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Re: [LUG] wireless musings



On Saturday 26 July 2003 01:20, you wrote:
> So a directional aerial won't actually boost your transmit power, if you
> are to stay within the law, but will allow you a stronger receive signal,
> yeah?

No. As wifi is a two-way signal, a decent antenna will boost your signal 
20+dB. Thats a 100-fold increase on the original signal.

You transmit at 100mW, you lose some in the cable to the ariel, the air 
between ariels, and the cable from the Rx ariel. You gain because of 
ampliefiers and ariels. Typically you transmit at 10dB and receive at -80dB. 
The total loss, of cable and air combined with the total gain of amps 
and ariels, must be less then that 90dB difference. 

> I've seen some impressive statistics quoted using normal equipment strapped
> to an old satellite dish, I might try that some day... although I think
> it's still pretty much "line of sight". :-(

2.4GHz cant go through objects, so while LOS is possible, using multipath, 
its not really probable. With full LOS you should push 10 miles by only 
breaching the 100mw "by a little bit". 

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