"Dana H. Myers" wrote in message
...
Marty Albert wrote:
As I recall, at 23 cm and 80 Mbps we had an effective bandwidth of around
100 KHz on the "final" design... That design incorporated TDM, limited
SS,
and WDM of the signals.

What exactly does this all mean?

Passing 80,000,000 bits/sec in 100,000Hz of bandwidth sounds
pretty fantastic - to the extent that makes me question the
validity of the measurements.

This in 100 Hz of bandwidth we can obtain 80 Kbps.
Shannon twirling in his grave.

Today, we could use TDM, WDM, SDM, high-end SS, and a few other tricks
and,
assuming a target data-rate of 100 Mbps, get the on air bandwidth down to
around 50-75 KHz, maybe even a little less.

Whoa. Hold on. Help me understand what units and methods
of measurement you're using. Right now, you're off by several
decimal places in even the most generous way.

Lost a decimal point for sure.

BTW ... why does everyone always mention 1200 baud?
Doesn't everyone use at least 9600 for local links, and
PACTOR II / III on HF?

Think I have a 1200 baud TNC around here ... yeah there it is
over in that cabinet. Big black box, says TAPR TNC-1 on it.

--

... Hank

http://home.earthlink.net/~horedson
http://home.earthlink.net/~w0rli