It could be environment-dependent multipath fading. If you haven't read the following paper, it might provide you with some useful background information:
http://www.icsi.berkeley.edu/~zhao/papers/sensys03.pdf Look at Fig 13 -15, for example, which demonstrate exactly the behavior you describe. - Prabal On 2/26/06, Lima GANSE Kenneth <[EMAIL PROTECTED]> wrote: > > > Hi all, > > I know some stuff has been written on this with mica2 on the help archive, > but can someone help explain this. I have gathered receiver RSSI readings > between itself and a transmitter at different distances in 20cm increments. > I am trying to see if these values can give me an approximate(of course not > precise) value of the distance that lie between them. I am using Micaz and > after several tests, have finally set my transmitter power to 31 (0 dBm). > > I was expecting that although the values(Msg->strength) arent going to > reduce in a linear form as i move the receiver 20cm away, it will > nevertheless reduce each time i do so. Unfortunately this stopped at some > point and the value started increasing. Does anyone have any experience on > this, or has a hint on why this is happening? > > Best regards > > Kenneth > _______________________________________________ > Tinyos-help mailing list > [email protected] > https://mail.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help > > > _______________________________________________ Tinyos-help mailing list [email protected] https://mail.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
