[BC] Amateur radio spectrum

[RichardBJohnson at comcast.net]

You don't do it in 40 kHz bandwidth and you know it. You do it
by spreading the spectrum over several GHz. That's what it's
all about. If everybody is using the same technology, they
all get along just fine. It's when you have to protect the
near CW carriers of the FM/TV and VHF Ham bands, that the
problems are created.

As a thought experiment, consider sending ten-thousand
small, but high-sample-rate messages within a coaxial
cable. Each message has been dithered with its own
pseudo-random code so that, a receiver that syncs to
the same pseudo-random code will demodulate it. This
is the channel, which is no longer in the "frequency
domain" like you are used to, but in the digital domain
where the number of channels is dependent upon the
number of pseudo-random words available (a large number).

Now, you have all the stuff playing along fine and
somebody puts a CW carrier on the coax. What happens?
I'll tell you what happens... NOTHING gets through
because it doesn't move out of the way of other user's
sidebands --ever.

Now don't get your Ire up because somebody said that
ham radio, as we know it, is obsolete. When the new
techniques are in wide use, and believe me they eventually
will be, the special-use services such as amateur radio
will probably get a block of addresses to experiment
with --the essential equivalent of the current frequency
bands.

Cheers,
Richard B. Johnson
Book: http://www.AbominableFirebug.com/

----- Original Message -----
From: "Tom Bosscher" <tom at bosscher.org>

    I'm going to ask for the question.....

    What technology, available today, can transfer the contents of a 250 
gig hard drive, in 1 second, using the spectrum taking up by two 
(duplex, using a repeater pair) analog FM channels, approx 40 kHz total?

    I'm real interested to see how to transfer 250 gigs in 1 second in 
40 kHz.

       tom bosscher