Summary of S4-260276: Media over QUIC

1. Introduction and Context

This contribution addresses the FS_QStream_MED Rel-20 study (SP-251659), which evaluates whether current and future media services could benefit from QUIC-based streaming technologies compared to TCP-based technologies (HTTP 1.1 and HTTP/2). The document provides information on Media-over-QUIC (MoQ) as one of the emerging QUIC-based streaming technologies identified in TR 26.804.

2. Media over QUIC (MoQ) Overview

MoQ is an IETF working group effort standardizing a publish/subscribe media delivery system over QUIC and WebTransport-over-HTTP/3, designed for high-scale, low-latency delivery with explicit support for intermediaries (relays, caches, replication points).

2.1 Core MoQ Working Group Drafts

As of February 2, 2026, the MoQ WG has four core drafts:

• Media over QUIC Transport (MoQT): Main wire protocol defining publisher/subscriber operations over QUIC/WebTransport
• MOQT Streaming Format (MSF): Streaming format specifying media structure for MOQT delivery
• CMSF (CMAF-compliant MSF): Extension defining optional feature to carry CMAF-packaged media within MSF over MOQT
• Authentication scheme for MOQT using Common Access Tokens: Authentication scheme enabling client authentication to relays/servers

2.2 Media over QUIC Transport (MoQT) Technical Details

2.2.1 Protocol Foundation

MoQT builds upon:
- QUIC or WebTransport as underlying transport
- HTTP/3 as application-layer substrate
- Publisher-subscriber communication model
- Optional relay-based distribution mechanisms

2.2.2 Content Organization and Object Model

Content is organized hierarchically as Track → Group → Object:

• Track: Subscribable unit representing logical timeline for one stream of related content (e.g., video encoding, audio language, captions). Publishers advertise/publish Tracks; subscribers subscribe to Tracks.

• Group: Ordered collection of Objects within a Track, serving as join point. Subscribers can start at Group beginning and decode without prior Group information. Groups align with random-access boundaries (e.g., GOP/IDR boundaries for video).

• Object: Smallest named/addressable payload unit delivered. Contains bytes plus identifiers (Track + Group + Object IDs) and optional metadata. Objects are what relays forward and potentially cache, and the unit MoQT schedules over QUIC streams/datagrams.

2.2.3 Mapping MoQ Object Model to MPEG-DASH

The contribution provides detailed mapping between MoQ and DASH concepts:

• MoQ Track ↔ DASH Representation (one encoded bitstream at given quality)
• Set of related Tracks ↔ DASH AdaptationSet (multiple bitrates or alternate languages)
• MoQ Group boundary ↔ DASH segment boundaries (switching/random-access points aligned with RAP/IDR)
• MoQ Objects ↔ Within-segment granularity (CMAF movie fragments/moof-mdat pairs for latency and scheduling)

2.3 MoQ Streaming Format (MSF)

MSF is the standardized media packaging and signaling layer on top of MOQT, defining how to package and map streaming media onto MoQT's Track/Group/Object abstractions.

2.3.1 Key MSF Features

• Catalog concept: Published over MOQT, describes existing Tracks and relationships (render groups, packaging used)
• Timeline information: Defines how publishers convey timeline information and updates using MOQT Objects within Groups (independent event timeline in first Object of each Group, with optional incremental updates)
• Time-alignment requirements: Tracks in common render group must be time-aligned with corresponding Groups overlapping in presentation time after decoding
• ABR support: Provides format-level conventions for receivers to understand alternative encodings, time alignment, and safe switching for continuous playback

2.3.2 CMAF Integration

CMSF (CMAF-compliant MSF) extends MSF by defining optional feature specifying syntax and semantics for carrying CMAF-packaged media within MSF framework while retaining MSF's catalog/timeline/switching concepts.

3. Implementations and Deployments

3.1 Implementations/Players

• MoQtail: Libraries for publisher, subscriber, and relay components with media application demos using LOC and CMSF formats
• Shaka Player: Experimental support for MoQT draft-14 and MSF draft-1
• Meta's MoQ-Encoder-Player: Minimal in-browser live video/audio encoder and player based on MOQT draft
• Meta's moxygen: Experimental media MOQ relay for use with moq-encoder-player
• moq-dev: Rust and TypeScript MoQ libraries with similar APIs but language-specific optimizations

3.2 Deployments

• Cloudflare MoQ relay network: Technical preview running MoQ relay network across global edge footprint (every Cloudflare server across hundreds of cities) with public documentation
• WINK: Open-source MoQ implementation integrated with MediaMTX, production-tested for live/surveillance streaming with sub-second latency

4. Proposal

The contribution proposes to include the contents of section 2 in the new TR 26.835.