56 kbps modems

[Asgaard <asgaard@Cor.sos.sll.se>]

>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?

Asgaard