# Summary of S4-260102: Introduction to TR 26.836 on QUIC-based Media Delivery

## Document Overview

This contribution provides the foundational introduction for TR 26.836, which addresses the study item FS_Q4RTC_MED approved in SA#110. The objective is to identify and document existing and emerging QUIC-based media delivery protocols suitable for real-time communication.

## Main Technical Contributions

### 1. QUIC Protocol Foundation

The document establishes the baseline understanding of QUIC by referencing the core IETF specifications:

- **RFC 9000**: Core QUIC transport mechanisms (UDP-based, multiplexed, secure)
- **RFC 9001**: TLS 1.3 integration for security
- **RFC 9002**: Loss detection and congestion control
- **RFC 8999**: Version-independent properties

Additional extensions and operational specifications are referenced:
- **RFC 9114**: HTTP/3
- **RFC 9221**: Unreliable datagram extension
- **RFC 9309**: Applicability guidance
- **RFC 9312**: Manageability aspects

### 2. Key Motivations for QUIC in Media Transport

The contribution identifies several technical advantages of QUIC for media delivery:

#### Lower Latency and Faster Start-up
- 1-RTT handshake with optional 0-RTT resumption reduces join time
- User-space pacing algorithms minimize burstiness and reduce jitter

#### Independent Stream Processing and Prioritization
- Eliminates head-of-line (HoL) blocking across different streams
- Prevents one stalled media flow from blocking others (e.g., video frame not blocking audio)
- Stream prioritization enables resource allocation based on application-signaled importance

#### Selective Reliability
- **Datagrams** (RFC 9221): Best-effort delivery for latency-critical applications requiring unordered, unreliable packet delivery
- **Streams**: Reliable, ordered delivery with explicit prioritization
- Applications can mix both approaches based on data criticality and delay sensitivity

#### Always-on Security
- Built-in TLS 1.3 encryption and authentication eliminates need for separate DTLS layer
- Connection IDs (CIDs) and encrypted headers improve privacy
- Resilience to middlebox ossification

#### Better Mobility and Robustness
- Connection migration enables seamless IP/port changes (e.g., Wi-Fi to cellular transitions)
- Avoids call drops and renegotiations that disrupt audio/video continuity

### 3. IETF QUIC-based Application Protocols

The document identifies three QUIC-based application protocols under IETF standardization for real-time and interactive communication:

- **MOQT (Media over QUIC Transport)**: draft-ietf-moq-transport-16
- **ROQ (RTP over QUIC)**: draft-ietf-avtcore-rtp-over-quic-14
- **WebTransport**: draft-ietf-webtrans-overview-11

### 4. Normative References

The contribution adds comprehensive normative references covering:
- Core QUIC specifications (RFCs 8999, 9000, 9001, 9002)
- QUIC extensions (RFCs 9114, 9221)
- QUIC operational guidance (RFCs 9309, 9312)
- Security foundation (RFC 8446 - TLS 1.3)
- IETF work-in-progress drafts for MOQT, ROQ, and WebTransport

## Document Structure

The changes propose additions to:
- **Clause 1 (Introduction)**: Complete technical introduction to QUIC and its benefits for media transport
- **Clause 2 (References)**: Addition of 12 new normative references ([y1] through [y12])