On Tuesday (07/02/2002 at 09:08PM -0500), Matthew S. Hallacy wrote:
> On Tue, Jul 02, 2002 at 04:09:22PM -0500, Chris Elmquist wrote:
> [snip]
> > You get the same behavior often when trying to run a 2.4 GHz cordless
> > phone near your 802.11b stuff.  The phone just knocks the WLAN equipment
> > right to zero... even though they are on different "channels" and use
> > different spreading sequences, they're in the same passband and the
> > poor receiver gets nailed by the nearby transmitter.
> Strangely enough my 2.4ghz phone (made by GE) seems incapable of causing
> interference with my wireless, and the lan doesn't cause any problems
> with my phone (no static whatsoever) the phone has a range of just over 100
> yards, and the Access Point/Phone Base station are only seperated by about
> 10 feet =)

well, I am sure this is an issue where YMMV.  I have had two different
2.4 GHz phones... a Panasonic and a Sony... and both completely wiped
out my 802.11b network whenever the phone(s) were off-hook.  You could
get some improvement with a huge seperation between the handset and the
wireless node but it was IMPOSSIBLE to use the 802.11b LAN in a laptop
while simultaneously talking on the cordless phone.

I could watch the signal meter on the Orinoco client app and
as soon as the phone went off hook, the signal meter went to zero
in a heartbeat.  There was no half-power or partly degraded link...
that baby went to absolute zero instantly.

Before I traded the phone for a 900 MHz model, the best I could do was
to have the AP (an Apple Airport) no more than 8' from the laptop.

I played with channels, 'microwave robustness' and even antenna polarization
and still couldn't get there.

So, I became a big fan of 900 MHz cordless phones :-)

> > Hmm...  move your 802.11b to 5.7 GHz ?  :-)
> Less range, more expensive.

well, I was thinking more along the lines of a transverter (ie, transmit/
receive converter) that would allow you to run 802.11b protocol except
on 5.7 GHz-- rather than 802.11a.  You can buy these... they are used
for backbone hops and point to point links but of course it's
more cost than the straight 802.11b gear.  It would be cheaper and much more
convenient to get a 900 MHz cordless phone :-)

Chris Elmquist   mailto:chrise at pobox.com   http://www.pobox.com/~chrise