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RE: ISM interference on 2401 MHz



At 05:42 PM 3/27/02 +1100, Tony Langdon wrote:
>As I'm looking at playing with 802.11 gear myself in the very near future,
>interference management will be an issue I'll be taking a keen interest in
>(QRMing myself isn't exactly what I want to achieve ;) ).  But whatever
>Ilearn out of it will also be good for advising other users of both the
>amateur bands and 802.11 gear.

Out-of-the-box, ALL 802.11b Access Points I've seen are set for channel 
one.  The FCC specifies that the middle channels be used for point-to-point 
links.  The noise from these devices is just so low to be of any serious 
concern, UNLESS you have a point to point with your antenna in the path, or 
a pirate running too much power pops up in your neighborhood.

Some of the spread spectrum phones on the other hand have been reported on 
this reflector to be terrible noise sources.  That is the problem; an 
intentional radiator at these frequencies can take many forms.

Here in the US, and in Europe, 802.11 devices can use frequencies between 
2.412GHz and 2.472GHz.  The cordless phones work in the same "ISM" 
bands.  Not ALL the new phones are spread spectrum, and I believe those are 
the ones about which we're hearing complaints. They seek to find a clear 
frequency, and use older analog technology fir the voice.  All of the 
spread spectrum devices should just raise the noise floor, and not be 
individually discernable as a coherent signal.

73, Mike kf4fdj

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