On Thu, 24 Jul 2008 14:41:36 -0400, Steve Bonine wrote:

There's an article in today's Washington Post

http://preview.tinyurl.com/6ego68

that describes a technology that's under development to provide Interne
t
access using spectrum in the TV channel range. Apparently this scheme
checks for a signal before it uses a specific frequency and switches to

a different one if it detects that the frequency is in use.

I wonder how this will work and play with amateur radio. I remember
when TV channel 2 was established in my home town, effectively shutting

down six meter ham operation because the TV signal was so weak that eve
n
a correctly-operating six-meter rig would create serious TVI for the
fringe reception of channel 2. Decades have passed and this new
technology surely is much less sensitive to adjacent signals than the
TVs of my childhood, but the analogy persists.

I'm not too worried about interference to/from amateur radio.

Users aren't going to recognize overload problems as coming from ham gear
..
The things are simply going to intermittently stop operating and they're
going to blame it on an outage of the ISP's base station. It won't play
your voice out their speakers the way it does with an analog TV set. And
they're never going to get FCC approved unless they know how to confine
their emissions to the TV channel they determined was unused. They're no
t
going to spill over into ham bands.

(at least not the legal ones. The illegal ones will spill even if the FC
C
never approves this technology.)

I'm a lot more worried about it as a TV engineer and semi-rural
over-the-air TV viewer. In early tests these things weren't very good at
determining whether a channel was unused. I can see that becoming a big
problem in semi-rural areas like this, where people might be using roofto
p
antennas to get TV but the Internet devices will probably be on makeshift
indoor aerials.

On the other hand, I'm not holding my breath waiting for someone to build
a base station out here. The technology may well never come to places
rural enough to be in TV fringe reception.