communications, networking (DOCSIS) ITU-approved interface

requirements for cable modems involved in high-speed data

distribution over a cable television network. DOCSIS

compatible equipment uses a 6 MHz carrier band for

downstream, using 64 and 256 QAM (ITU Annex B), and QPSK

and 16 QAM for upstream, allowing up to 36 and 10 Mb/s,

respectively for downstream and upstream channels.