Summary of 3GPP TR 26.501 Change Request

Document Information

• Meeting: 3GPP TSG-S4 Meeting #135, Goa, India (9-13 February 2026)
• Document Number: S4-260247
• CR Type: Category B (addition of feature)
• Release: Rel-20
• Work Item: FS_3DGS_MED (3D Gaussian Splatting Media Study)

Main Purpose

This CR introduces high level media data workflows for Client-Server configuration in the context of 3D Gaussian Splatting (3DGS) service delivery. This complements the existing all-in-client configuration by defining workflows where functionality is split between the UE client and the network server.

Technical Contributions

New Clause 9.2: Client-Server Configuration

9.2.1 Description

• Defines media data workflows where functionality is split between client and server (network)
• Supports interactive navigation in large or dynamic 3DGS scenes
• Enables network-assisted processing for resource-intensive operations

9.2.2 Media Workflow Steps

9.2.2.1 Workflow Description

The CR identifies the following workflow steps that execute in the Client-Server configuration:

Server-Side Operations:
- 3DGS Content Generation: Generation of 3DGS content from 2D captures of scenes (references clause 5.2)
- Dynamic Content Generation: Creation of dynamic 3DGS content and region-based parts of 3DGS scenes based on the 3DGS model for adaptive delivery
- Adaptive Selection: Selection of 3D tiles and their Level of Detail (LOD) based on:
- User movement
- UE device capabilities
- Packaging and Distribution: 3DGS assets packaged in the network and delivered via:
- MMS
- OTT messaging
- Download services

Client-Side Operations:
- Content Reception: UE receives one or more of:
- 3DGS assets (clause 5.2)
- 3D tiled LODs (clause 5.3)
- Dynamic 3DGS scene content via file delivery, partial-delivery, or on-demand streaming (clause 5.4)
- Storage: Content stored in local memory or GPU memory
- Rendering: UE renders:
- 3DGS assets by selecting Gaussians based on LODs dependent on:
- User preferences
- UE device capabilities and characteristics (camera pose, display resolution, etc.)
- 3D tiled LODs fetched using adaptive delivery (clause 5.3)
- 3D Avatars using time-aligned animation streams (clause 5.5)

9.2.2.2 Characteristics

The CR defines key characteristics of the client-server configuration:

Latency/Performance:
- Dependent on network and application latency
- Influenced by:
- Capabilities of the network server generating 3DGS content
- UE device rendering capabilities

Scalability:
- Enhanced scalability compared to all-in-client configuration
- Leverages theoretically infinite network resources
- Enables more use cases

Network Usage:
- Content generation
- Rendering (full or partial)
- Distribution

Network Interaction During Playback:
- Selection of 3D tiles and LODs
- Sending user pose information
- Temporal updates
- Optional partial or full rendering support

Affected Clauses

• Clause 9.2: New clause added for Client-Server configuration

Relationship to Existing Work

This CR builds upon:
- Clause 5 use cases (referenced throughout)
- Clause 9.1 All-in-client configuration (complementary approach)
- Various delivery mechanisms already defined in the study (MMS, OTT messaging, file delivery, streaming)