[W/K] :: Carrierless Amplitude/Phase Modulation

  Carrierless Amplitude/Phase Modulation
       
           (CAP) A design of Asymmetric Digital
          Subscriber Line transceiver developed by Bell Labs.  CAP
          was the first ADSL design to be commercially deployed and, as
          of August 1996, was installed on more lines than any other.
       
          CAP is a variation of Quadrature Amplitude Modulation, the
          modulation used by most existing modems in 1997.  With CAP,
          the three channels ({POTS, downstream data and upstream data)
          are supported by splitting the frequency spectrum.  Voice
          occupies the standard 0-4 Khz frequency band, followed by the
          upstream channel and the high-speed downstream channel.
       
          (1997-10-08)