Consists of one or more [RF] QAM channels.
Uniquely identified by MPEG PID field (2-bytes)
Information is conveyed to WCM by WDCD (Wideband Downstream Channel Descriptor)
WDCD is transmitted every 2 seconds
WDCD is transmitted on all bundled NB channels associated (in the WB-NB association table) with the WB channel
WCM must re-register if 3consecutive WDCD are missed
