wanted: wireless magic tricks

Fri Aug 17 01:23:34 UTC 2001

On Thu, Aug 16, 2001 at 12:53:08PM -0400, Greg Maxwell wrote:
> 
> On Thu, 16 Aug 2001, Dennis Dayman wrote:
> 
> > In this 20 miles does he have Line of Sight (LOS)?  A wireless protocol,
> > Mag Grid antenna, and an .5-1.0 WATT amplifier could do the trick.  But
> > he needs to watch his DB levels so if he does use the 1.0 WATT AMP he
> > doesn't go over the un-licensed FCC spectrum.
> 
> You're not going to do a high bandwidth link 20 miles in ISM with a
> permitted EIRP (I think 4watts).
> 
> That doesn't seem to stop a lot of people from putting a 20+db gain
> antenna on a 1watt input for this stuff, but 50 watts EIRP isn't anywhere
> near legal.

I beg to differ, at my last employer we used BreezeCom 802.11b equipment for
links around 20-25 miles using 24 dbi grid mesh antennas, two antennas on each
end, approximately 150-200 feet in the air (usually on water towers, or grain 
elevators, fun climbing when I wanted out of the office..) all within legal 
limits. (The sheriff's dept claimed we were causing interference and had their RF
engineer come check out all of the equipment near theirs, calculated output power, 
etc, it turned out to be something else)

Of course, this is 802.11b, 11mbit claimed, 6mbit real under perfect conditions, 
I prefer the 5.2/5.8ghz band myself seeing how my cordless phone, X-10, and everyone
else is now marketing their merchandise in the 'totally unused 2.4ghz unlicensed band'

					Matthew S. Hallacy