This document describes the emission system for ATSC Direct-to-Home (DTH) Satellite
Broadcast System. This specification defines extensions to audio, video, transport, and PSIP
subsystems as defined in ATSC Standards A/53B and A/65A. The emission system defined in
this document includes carriage of data broadcasting as defined in ATSC Standard A/90 without
requiring extensions. Furthermore, transmission and conditional access subsystems are not
defined, allowing service providers to use existing subsystems.