On Aug 9, 2009, at 1:55 PM, Razvan Musaloiu-E. wrote: > Hi! > > In case some people interested in this are not reading tinyos-help. :P > > -- > Razvan ME > > ---------- Forwarded message ---------- > Date: Fri, 7 Aug 2009 16:27:27 -0400 (EDT) > From: Razvan Musaloiu-E. <[email protected]> > To: [email protected] > Subject: [Tinyos-help] significant changes to the PRR/SNR curve in > TOSSIM > > Hi! > > About 2 months ago, a commit [1] to CpmModelC.nc that eliminates the > problem of receiving packets (non-zero PRR) for negative SNR also > made a > significant change to the hardcoded PRR/SNR curve. This was not > adequately > documented in the commit message and many people might not be aware of > this. Here is a plot that shows the differences: > http://bit.ly/znrwQ > > The points represent the data collected by Yin Chen, a member of our > lab. > In his tests the noise level was controlled by using a noise > generator so > it covers a wide range. Similar data was also reported by the > following > paper: > http://portal.acm.org/citation.cfm?id=1460427 > > So there are reasons to believe that even the current curve we have > in the > tree is not the most accurate one. Caution is advised! :-) > > [1] > http://hinrg.cs.jhu.edu/git/?p=tinyos-2.x.git;a=commit;h=afe96d7e2a3747bba450e3db88a89569a0ba53b6 >
I'll note that the new curve is closer than the old curve. If you have a better curve to propose, I'm sure SunHee would be happy to test with it. Phil _______________________________________________ Tinyos-help mailing list [email protected] https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
