A/351, “Techniques for Signaling, Delivery and Synchronization”Approved: 14 April 2026

This document provides recommended practices for the ATSC 3.0 Signaling, Delivery, Synchronization, and Error Protection standard as specified in A/331. The document contains recommendations for broadcasters on the usage of the ROUTE and MMTP protocols and their associated technical capabilities in support of different Service delivery scenarios. In addition, transmission-related guidelines are provided on a variety of other functions and mechanisms as defined in A/331 including Service and audio language signaling, advanced emergency information, Staggercast, and the mapping between Service delivery and lower layer transport.

Download current version: A/351:2026-04, “Techniques for Signaling, Delivery, and Synchronization”, 14 April 2026.

Previous Versions

There are multiple versions of this document. Please be sure to download the desired version. For amendments, the text includes a list of changes, the rationale for the changes, and compatibility considerations. The following are listed by date, with the most recent first.

2025

Download A/351:2025-07, “Techniques for Signaling, Delivery, and Synchronization”, 17 July 2025.

2024

Download A/351:2024-04, “Techniques for Signaling, Delivery, and Synchronization”, 3 April 2024.

2023

Download A/351:2023-03, “Techniques for Signaling, Delivery, and Synchronization”, 28 March 2023.

2022

Download A/351:2022-03, “Techniques for Signaling, Delivery, and Synchronization”, 31 March 2022.

2021

Download A/351:2021, “Techniques for Signaling, Delivery, and Synchronization”, 15 February 2021. This document is a rollup of Amendments No. 1 and No. 2 to A/351:2019.

2019

Download A/351:2019, “Techniques for Signaling, Delivery, and Synchronization”, approved 28 August 2019.

Download A/351:2019 Amendment No. 1, “appContextID”, approved 20 January 2020.

Download A/351:2019 Amendment No. 2, “appContextID”, approved 15 February 2021.