# Summary of 3GPP Technical Document S4-260087

## Document Information
- **CR Number**: 0604 rev 1
- **Specification**: TS 26.114 v19.2.0
- **Category**: F (Correction)
- **Release**: Rel-19
- **Work Item**: 5G_MEDIA_MTSI_ext, TEI19

## Main Technical Contribution

### Problem Statement
The current constraint in TS 26.114 clause 6.2.10.1 states that a data channel SDP media description shall not be placed before the first SDP speech media description. This constraint is no longer applicable because 3GPP R19 SA2 has specified **standalone data channel sessions** that can establish data channels without MMTel media (e.g., audio, video, messaging).

### Proposed Change

#### Modification to Clause 6.2.10.1 (General)

The CR proposes to remove the restrictive placement constraint for data channel SDP media descriptions. Specifically:

**Deleted Text:**
- "A data channel SDP media description shall not be placed before the first SDP speech media description."

**Modified Text:**
The sentence describing data channel SDP media description inclusion is updated from:
- "One or more data channel SDP media descriptions formatted according to IETF RFC 8864 [172] may be contained alongside other SDP media descriptions such as e.g. speech, video, and text."

To:
- "One or more data channel SDP media descriptions formatted according to IETF RFC 8864 [172] may be **added into the SDP independently, or to be added** alongside other SDP media descriptions such as e.g. speech, video, and text."

### Technical Impact

This correction enables:
- **Standalone data channel sessions** without requiring MMTel media components
- **Flexible SDP ordering** where data channel media descriptions can appear in any position within the SDP
- **Alignment with SA2 specifications** for Rel-19 standalone data channel functionality

### Unchanged Requirements

The following requirements remain intact:
- Support for data channel media remains optional for MTSI clients
- Media feature tag requirements (+sip.app-subtype with "webrtc-datachannel" value)
- g.3gpp.dc-mux media feature tag for bootstrap and application data channel multiplexing
- Protocol identifier and media format specifications (UDP/DTLS/SCTP and webrtc-datachannel)
- Bandwidth limit determination requirements per clause 6.2.5