Overview
A liaison statement (LS) is a formal message exchanged between standards groups. In the tables below, Out means a document that 5G-MAG sent to the body, and In means a reply or document that 5G-MAG received. Where a note follows an entry (for example "withdrawn", "approved", "postponed", "revised into ..."), it records the current status of that document or the reply relationship between an outgoing item and the incoming response it triggered.
The tables are grouped by standards body (3GPP, MPEG, ETSI MEC) and listed newest first. Each link downloads the document (a ZIP or office file) from the relevant document server.
3GPP: Incoming / Outgoing LS and Inputs
| Year | In/Out | Meeting | Title |
|---|---|---|---|
| 2026 | Out | 3GPP PCG#57 | 5G-MAG: From 3GPP Specifications to Running Code, and Bridging Standards and Deployments Two slide decks to the 3GPP PCG: news from 5G-MAG on 6G and the AI traffic testbed, avatar calls and SWAP, Advanced Media Delivery (CMCD, QoE reporting, CMMF), MBS, 5G Broadcast and its PlugFest, and the 2026 issue and liaison feedback loop; and an overview of 5G-MAG's scope, projects and ways to join. |
| 2026 | In | 3GPP CT3#148 | Reply LS on High-level design and service APIs for MBS User Service Announcements (CT3 reply to SA4 and 5G-MAG) CT3 confirms that every issue raised on MBS User Service Announcements is fixed, by CR#0086 to TS 29.580. |
| 2026 | In | 3GPP CT4#135 | Reply LS on High-level design and service APIs for MBS User Service Announcements (CT4 draft reply, postponed) Draft CT4 reply, not yet approved: CT4 agreed CRs to TS 29.581 on the User Service Announcement issues. Registered as: C4-262311 CT4#135 · C4-262052 CT4#135 (draft) |
| 2026 | Out | 3GPP SA4#136 | 5G-MAG’s Support to 3GPP Study Items and Work Items Update to SA4 on 5G-MAG's software projects, testbeds, the March 2026 energy-consumption workshop and new leadership; invites 3GPP members to contribute. |
| 2026 | In | 3GPP SA4#135-bis-e | Reply LS on High-level design and service APIs for MBS User Service Announcements (SA4 reply to 5G-MAG, CT3 and CT4) SA4 agreed Rel-17/18/19 CRs to TS 26.502 fixing all six issues raised, and asks CT3 and CT4 for matching stage-3 CRs. Registered as: S4-260734 SA4#135-bis-e · C3-262022 CT3#147 · C4-262245 CT4#135 · C3-263024 CT3#148 |
| 2026 | Out | 3GPP SA4#135-bis-e | High-level design and service APIs for MBS User Service Announcements Reports six issues found while implementing MBS User Service Announcements; asks for CRs to TS 26.502, TS 29.580 and TS 29.581. Registered as: S4-260708 SA4#135-bis-e · C3-261386 CT3#146 · C4-261260 CT4#134 · C3-262023 CT3#147 · C4-262234 CT4#135 · S4-260902 SA4#136 (withdrawn) · C3-263027 CT3#148 |
| 2026 | In | 3GPP CT3#146 | LS Reply on Service APIs for MBS User Services (CT3 reply to 5G-MAG) CT3 agreed seven CRs (six to TS 29.580, one to TS 29.522) fixing the remaining issues, in Rel-18 as 5G-MAG requested. Registered as: C3-261579 CT3#146 · C4-262238 CT4#135 · S4-260894 SA4#136 |
| 2026 | Out | 3GPP CT3#146 | LS Reply on Service APIs for MBS User Services Answers CT3's question on object acquisition identifiers and asks that the Rel-19 fixes to TS 29.580 also apply to Rel-18. Registered as: C3-261385 CT3#146 · C4-261261 CT4#134 · S4-260707 SA4#135-bis-e · S4-260903 SA4#136 |
| 2026 | In | 3GPP CT4#133 | Reply LS on Service APIs for MBS User Services (CT4 reply to 5G-MAG) CT4 agreed CRs 0057, 0058 and 0059 to TS 29.581 on the MBS User Services API issues. Registered as: C4-260367 CT4#133 · C3-261019 CT3#146 · S4-260663 SA4#135-bis-e |
| 2026 | In | 3GPP CT3#145 | LS Reply on Service APIs for MBS User Services (CT3 reply to 5G-MAG) CT3 fixed three of the four issues with Rel-19 CRs to TS 29.580 and asks for more justification on object acquisition identifiers. Registered as: C3-260506 CT3#145 · C4-261021 CT4#134 · S4-260660 SA4#135-bis-e |
| 2025 | Out | 3GPP SA4#134 | LS on Service APIs for MBS User Services Reports issues in TS 29.580 and TS 29.581 found while implementing MBS User Services; asks CT3 and CT4 for corrections in Rel-17 to Rel-19. Registered as: S4-251689 SA4#134 · C3-255041 CT3#144 · C4-255251 CT4#132 · C3-260334 CT3#145 · C4-260051 CT4#133 |
| 2025 | Out | 3GPP SA4 Video AHG post 132 | [FS_Beyond2D] Creation of a 5G-MAG repository Philips and 5G-MAG propose a 5G-MAG repository for FS_Beyond2D evaluation scripts, to be referenced from TR 26.956. |
| 2025 | Out | 3GPP PCG#54 | 5G-MAG MRP Report: Update on 5G-MAG’s Work Update to the 3GPP PCG on 5G-MAG's role, standards highlights, 6G workshop participation and software tools. |
| 2025 | Out | 3GPP SA4#131 | [DEMOS] Reference Tools: Demonstrators at SA4#131 Meeting Slides on the Reference Tools demos at SA4#131: 5G Media Streaming, 5G Broadcast and hybrid services, XR media and the V3C platform. |
| 2025 | Out | 3GPP SA4 MBS AHG post 130 | Input from 5G-MAG to 3GPP SA4: 5G-MAG Exchange, 9 January 2025 Slides for the January 2025 SA4 exchange: 5G-MAG's work areas and Reference Tools projects. |
| 2024 | Out | 3GPP SA4#130, SA4#131 | LS on uplink media delivery features for 5GMSu and RTC (postponed at SA4#130 as S4-242052, noted at SA4#131) Shares 5G-MAG's uplink media delivery report and the gaps found (network assistance, QoE and consumption reporting, multipath) for SA4 to consider. |
| 2024 | Out | 3GPP SA4 MBS AHG post 129-e | LS on 5G-MAG INSIGHTS, Reference Tools and resolution of issues in 3GPP media delivery specifications (also registered as S4-241819 at SA4#130) Informs SA4 about the INSIGHTS conference at IBC 2024, topics of interest to SA4 and new Reference Tools releases. |
| 2024 | Out | 3GPP SA4 MBS AHG post 127-bis-e | 5G-MAG Views on FS_AMD_Advanced Media Delivery Workshop slides on the status of the Reference Tools and 5G-MAG's views on the FS_AMD work topics. |
| 2024 | Out | 3GPP RAN#105 | LS on 5G-MAG activities on LTE-based 5G Terrestrial Broadcast and ETSI TS 103 720 Informs RAN that 5G-MAG will revise ETSI TS 103 720, collecting issues and new requirements, including time-frequency interleaving, on GitHub. |
| 2024 | Out | 3GPP SA1#107 | LS on 5G-MAG Work on NTN for Media Distribution: Devices, services, communication mechanisms and deployment models Informs SA1 of 5G-MAG's first report on NTN for media distribution (devices, services, delivery, deployment models) and a follow-up report. |
| 2024 | Out | 3GPP SA4#127 | Progress on Reference Tools Projects January'24 Progress on the Reference Tools projects (5GMS, 5G Core, 5G Broadcast, MBS, new XR and AI/ML projects); invites feedback. |
| 2023 | Out | 3GPP RAN#102 | 5G-MAG Report on Time and Frequency Interleaving for 3GPP broadcast services Report finding that time-frequency interleaving reuses existing broadcast functions and improves performance; points to a Rel-19 WID proposal. |
| 2023 | Out | 3GPP SA4#122 | On ETSI TS 103 720 Second Version Informs SA4 that draft ETSI TS 103 720 v1.1.18 is stable and asks for MBMS feature codes for 5G Broadcast receiver categories. |
| 2022 | In | 3GPP SA4#121 | Reply LS: Clarification and fixes to 3GPP TS 26.512 SA4 agreed the Rel-16 and Rel-17 CRs to TS 26.512 and accepted regular joint sessions with 5G-MAG between SA4 meetings. |
| 2022 | Out | 3GPP SA4#121 | Clarification and fixes to 3GPP TS 26.512 Reports issues in TS 26.512 found while implementing the 5GMS AF and AS, with fixes proposed in CR0027 and CR0028. |
| 2022 | Out | 3GPP SA4#120-e | 5G-MAG Target 2023 - Reference Tools for 5G-based media services Informs SA4 that 5G-MAG is defining its 2023 Reference Tools roadmap; invites 3GPP members to take part. |
| 2021 | Out | 3GPP TSG RAN#91-e | WID on new bands and bandwidth allocation for LTE-based 5G terrestrial broadcast Supports RP-210127 adding 6, 7 and 8 MHz channel bandwidths to LTE-based 5G Terrestrial Broadcast in Rel-17. |
MPEG: Incoming / Outgoing LS and Inputs
These are inputs to MPEG (Moving Picture Experts Group), organised under ISO/IEC JTC 1/SC 29. The meeting column names the SC 29 working group that received each contribution (for example WG 3, WG 4 and WG 7, which cover different parts of the MPEG immersive and coding work).
| Year | In/Out | Meeting | Title |
|---|---|---|---|
| 2025 | Out | MPEG ISO/IEC JTC 1/SC 29/WG 3 | m74566 - [SD] XR and MPEG-I in Reference Tools Update since MPEG#151 on the XR tools based on MPEG-I Scene Description; shares test assets and asks for feedback. |
| 2025 | Out | MPEG ISO/IEC JTC 1/SC 29/WG 4 | m73733 - V3C and Haptic Immersive platform release on 5G-MAG reference tools (MIV) Release v1.0 of the InterDigital and Philips immersive platform for V3C and haptics, now part of the Reference Tools. |
| 2025 | Out | MPEG ISO/IEC JTC 1/SC 29/WG 7 | m73724 - V3C and Haptic Immersive platform release on 5G-MAG reference tools (V-PCC and Haptics) Same release of the V3C and haptics immersive platform, submitted to WG 7. |
| 2025 | Out | MPEG ISO/IEC JTC 1/SC 29/WG 3 | m73539 - [SD] XR and MPEG-I in Reference Tools Update since MPEG#150 on the XR tools; proposes using them for example workflows and test content. |
| 2025 | Out | MPEG ISO/IEC JTC 1/SC 29/WG 3 | m72702 - [SD] XR and MPEG-I in Reference Tools Update since MPEG#149 on the XR tools; proposes using them for example workflows and test content. |
| 2025 | Out | MPEG ISO/IEC JTC 1/SC 29/WG 3 | m71455 - [SD] XR and MPEG-I in Reference Tools Update since MPEG#148 on the XR tools; announces a 5G-MAG demo at MPEG#149. |
| 2024 | Out | MPEG ISO/IEC JTC 1/SC 29/WG 3 | m70269 - [SD] XR and MPEG-I in Reference Tools Update since MPEG#147; proposes adding the XR tools to TR 23090-24 as example workflows. |
| 2024 | Out | MPEG ISO/IEC JTC 1/SC 29/WG 3 | m69262 - [SD] XR and MPEG-I in Reference Tools Update since MPEG#146; proposes adding the XR tools to TR 23090-24 as example workflows. |
| 2024 | Out | MPEG ISO/IEC JTC 1/SC 29/WG 3 | m67862 - [SD] XR and MPEG-I in Reference Tools Public release of the XR tools, progress on explainers, and 5G-MAG's planned 2024 tasks. |
| 2024 | Out | MPEG ISO/IEC JTC 1/SC 29/WG 3 | m66555 - [SD] XR and MPEG-I in Reference Tools Introduces 5G-MAG's MPEG-I Scene Description libraries, lists missing pieces and invites contributions. |
ETSI MEC (Multi-access Edge Computing)
| Year | In/Out | Meeting | Title |
|---|---|---|---|
| 2024 | Out | MEC043 | Media industry segment |
| 2024 | Out | MEC043 | MEC043 UC on Electronic news gathering |