S4-260086 - AI Summary

Procedure for IVAS bandwidth computation

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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:
  5. 16 kbps for IPv4
  6. 24 kbps for IPv6
  7. ~~Add bandwidth needed for RTCP~~ (REMOVED)
  8. 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.

Document Information
TDoc:
S4-260086
Source:
Ericsson LM, Samsung Electronics Co., Ltd, Nokia
Type:
CR
For:
Agreement
Original Document:
View on 3GPP
Title: Procedure for IVAS bandwidth computation
Agenda item: 7.4
Agenda item description: Release 19 and earlier matters
Doc type: CR
For action: Agreement
Secretary remarks: Source modified on 2/3/2026. Original source : Ericsson LM, Samsung Electronics Co., Ltd, Nokia
Release: Rel-19
Specification: 26.114
Version: 19.2.0
Related WIs: IVAS_Codec
CR number: 606.0
CR category: A
Clauses affected: Z.2
CN: True
CR: 606.0
ME: True
Spec: 26.114
Contact: Tomas Jansson Toftgård
Uploaded: 2026-02-03T20:24:30.307000
Contact ID: 72490
Revised to: S4-260319
TDoc Status: revised
Clauses Affected: Z.2
Reservation date: 02/02/2026 09:28:22
Secretary Remarks: Source modified on 2/3/2026. Original source : Ericsson LM, Samsung Electronics Co., Ltd, Nokia
Agenda item sort order: 16