[CUWiN] good news everyone

Aaron Kaplan aaron at lo-res.org
Fri Aug 4 19:47:49 CDT 2006

On Thursday Funkfeuer hat some visits by the "Funkueberwachung" (the
german equivalent of the FCC). They wanted to measure that we really
don't exceed the 100mW EIRP power limit according to austrian and german
law. And if you know german and austrian officials, they really don't
allow for any buffer zone at all.

In the course of this rather unpleasant visit they also measured how
well the RX and TX antenna outputs are separated on the standard linksys
WRT54G(L). The good news: there seems to be 26 dB difference between
antenna A and B !

What does that mean? 
It seems perfectly legal to operate a 24dBi high gain antenna (or even
more!) on the RX side and a normal less powerful antenna on the TX side.
In other words: the linksys does not "talk over" from the TX antenna to
the RX antenna.
This can help us to build better mesh networks. You could also express
this as: "talk quietly, don't shout and listen very intently" In these
setups the total SNR (signal to noise ratio) in the whole network will
probably increase quite nicely. And this is what counts for 802.11a/b/g
For most people this is not a surprise. Nice fact is that the RX/TX
separation actually works (legally) on the Linksys.

best regards,
aaron kaplan.

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