# Summary of 3GPP Technical Document S4-260238

## Document Information
- **CR Number**: 0014
- **Specification**: TS 26.117 v19.1.0
- **Category**: A (mirror CR for earlier release)
- **Release**: Rel-19
- **Work Item**: IVAS_Codec

## Purpose and Rationale

This Change Request addresses the incomplete referencing of IVAS codec levels defined in TS 26.250. The document removes placeholder "TBD" (To Be Determined) notes regarding IVAS codec level settings and replaces them with proper references to IVAS level-specific capabilities (Level 1, Level 2, and Level 3).

## Main Technical Contributions

### 1. Decoding Capabilities (Clause 5.2)

**Additions:**
- Introduced three new IVAS level-specific decoding capabilities:
  - **IVAS-L1**: All decoding and rendering requirements for Level 1 of the IVAS codec
  - **IVAS-L2**: All decoding and rendering requirements for Level 2 of the IVAS codec
  - Both reference the complete set of IVAS specifications (TS 26.250-26.256, 26.251, 26.258)

**Clarifications:**
- Maintained existing IVAS capability definition (all levels)
- Maintained IVAS-SR (split rendering) capability definition
- Retained NOTE clarifying that IVAS decoder support implies EVS decoding capability support

### 2. Encoding Capabilities (Clause 5.3)

**Additions:**
- Introduced two new IVAS level-specific encoding capabilities:
  - **IVAS-L1**: All encoding requirements for Level 1 of the IVAS codec
  - **IVAS-L2**: All encoding requirements for Level 2 of the IVAS codec
  - Both reference TS 26.250, 26.252, 26.253, 26.251 (fixed-point), and 26.258 (floating-point)

**Clarifications:**
- Maintained existing IVAS capability definition (all levels)
- Retained NOTE clarifying that IVAS encoder support implies EVS encoding capability support

### 3. IVAS Operation Point - Receiver Requirements (Clause 6.3.5.2)

**Changes:**
- **Removed**: "NOTE: IVAS codec level setting is TBD"
- **Modified**: Updated receiver requirements to explicitly reference support for "respective IVAS, IVAS-L1, IVAS-L2 or IVAS-SR media decoding capability according to clause 5.2 and to the supported IVAS codec level 1, 2 or 3 or the IVAS split rendering feature"
- Retained NOTE about EVS backward compatibility

### 4. IVAS Operation Point - Sender Requirements (Clause 6.3.5.3)

**Changes:**
- **Removed**: "NOTE: IVAS codec level setting is TBD"
- **Modified**: Updated sender requirements to reference "respective IVAS, IVAS-L1 or IVAS-L2-Enc media encoding capability according to clause 5.3 in real-time for the audio formats according to the supported IVAS codec level 1, 2 or 3"

### 5. Content Generation Requirements (Clause 7.5.2.5)

**Changes:**
- Updated to reference support for "all media encoding capabilities for IVAS, IVAS-L1 or IVAS-L2 as defined in clause 5.3"
- Updated sender requirements reference to "IVAS, IVAS-L1 or IVAS-L2 as defined in clause 6.3.5.3"

## Impact

**Consequences if not approved:**
- Implementers may be confused about required IVAS encoder/decoder capabilities for given services
- Lack of clarity on which codec level implementations are needed for specific use cases
- Ambiguity in conformance testing and implementation requirements

## Technical Specifications Referenced

- TS 26.250-26.256: IVAS codec specifications
- TS 26.251: IVAS fixed-point implementation
- TS 26.258: IVAS floating-point implementation
- Multiple EVS, AMR-WB, and other codec specifications (context)