Summary of S4-260259: Application Scenario for Peer to Application (P2A) with Split Rendering

Document Overview

This Change Request introduces a new application scenario for the Study on QUIC-based media delivery for real-time communication (RTC) services. The contribution focuses on defining the Peer to Application (P2A) scenario with split rendering as specified in TS 26.506 and TS 26.565.

Main Technical Contributions

1. References Update

The document adds a new normative reference:

• 3GPP TR 22.870: "Study on 6G Use Cases and Service Requirements" - This reference provides the foundation for the interactive application scenarios described in the contribution.

2. New Application Scenario: Real-time Interactive Applications with Split Rendering

2.1 Architecture and Functional Split

The contribution defines a split rendering architecture where:

• Peer Device Functions:
• User interaction capture
• Local sensing
• Final presentation
• Acquisition of user inputs and contextual information (motion, pose, audio, video, spatial/environmental data, sensor information)

• Transmission of captured data to application server

• Application Server Functions:

• XR/gaming scene updates
• Processing of received inputs
• Application logic execution
• Physics simulations
• AI-based processing
• Scene rendering
• Transmission of rendered frames (2D video) and additional media (audio, haptics) to peer device

2.2 Communication Characteristics

The scenario requires:

• Bidirectional communication path maintained throughout the session
• Critical performance requirements: End-to-end latency, jitter, and reliability
• Security requirements: Secure connections and encryption for privacy of sensitive data
• Multi-modal stream support: Audio, video, 2D/3D graphics, haptic feedback

2.3 Deployment Scenarios

Two operational modes are defined:

• Single-user scenario: Application server receives pose, sensor updates, and video from device camera, updates scene in real-time, and sends rendered media back
• Multi-user scenario: Shared application state (virtual scene, digital objects, avatars) maintained at application server and consistently synchronized between server and all peers in real-time

2.4 Network and Resource Requirements

The contribution identifies specific network support needs:

• Differentiated connectivity for interactive services
• Low-latency and high-reliability communication for multi-modal streams
• Coordination between communication, computing, and rendering resources
• Support for dynamic offloading of compute-intensive and rendering functions due to device constraints (form factor, energy consumption, rendering capabilities)

2.5 Applicable Use Cases from TR 22.870

The contribution maps the P2A split rendering scenario to three specific use cases from TR 22.870:

1. Immersive gaming (clause 9.2): Real-time immersive gaming and XR with multi-modal inputs, remote compute-intensive rendering and AI processing, requiring secured low-latency bidirectional media delivery

2. XR rendering offload support (clause 9.4): Lightweight XR devices offloading rendering and processing to edge/cloud servers, requiring real-time exchange of user inputs and rendered media with tight latency constraints and network-assisted optimization

3. Mixed reality gaming (clause 9.9): Multiplayer MR gaming with synchronized virtual scene based on common spatial map, continuous upload of environmental data to cloud server, real-time scene updates distribution to all participants under varying mobility and network conditions

Technical Significance

This contribution establishes a foundational application scenario for evaluating QUIC-based media delivery protocols in the context of split rendering services. It clearly defines the functional split, communication requirements, and maps to existing 6G use case requirements, providing a concrete basis for protocol evaluation and optimization work in the study item.