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Wireless

Here's a collection of snapshot of wireless parameters taken several places. There are four of parameters I have been into. They are Link, Level,Noise, and misc(discarded packets) from wireless technology. Link has to do with how good the reception is (proportional to the percentage of correctly received packets), level is related to how strong the signal is (in dBm), noise is how "noisy" your signal is and the "misc" shows the number of discarded packets in a way. Those have been measured as a function of time (three minutes each).

First one is from my office at SLAC as shown below. Link stays at 50 most of the time, and so are at 200, 150, and 10 for level, noise and misc., respectively.

No idea what they meant? So did I. So I went ahead and measured them at my place at home which had a commecial wireless being transmitted from unidentified neighborhood (I did not pay for it... so the signal is very weak and unstable :-)).

As you can see, significantly weak link vaules were obtained (even zero for some period!) but level and noise remain at the same order of magnitude. And there are many missed packe ts. No $$$, no gain. As a next step, I took a field trip to the prestigious Stanford Univ. campus (near to Meyer Library) and measured them. See the below.

Stanford is as good as SLAC for all except "link". It is about 20% reduction but given the fact that I have not gone through wvlan_cs.c, I have no idea how seriously I want to take those numbers?

I must mention here one thing. Above plots were from gtk + Belle daq stuff modified by myself. All data were taken with my laptop (Dell Latitude X200 with pcmcia WaveLan device.) Some of Belle people recognize the smell of the daq gui of it if you are selective. I have a plan to move from gtk to Qt in near (?) future as soon as I get rid of this ZPD project. If you want to know what I am talking about here, a good start might be /proc/net/wireless. I am also evolving myself rapidly (not really)...