# 3GPP TR 26.501 Change Request Summary

## Document Information
- **CR Number**: Pseudo CR for TR 26.958 v0.1.1
- **Category**: B (addition of feature)
- **Release**: Rel-20
- **Work Item**: FS_3DGS_MED
- **Source**: Samsung Electronics Co. Ltd.

## Purpose
This CR addresses the mapping of 3D Gaussian Splatting (3DGS) services to 3GPP services and specifications for the **Client-Server configuration**. This complements the existing All-in-UE configuration mapping.

## Main Technical Contributions

### Clause 10.2: Client-Server Configuration Mapping

The CR introduces a comprehensive mapping table that defines how different 3DGS workflow functions map to existing 3GPP services when operating in a Client-Server configuration. In this configuration, 3DGS is delivered as either an **interactive XR service** or **6DoF media streaming**.

#### Content Generation
- **UE-side 2D Capture**: Maps to Media-Aware Application (TS 26.501) and Split Rendering Client (TS 26.565)
- **Network-side 3DGS Generation**: Maps to (Edge) Media AS of Media Delivery architecture (TS 26.501), including:
  - 3DGS scene generation from 2D capture
  - Dynamic 3DGS content
  - Region-based parts of 3DGS scenes

#### Caching
- **3DGS Model and Tile Caching**: Utilizes 5G Edge CDN infrastructure

#### Delivery
- **Streaming/Real-time Communication**: Supports tiled LOD streaming using:
  - Adaptive media delivery protocols (DASH, HLS, RTP, QUIC)
  - Partial delivery or on-demand streaming
- **3GPP Mapping**: (Edge) Media AS and Media Access Function (TS 26.501), Split Rendering Server (TS 26.565)

#### Network Rendering
- **Edge Rendering**: Partial or full network edge rendering
- **3GPP Mapping**: (Edge) Media AS (TS 26.501) and Split Rendering Server (TS 26.565)

#### UE Rendering/Playback
- **Client-side Rendering**: Maps to Media-Aware Application (TS 26.501) and Split Rendering Client (TS 26.565)

#### Pose/LOD Reporting
- **Uplink Reporting**: Maps to:
  - Media-Aware Application (TS 26.501) and Split Rendering Client (TS 26.565) for pose/LOD capture
  - Real-time/conversational service interfaces (TS 26.506) for transfer of pose and LOD information to generate view/LOD dependent 3DGS content

### 5G QoS Considerations (NOTE 1)

The CR identifies key 5G QoS requirements for 3DGS service delivery (marked as FFS for final determination):

#### Performance Requirements
- **High bit rates/bandwidth/throughput**: Leveraging 3GPP eMBB
- **Low to Ultra Low Latencies**: Utilizing 5G URLLC
- **Low jitter delivery**

#### XR-Specific QoS Features
- New 5QI for XR services
- PDU Set based QoS with parameters:
  - PDU Set Error Rate
  - PDU Set Delay Budget
  - PDU Set Size
- Alternative QoS Profiles

#### Network Architecture Features
- **Service Stability**: Using 5G Network Slicing (e.g., dedicated network slice for 3DGS delivery) per TS 23.501
- **Edge Computing**: Caching with edge CDNs and network processing (generation, rendering) per TS 26.501 and TS 23.558
- **Multicast/Broadcast**: Distribution to multiple users per TS 26.502

### Additional Considerations (NOTE 2)
For Avatar-related 3DGS services, TS 26.264 may be applicable.

## Impact
This CR completes the study on mapping 3DGS to 3GPP services by addressing the Client-Server configuration, which is essential for network-assisted 3DGS delivery scenarios including edge rendering and adaptive streaming use cases.