56 kbps modems

[Enzo Michelangeli]

On Fri, 13 Sep 1996, Asgaard wrote:

> >U.S. Robotics and Rockwell International are planning new modems with
> >speeds up to 56 kbps a second, almost double the speed of the fastest
> >rate now available.  The new devices should be available by the end of
> >the year, although their top speed initially may be less than 56 kbps.
> >(Wall Street Journal 12 Sep 96 B11)
> 
> People who seemed to know used to say that 'the Shannon limit'
> set an absolute upper limit around 40 kbps. Has Shannon been
> proven wrong, or what?

Well, it all depends on the signal-to-noise ratio. Also, if the noise is
not white gaussian the situation can be even better.

Enzo