ATSC Technology Group 3 has approved S44-2-002r6, B2X System Discovery and Signaling, as a Candidate Standard. The document specifies the bootstrap structure that lets a device find and connect to a future Broadcast-to-Everything physical-layer waveform.
B2X is intended to let broadcast and mobile systems work together, combining one-to-many delivery efficiency with connected devices and networks. The discovery layer is designed for B2X virtual frames and endpoints operating in both broadcast and International Mobile Telecommunications spectrum.
Candidate Standard status matters because the specification is now available to ATSC members and non-members for evaluation, implementation work and feedback. It is an engineering review stage, not a declaration that consumer services or interoperable receivers are ready for deployment.
The public review closes at the end of June 2027. Other B2X standards are still needed to constrain or extend the bootstrap, and the announcement provides no receiver roadmap, field-trial results, spectrum plan or commercial launch date.
