# Summary of 3GPP CR S4-260086

## Change Request Details
- **Specification:** TS 26.114 v19.2.0
- **CR Number:** 0606
- **Category:** A (mirror CR)
- **Release:** Rel-19
- **Work Item:** IVAS_Codec

## Main Technical Contribution

### Problem Statement
This CR addresses an inconsistency in the bandwidth computation procedure for the IVAS codec specified in clause Z.2 of TS 26.114. The current procedure includes RTCP bandwidth in the b=AS (Application-Specific maximum bandwidth) calculation, which is inconsistent with:
- Bandwidth computation procedures for other codecs
- General session setup procedures defined in clause 6.2.7.2

### Technical Solution

The CR modifies the bandwidth computation procedure in clause Z.2 by **removing step 5** which adds bandwidth for RTCP to the b=AS calculation.

#### Modified Procedure
The updated bandwidth calculation procedure for IVAS codec (when no extra bandwidth is allocated for redundancy) now consists of:

1. Use the highest negotiated bitrate for IVAS codec from SDP (using ibr or ibr-recv parameters if specified)
2. Calculate bitrate for RTP payload header
3. Add bandwidth for PI (Primary Importance) data (using pi-br or pi-br-recv parameters if specified)
4. Add bandwidth for IP, UDP and RTP headers assuming 50 frames per second:
   - 16 kbps for IPv4
   - 24 kbps for IPv6
5. ~~Add bandwidth needed for RTCP~~ **(REMOVED)**
6. Round up the sum to nearest integer kbps to determine b=AS bandwidth

For SDPs with multiple codecs/configurations, the b=AS is set to the highest calculated bandwidth across all configurations.

### Impact

This alignment ensures consistent bandwidth handling across all codecs in TS 26.114 and removes ambiguity in IVAS codec bandwidth computation. Without this correction, implementations could incorrectly allocate bandwidth for IVAS sessions.