Currently the maps.personaltelco.net data displays a pin point for each AP location. What would it take to display an empirical graph of the power output in order to see what area a particular node covers?
The raw data required comes from a gps receiver and correlated with power
- output readings from a wifi card. This can be recorded
by NetStumbler, dstumbler or kismet. Another approach would be to hack [http://nocat.net/download/wpm wpm] (the wireless power meter) or use linux wireless-tools and gpstrans directly.
<Insert some sample data here>
The data set consists of measurements of at least a signal to noise ratio (or some other measure of AP power output) for each gps coordinate.
The next step is to use this data to produce a rough approximation of AP coverage. One way to do this is outlined at University of Kansas ITTC Wireless Network [http://www.ittc.ku.edu/wlan/procedure.shtml "Visualization"] Project.
- In order to compute the Inverse Distance Weighted
interpolation I plan to use a modified Shepard's Method routine from [http://www.netlib.org/toms/790 Netlib]. The beginning of the file contains a lot of test code so search for PRECISION FUNCTION CS2VAL for relevant comments.