Summary of S4-260184: Application Manifest for AIML Applications

1. Introduction

This contribution proposes IMS Data Channel (DC) application metadata for AI/ML applications. The document merges metadata elements from S4aR250213 and S4aR250208 based on previous RTC SWG discussions and email exchanges. It addresses comments from RTC Telco Post SA4#134-2 regarding the origin and transfer of the AIML application manifest.

2. Main Technical Contributions

2.1 General Framework for AI/ML Support over Data Channel

The contribution defines AI/ML DC applications as IMS DC applications that:
- Interact with AI/ML models (e.g., performing inference on UE)
- Communicate AI/ML data
- Support different inference paradigms: local inference, remote inference, and split inference

Key architectural elements:
- DCSF (via MF) provides policy and subscription-appropriate data channel applications to UE
- DC Application Repository (DCAR) stores verified data channel applications
- DCSF downloads applications from DCAR for distribution to UE
- DCMTSI client uses metadata to select appropriate toolchains or execution environments

2.2 Base Application Manifest Structure

The manifest contains essential information for AI/ML DC applications:

Core elements:
- baseUrl: URI template for downloading models with format: baseurl/$taskId$/$version$/$framework$/$subtask$/$variant$/model.$format$
- tasks: Array of AI tasks enabled by the application
- taskParameters: Configuration parameters for different conditions
- models: Array of AI/ML model objects with metadata

Task-level metadata includes:
- taskId: Unique identifier
- taskName/description: Human-readable task identifier (e.g., "Speech-to-speech Translation")
- version: Task version number
- capabilityIndex: Minimum capability requirements
- executionCandidate: Supported endpoint locations (e.g., UE or MF)

2.3 Task Input/Output Specification

Task inputs (taskInputs):
- taskInputId: Unique identifier
- media-type: Input media type
- route-to: Specifies subtaskInputId for data routing

Task outputs (taskOutputs):
- taskOutputId: Unique identifier
- media-type: Output media type
- from: Specifies subtaskOutputId for output data origin

2.4 Model Metadata

Each model object contains:
- id: Unique model identifier
- version: Model version/variant
- capabilityIndex: Minimum capability requirements
- url: Model download location
- latency: Maximum latency requirement (milliseconds)
- accuracy: Minimum accuracy requirement (metrics/value/direction - FFS)

2.5 Subtask Metadata (Extension Parameters)

For tasks comprising multiple subtasks, the manifest includes detailed subtask information:

Subtask-level parameters:
- id: Unique subtask identifier
- function: Description of subtask function
- capabilityIndex: Capability requirements (matches AI model capability)
- executionTarget: Intended endpoint location
- executionFallback: Alternative endpoint when primary unavailable

Subtask inputs (subtaskInputs):
- subtaskInputId: Unique identifier
- pipe-type: Logic for multiple data inputs (0=first available, 1=wait for all)
- media-type: Input media type
- from: Origin subtaskOutputId or taskInputId

Subtask outputs (subtaskOutputs):
- subtaskOutputId: Unique identifier
- media-type: Output media type
- route-to: Destination subtaskInputId or taskOutputId

Subtask AI model parameters:
- id, capabilityIndex, url, latency, accuracy (as per main model metadata)
- contextSize: Maximum input data amount the model can process (typically in tokens)

3. Open Issues

Several aspects remain FFS (For Further Study):
- Editor's Note: Definition of AI/ML task may be needed (referencing TS 26.927)
- Editor's Note: Whether all fields in tables are needed and their definitions
- Editor's Note: Capability index definition and usage
- Editor's Note: Clear definition of accuracy metrics
- Editor's Note: Pipe-type parameter needs further clarification
- Model metadata specification alignment with TR 26.927

4. Document Type

This is a text proposal for the AI_IMS_MED work item, proposing new clauses (marked as "All New Text") to be added to the base CR.