# 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.