This document specifies the communication protocol between an ATSC 3.0 primary device and an ATSC 3.0 companion device. In this context, the primary device is the primary receiver and is used to present the primary content. The companion device communicates with the primary device to present related, supplementary content, or even the same content as that being presented on the primary device. Examples of primary devices include television sets, set-top/converter boxes, and mobile devices that are capable of receiving ATSC 3.0 services. Examples of companion devices are laptops, tablets, and smartphones.
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.
Download A/338:2017, “Companion Device”, approved 17 April 2017. This version is referenced by A/300:2019.
Download A/338:2019 “Companion Device”, approved 2 October 2019. This version is referenced by A/300:2020.
Download A/338:2019 Amendment No. 1, “CD Event Stream API”, approved 21 January 2020.
Download A/338:2021, “Companion Device”, approved 19 February 2021. This version is referenced by A/300:2021.
Note that a revision to A/338:2021 is currently at Candidate Standard status. That document can be found on the Candidate Standards page of the ATSC web site.
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Advanced Television Systems Committee, Inc.
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The Advanced Television Systems Committee, Inc., is an international, non-profit organization developing voluntary standards and recommended practices for digital terrestrial broadcasting. ATSC member organizations represent the broadcast, broadcast equipment, motion picture, consumer electronics, computer, cable, satellite, and semiconductor industries. ATSC also develops digital terrestrial broadcasting implementation strategies and supports educational activities on ATSC standards.