Re: getting good range .. - ditching USB wireless adaptor. What PCI one?



Jeff Liebermann <jeffl@xxxxxxxxxxxxxxxxxxxxxx> hath wroth:

Perhaps I'll get it right on the 3rd try. (At home today with a fever
and mild cold. Brain is currently somewhat malfunctional).

Duh. I forgot that Netstumbler does its probe requests at the slowest
speed (1Mbit/sec). Therefore, the wireless speeds do not enter into
the puzzle when using Netstumbler. However, if you are looking at the
SNR reported by the wireless client, it should match the table plus
about 20dB. The way the access point operates is to adjust the speed
so that the error rate is reasonable.

So far, that's correct. The access point adjusts the speed so that
the *error rate* is constant, not the SNR. The SNR will vary with the
connection speed.

I'm not sure of the exact
target value, but I think 20dB is about right.

I'm not sure of the exact target value, but I think a BER of about
1*10^6 is about right.

If the error rate
creeps up, then the access point slows down the wireless speed to
compensate.

Therefore, with the access point speed set to "auto", you
should always see about 20dB or better SNR.

Therefore, with the access point speed set to "auto", you should
always see 6dB to perhaps 40dB or better SNR depending on wireless
speed.

I guess about 20dB would be a good minimum SNR for 1Mbit/sec with
Netstumbler.

--
Jeff Liebermann jeffl@xxxxxxxxxxxxxxxxxxxxxx
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
.