the BM-SC and negotiate the supported features for the created service. The Content Provider shall use HTTP POST for this purpose. A successfully created service is associated with a resource identifier which is used by the Content Provider to discover, update and delete the service.

4.4.4.2 Get Service Properties

This procedure is used by the Content Provider to obtain the service properties from the BM-SC. The Content Provider shall use HTTP GET for this purpose.

4.4.4.3 Update Service Properties

This procedure is used by the Content Provider for updating the service properties at the BM-SC. The Content Provider shall use HTTP PUT or HTTP PATCH, corresponding to complete or partial update of service properties, respectively, for this purpose.

4.4.4.4 Delete Service

This procedure is used by the Content Provider to terminate the service at the BM-SC. The Content Provider shall use HTTP DELETE for this purpose.

4.4.4.5 Service Notifications

This procedure is used by the BM-SC to send service related notifications to the Content Provider.

4.4.5 Session Management Procedures

4.4.5.1 Create Session

This procedure is used by the Content Provider to create a session for a previously created service at the BM-SC. The Content Provider shall use HTTP POST for this purpose. A successfully created session is associated with a resource identifier which is used by the Content Provider to discover, update and delete the session.

4.4.5.2 Get Session Properties

This procedure is used by the Content Provider to obtain the session properties of a service from the BM-SC. The Content Provider shall use HTTP GET for this purpose.

4.4.5.3 Update Session Properties

This procedure is used by the Content Provider for updating the session properties of a session at the BM-SC. The Content Provider shall use HTTP PUT or HTTP PATCH, corresponding to complete or partial update of session properties, respectively, for this purpose.

If the V2X Localized User Plane feature is supported, the Content Provider may wish to update the session properties for Local MBMS based MBMS data delivery. If so, and the BM-SC decides to use the Local MBMS information, the BM-SC shall use the received BM-SC IP address and port for user plane data delivery.

NOTE: The Local MBMS information is pre-configured in the Content Provider. At reception of such information, the BM-SC will further send the M1 interface information (e.g. MBMS eNB multicast address and GW source specific multicast address) to the MBMS-GW as specified in 3GPP TS 29.061 [20].

If the MCExtension feature is supported, the content provider acting as a mission critical service provider may include:

– additional properties for resource allocation control (mc-extension in table 5.2.2.1-1); and

– specific semantic and syntax for the geographical area (clause 5.4.7 of 3GPP TS 26.348 [33]).

4.4.5.4 Delete Session

This procedure is used by the Content Provider to terminate a session of a service at the BM-SC. The Content Provider shall use HTTP DELETE for this purpose.