ds1c

1 definition found

ds1c - Free On-line Dictionary of Computing (26 May 2007) :

  DS1C
  
     <communications> A DS level and framing specification for
     digital signals in the North American digital transmission
     hierarchy.  A DS1C signal uses 48 PCM channels and has a
     transmission rate of 3.15 Megabits per second, twice that of
     DS1.
  
     DS1C uses two DS1 signals combined and sent on a 3.152
     megabit per second carrier which allows 64 kilobits per
     second for synchronisation and framing using "pulse stuffing
     ".  The channel 2 signal is logically inverted, and a
     framing bit is stuffed in two out of three code words,
     resulting in 26-bit information units.  The channels are
     interleaved and then scrambled by the addition modulo 2 of
     the signal with the previous bit.  Finally the bit stream is
     combined with a control bit sequence that permits the
     demultiplexor to function by preceding each 52 bits with one
     DS1C framing bit.  A series of 24 such 53-bit frames forms a
     1272-bit "M-frame".
  
     (1995-02-07)