Summary of S4-260103: Considerations on Application Scenarios for FS_Q4RTC_MED
1. Introduction and Context
This contribution from Nokia (as rapporteur) addresses the definition of application scenarios for the study on QUIC-based media delivery protocols in the context of the RTC System (FS_Q4RTC_MED). The scenarios will serve as the basis for evaluating QUIC-based media delivery protocols against existing WebRTC and (S)RTP-based frameworks as defined in TS 26.506 and TS 26.113.
2. Evaluation Plan Framework
The document references Objective 2 of the SID, which establishes three main evaluation components:
a) Evaluation Framework Definition
- Define application scenarios for QUIC-based media delivery protocol evaluation
- Include existing 3GPP services or service enablers (e.g., split rendering)
b) Performance Evaluation
- Define appropriate performance metrics and requirements for identified scenarios
- Evaluate QUIC-based protocols against existing architectures under realistic 3GPP network conditions
- Consider existing performance evaluations from academia and other SDOs
- SA4 may analytically verify results without conducting new simulations
c) Deployment Impact Assessment
- Document potential impact on delivery architecture (TS 26.506)
- Consider current architectures, 3GPP core network (TS 23.501), and UE implementations
- Identify advantages and disadvantages regarding efficiency, scalability, distributed deployment, radio optimizations, flow control, security/privacy vs. traffic management, and implementation readiness
Notes:
- Evaluation framework may be based on open-source network simulators (e.g., ns3)
- Scenarios involve real-time audio/video communication using EVS, IVAS, H.264/AVC, and H.265/HEVC codecs
3. Key Aspects for Application Scenario Definition
The document identifies critical aspects that must be considered when defining application scenarios:
Relevance to 3GPP Ecosystem
- Scenarios must reflect actual or anticipated 3GPP services and use cases
- Should describe how QUIC-based media delivery protocols (identified in TR 26.836 clause 4) will be applied
- Should detail how specific QUIC features (e.g., stream prioritization) may be leveraged
- Should identify relevant media streams and control signaling (uplink/downlink) and their mapping to QUIC and QUIC-based protocols
Performance Characteristics
- Latency: Define target latencies for considered media types and interactions
- Jitter tolerance: Define acceptable jitter ranges for packet arrival time variability
- Packet loss resilience: Document acceptable packet loss levels balancing reliability vs. latency
- Throughput and bitrate adaptability: Specify necessary bitrates and adaptive streaming requirements
- Security and privacy: Consider implications of QUIC's built-in encryption
Evaluation Approach
The document acknowledges that not all scenarios will undergo network simulation using TR 26.934 test framework due to time and resource limitations. When simulation is not possible, analytical assessment of architectural and deployment impact should still be conducted.
4. Proposed Scenario Template
A standardized template is proposed for scenario definition with the following structure:
1. Scenario Name
Descriptive name (e.g., "Interactive XR Split Rendering")
2. Description
Brief narrative explaining use cases, user interaction, and overall goal (example provided: XR headset user in collaborative design review with cloud rendering and 5G handovers)
3. Relevance to 3GPP Ecosystem
Explanation of relationship to actual or anticipated 3GPP services and service enablers
4. Application of QUIC
- Description of how QUIC-based media delivery protocols (from TR 26.836 clause 4) apply to the scenario
- Details on leveraging specific QUIC features (reliable/unreliable streams, stream prioritization, connection migration)
- Discussion of security and privacy aspects impacted by QUIC usage
5. Media Stream and Control Signaling Characteristics
- Media type
- Bitrate requirements
- Latency/jitter sensitivity
- Loss tolerance
- Communication pattern (e.g., point-to-point, multi-party)
- Directionality (e.g., unidirectional media streams, bidirectional control streams)
5. Proposals
The document proposes two actions:
- Consider the aspects outlined in clause 3 when proposing new application scenarios
- Provide scenario definitions based on the template given in clause 4
Technical Contributions Summary
This contribution establishes a structured methodology for defining and evaluating application scenarios in the QUIC-based RTC media delivery study. The main technical contributions are:
- Comprehensive evaluation criteria covering latency, jitter, packet loss, throughput, and security considerations specific to RTC applications
- Standardized scenario template ensuring consistent and complete scenario descriptions across contributions
- Clear mapping requirements between application needs and QUIC protocol features
- Flexible evaluation approach allowing both simulation-based and analytical assessments
- Focus on 3GPP ecosystem relevance ensuring scenarios address actual or anticipated service requirements