Andy Middleton wrote:

> Jack and Frank
>
> I've read your book; has been a HELL of ALOt of help! Great stuff!
> However passive repeaters are only mentioned, and my question is this:
> I have an AP at 1km west from my flat, but no direct view. I have a friend's
> flat 50m north and higher up who does see the AP. After trying to calculate
> freespace loss using a passive repeater, for two radio journeys (1km=100dBm,
> 50m=78dBm), it seems I need a signal that is 178dBm stronger than my
> reciever threshold? I am assuming that the repeater will not lose any power
> just to keep things simple, and was thinking of 2 similar 14dB gain yagis
> that theoretically will not add anything only redirect the signal 90� south
> from my friends flat to my flat.
> With this calc., I seem to need a transmitter with more than 93dB power to
> get a signal on a -85dB card! This is obviously not possible with 802.11b!
> Is there anyway around this? Should I use different antenas on the repeater?
> Is repeating at tese low powers only possible with a powered repeater?

Andy - You are correct that the path loss with a passive repeater is equal to
the sum of the free-space path losses over both of the paths. This makes a
passive
repeater not practical at 802.11b power levels. Your best bet is to use a
powered
repeater (one radio that will repeat but cut the bandwidth in half, or one radio

with two wireless cards, or two radios back to back).

jack

>
> Any help would be ideal as I am trying to set up a LAN with a webcam on the
> AP looking out over Santa Cruz.
>
> PS. If the webcam is at the AP, the easiest solution to see it on the WLAN
> would be plugging it into a LAN port in the AP?  Sounds right.
>
> Thanks
>
> Andy, Tenerife

--
Jack Unger, President-Wireless InfoNet ([EMAIL PROTECTED]) 818 227-4220
Vendor-Neutral WISP Training - http://www.ask-wi.com/2002workshops.html
Author - "Deploying License-Free Wireless WANs"
<http://www.ask-wi.com/book.html>


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