Source : Free On-Line Dictionary of Computing

Data Over Cable Service Interface Specification
     
         (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.
     
        {CableLabs FAQ (http://www.cablemodem.com/FAQs.html)}.
     
        (2001-07-10)