A/330, “Link-Layer Protocol”Approved: 14 April 2026

This standard defines the ATSC Link-Layer Protocol (ALP). ALP corresponds to the data link layer in the OSI 7-layer model. ALP provides a path to deliver IP packets, link layer signaling packets, and MPEG-2 Transport Stream (TS) packets down to the RF Layer and back, after reception. ALP also optimizes the proportion of useful data in the ATSC 3.0 Physical Layer by means of efficient encapsulation and overhead reduction mechanisms for IP and MPEG-2 TS transport. ALP provides extensible headroom for future use.

Download current version: A/330:2026-04, “Link-Layer Protocol”, 14 April 2026. This version of the Standard is normatively referenced in A/300:2026-04.

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 documents are listed by date, with the most recent first.

2025

Download A/330:2025-07, “Link-Layer Protocol”, 17 July 2025. This version of the Standard is normatively referenced in A/300:2025-07.

2024

Download A/330:2024-04, “Link-Layer Protocol”, 3 April 2024. This version of the Standard is normatively referenced in A/300:2024-04.

2023

Download A/330:2023-03, “Link-Layer Protocol”, 28 March 2023. This version of the Standard is normatively referenced in A/300:2023-03.

2022

Download A/330:2022-03, “Link-Layer Protocol”, 31 March 2022. This version of the Standard is normatively referenced in A/300:2022-04.

2019

Download A/330:2019, “Link-Layer Protocol”, approved 3 May 2019. This version of the Standard is normatively referenced in A/300:2019, A/300:2020, and A/300:2021.