A.5 HLS Media Presentation Delivery
26.3483GPPNorthbound Application Programming Interface (API) for Multimedia Broadcast/Multicast Service (MBMS) at the xMB reference pointRelease 17TS
A.5.1 Introduction
This subclause illustrates the xMB-U constraints and options for HLS delivery.
An HLS presentation typically consists of a single Master Playlist and multiple Media Playlists, one for each media Rendition. Media Playlists specify a sequence of media segments, each containing media data. A Media Playlist may also specify, by way of an EXT-MAP tag, a segment containing only the subsequent sequences’ CMAF Header. These header-only segments are also referred to as Initialization Segments (IS) or Media Initialization Sections.
A.5.2 Segment and Playlist Order Guarantee
As mentioned in subclause 5.5.2, media segments should be made available to the BM-SC, and ingested using xMB-U, prior to the ingestion of the Media Playlists that specify those segments. This ordering is the responsibility of the Content Provider, irrespective of ingest mode, as detailed below.
A.5.3 HLS Content Ingestion with Pull
A.5.3.1 Introduction
The Content Provider delegates all MBMS related complexity to the operator and provides HLS compliant content using an HTTP GET method to the BM-SC. The Content Provider is responsible for ensuring the required ordering of media segments and Media Playlist availability to the requesting BM-SC. Using the Pull ingest mode the BM-SC should parse the supplied Media Playlist, at each update, to discover new media segment URIs.
The following Session Properties allow the configuration of this xMB-U mode.
– Session Type is set by the Content Provider to Application.
– Ingest Mode (Session Type specific property) is set by the Content Provider to Pull.
– Application Service Description (Session Type specific property) is set to application/vnd.apple.mpegurl.
– Application Entry Point URL contains the URL to the HLS Master Playlist. The BM-SC will fetch the Master Playlist using the value of the Application Entry Point URL and embed the Master Playlist into the Service Announcement File (via SACH).
A.5.3.2 Content ingestion steps
1: The Content Provider creates the HLS Delivery Service and Session using xMB procedures.
2: As a result of the Service and Session provisioning procedure, the Content Provider gets the service identification information, which needs to be used by the Application to request the reception activation from the MBMS Client.
3: The Content Provider provides the Master Playlist. It also provides the IS, with identifying source URI, for each Media Playlist to be broadcast. The source URI should match the EXT-MAP tag within the corresponding Media Playlist. Note that the Master Playlist and the collection of IS will be provided via the SACH to the MBMS Client.
4: The MBMS client receives the service access information.
5: At Playlist reload intervals as specified by RFC 8216 section 6.3.4, the BM-SC Pulls, via HTTP GET, Media Playlist updates, which specify all segment(s) currently available. Following this the BM-SC Pulls any media segments it has not yet ingested. The BM-SC then wraps the Media Playlist and the new media segment(s) into MBMS Download Delivery Objects.
6: The BM-SC sends the CMAF Segment(s) as MBMS Download Delivery Objects together with the corresponding Media Playlists.
7: Steps 5 and 6 are repeated until the session schedule end time is reached.
A.5.4 HLS Content Ingestion with Push
A.5.4.1 Introduction
The Content Provider delegates all MBMS related complexity to the operator and provides HLS compliant content using an HTTP PUT method to the BM-SC. The Content Provider is responsible for ensuring the order of media segments and Media Playlist availability to the BM-SC over the xMB-U.
The following Session Properties allow the configuration of this xMB-U mode.
– Session Type is set by the Content Provider to Application.
– Ingest Mode (Session Type specific property) is set by the Content Provider to Push.
– The BM-SC provides the Push URL (Session Type specific property) to the Content Provider. The value of this property is configured to the HLS packager.
– Application Service Description (Session Type specific property) is set to application/vnd.apple.mpegurl.
– Application Entry Point URL contains the URL to the HLS Master Playlist. The BM-SC will fetch the Master Playlist using the value of the Application Entry Point URL and embed the Master Playlist into the Service Announcement File (SACH).
A.5.4.2 Content ingestion steps
Steps 1 to 4 are identical to clause A.5.3.
5: At segment Duration intervals, the Content Provider pushes a new media segment to the BM-SC. The BM-SC then wraps it into an MBMS Download Delivery Object.
6: Following each segment push, the Content Provider pushes to the BM-SC a Media Playlist update that now specifies the segment made available in step 5. The BM-SC then wraps it into an MBMS Download Delivery Object.
7: The BM-SC sends the CMAF segment(s) together with the corresponding Media Playlist update as MBMS Download Delivery Objects.
8: Steps 5 to 7 are repeated until the session schedule end time is reached.
Annex B (informative):
Change history
|
Change history |
|||||||
|
Date |
Meeting |
TDoc |
CR |
Rev |
Cat |
Subject/Comment |
New version |
|
2018-09 |
SA#81 |
SP-180654 |
Presented to TSG SA#81 (for information) |
1.0.0 |
|||
|
2018-12 |
SA#82 |
SP-180980 |
Presented to TSG SA#82 (for approval) |
2.0.0 |
|||
|
2018-12 |
SA#82 |
Approved at SA#82 |
16.0.0 |
||||
|
2019-03 |
SA#83 |
SP-190033 |
0002 |
2 |
B |
Support of profile 1c |
16.1.0 |
|
2019-06 |
SA#84 |
SP-190340 |
0003 |
1 |
B |
Support for Multiplexing MCData Sessions on one MBMS Bearer |
16.2.0 |
|
2019-06 |
SA#84 |
SP-190340 |
0005 |
– |
F |
Correction of xMB Guidelines |
16.2.0 |
|
2020-03 |
SA#87-e |
SP-200039 |
0006 |
1 |
B |
Guidelines for HLS Media Presentation Delivery |
16.2.0 |
|
2020-03 |
SA#87-e |
SP-200039 |
0007 |
1 |
B |
Support of hybrid HLS/DASH services |
16.3.0 |
|
2022-04 |
– |
– |
– |
– |
– |
Update to Rel-17 version (MCC) |
17.0.0 |
|
2022-06 |
SA#96 |
SP-220597 |
0008 |
[5MBP3] xMB Extensions for 5GMS via eMBMS |
17.1.0 |
||