Proposals

Proposal 1: Acknowledge 3D Gaussian Splatting as a viable rendering primitive for avatar communication.

Proposal 2: Coordinate with MPEG on the integration of Gaussian splatting data within the ARF Base Avatar Format (ISO/IEC 23090-39).

Proposal 3: Evaluate compression techniques (SPZ, L-GSC, HAC++, Compact3D) for inclusion in the study of static and animation data compression (Objective 7).

Proposal 4: Define capability signaling and conformance points for 3DGS avatar rendering, including supported Gaussian count budgets, supported attribute sets, and required numerical tolerances for determinism.

Proposal 5: Study whether hybrid approaches with small MLPs warrant an optional ARF profile, and if so constrain operator sets and model sizes to preserve portability.

Proposal 1: Adopt an objective evaluation approach based on rendered video output as the primary evaluation method to ensure reproducibility of the results.

Proposal 2: Include the proposed metric set covering visual quality (PSNR, SSIM), animation fidelity (LVE, FDD, MVE), and temporal performance (latency, frame rate, A/V sync) in TR 26.813.

Proposal 3: Define a normative capture workflow using lossless recording, timecode embedding, and reference alignment to enable consistent metric computation across implementations.

Proposal 1: Document the content of sections 2 and 3 in TR 26.813.

Proposal 2: Recommend adding explicit text to TS 26.264 clause 5.6.1 stating that the avatar owner shall ensure that the identifiers used in avatar animation streams either directly match the identifiers of the target Skeleton, BlendshapeSet, and LandmarkSet stored in ARF, or that mapping tables are present in the ARF document to convert from the stream profile to the target assets.

Proposal 3: Recommend removing the corresponding note from TS 26.264 and declaring it as resolved.

This document does not contain any technical proposals. It is a Liaison Statement (LS) from 3GPP TSG SA WG4 to ISO/IEC JTC1/SC29 working groups, asking questions about compression technologies for avatar data. The document contains questions and an action request, but no proposals in the format typically found in 3GPP technical documents.

Proposal: It is proposed to add a sub clause (e.g. 8.3.4, under the umbrella of clause 8 - Avatar integration into 3GPP services and enablers) in the base CR to TR 26.813 dedicated to address security aspects, primarily focusing on the security mechanisms and solutions (e.g. authentication, encryption, content protection) for Avatar calls via the generalized IMS DC architecture.

Proposals

Proposal: It is proposed to add a new sub-clause 8.3.4 with the text as below:

Proposal: It is proposed to add above content in the base CR.

Proposal: It is proposed to agree to send an LS to SA2 requesting clarification on the IMS network's behavior with respect to received SIP REGISTER messages with Contact header field parameters, for which a proposed draft LS is provided in S4-260227.

There are no proposals in this document.

This is a Liaison Statement (LS) from SA4 to SA2 regarding IMS network behavior for new Contact header parameters. The document contains questions and action items, but no formal proposals.

Proposal: Update section 6.3.4 of the AVATAR specification to reflect the latest developments in the MPEG Avatar Representation Format, including:

• Updated status to reflect that ISO/IEC 23090-39 has reached committee Draft International Standard (CDIS) stage
• Revised description of the representation baseline format to align with the current data model structure (preamble, components, etc.)
• Addition of detailed information about the ARF animation bitstream format, including Avatar Animation Units (AAUs) and their types
• Updated description of ongoing exploration experiments

Proposal

It is proposed to document the contents of section 2 of this contribution as a new clause 8.3.3.4 in the aggregated CR to TR 26.813, and to provide an editor's note to clause 8.3.3.2 to indicate that the clause needs to be updated to reflect the BAR APIs defined in TS 26.264.

Proposal

It is proposed to agree the changes below to section 6.3.4 into the consolidated CR.