Channel usage

[Alex Satrapa]

On Thursday, December 6, 2001, at 03:38 , Bob Edwards wrote:
> Just to clarify my situation, I am not actually co-locating the APs,
> just spreading more and more around our building. ...

> It's a bit like the four-colour map-colouring problem - only now I
> am working in 3 dimensions (3 storey building with APs on each level).

My (naive) approach would be to base channel proximity on inverse 
physical proximity.

So if you have "East/West" and "Up/Down" as your axes of the building, 
place them as such:
1  E/U
5  W/D
9  E/D
13 W/U

Thus the chance of interference is minimised by the fact that you've got 
more concrete and steel in the way.

Where the cartographer has four fixed colours, you have the option of 
changing your ink to be invisible from certain directions - one article 
I've read about wireless hubs suggest such putting a specially designed 
antenna on the hub which flattens its signal out (so rather than being a 
dougnut it's a pita bread), then reduce the signal strength.

The article - "Antennas Enhance WLAN Security" -  
http://www.byte.com/documents/s=1422/byt20010926s0002/1001_marshall.html

This would indicate that using vertical polarisation is especially 
useful for the instance where you're connecting laptops through these 
things.

HTH
HAND