digital XM satellite radio - which codec is are used? 2001-10-07 02:08:17 As some of you may have heard, a new digital satellite radio system has recently launched in selected areas of the US. Starting on Sept-25, XM radio has launched service on "test markets" San Diego and Texas. Somewhat later the service will be launched nationwide in the US.XM radio has launched two satellites called "Rock" and "Roll" into geostationary orbit above the US and covers most of the north American subcontinent. Those two satellites are said to be the highest powered commercial satellites up to date (something like 18 kilowatts of electric power each).Receivers start at about $300 and a monthly subscription fee of close to $10 is required for getting service. 31 of their about 80 programs are commercial free. They claim to broadcast in CD quality.The things that interests me as an enginner is:- what audio codec did they license? AAC? What bitrates?- what digital modulation is used?I am considering getting a portable home/car receiver. Samples of their program can be heard on www.xmradio.com (32kbit WMA).