The MPEG Data Stream - Digital Video and Audio Broadcasting Technology - page 66

BAT

PID=0x11;

Table_ID=0x4A;

Repetition time:
25ms …10s

Bouquet_ID;
Version Management;

Section_length

Bouquet_descriptors_length

Bouquet
descriptors
loop

for i=0 i<N i++

Descriptor();

Transport_stream_loop_length

for i=0 i<N i++

Transport_stream_ID;
Original_network_ID;
Reserved;

Transport
stream
loop

Transport_descriptors_length

for i=0 i<N i++

Transport
descriptors
loop

Descriptor();

CRC_32

Fig. 3.37. Structure of a Bouquet Association Table (BAT)

A close relative of the service descriptor table is the “bouquet associa-
tion table” (BAT). SDT and BAT have the same PID and differ only in the
table ID. Whereas the SDT describes the program structure of one physical
channel, a BAT describes the program structure of several physical chan-
nels or of a large number of physical channels.
The BAT is thus nothing else than a multi-channel program table. It
provides an overview of all services contained in a group. Program provid-
ers can make use of e.g. an entire bouquet of physical channels if a single
channel is insufficient for transmitting the complete range of programs