资料来源 : Free On-Line Dictionary of Computing

E-carrier system
     
         A series of {digital} transmission formats
        promulgated by the {ITU} and used outside of North America and
        Japan.
     
        The basic unit of the E-carrier system is the {DS0}, which has
        a transmission rate of 64 Kbps, and is commonly used for one
        {voice circuit}.  The {E1} format consists of 32 DS0 channels,
        for a total capacity of 2.048 Mbps.  {E2}, {E3}, {E4}, and
        {E5} circuits carry multiple E1 channels multiplexed,
        resulting in transmission rates of up to 565.148 Mbps.
     
        The E-carrier system is similar to, and compatible with, the
        {T-carrier system} used in North America, but has higher
        capacity since it uses {out-of-band signaling} in contrast to
        the {in-band signaling} or {bit-robbing} used in the T-system.
     
        (2000-03-10)