ATSC M/H Group [EtherGuide Glossary]
An ATSC M/H group is an organizational concept used in ATSC M/H transmission.
The diagram below illustrates the relationships between ATSC M/H Frames, ATSC M/H sub-frames and 8-VSB data frames.
Each 8-VSB data frame spans 624 MPEG-2 packets (938,496 bits). In ATSC M/H usage, each 8-VSB data frame can contain either 72 contiguous MPEG-2 packets (108,288 bits) and 552 contiguous ATSC M/H packets (830,208 bits) or, if no ATSC M/H data is present in a particular data frame, 624 MPEG-2 packets (938,496 bits).
Therefore, there are 12,480 packets totaling 18,769,920 bits in each ATSC M/H frame.
The organization of M/H Ensembles, M/H Groups and M/H Parades can dynamically change from one M/H Frame to the next.