On May 11, 2006, at 3:34 AM, Omprakash Gnawali wrote:


I want to share my data from a while back when I was looking at
PRR/LQI/RSSI on MicaZ:
http://enl.usc.edu/~om_p/etxlqirss/

For this particular discussion, I wish I had a plot of LQI/PRR and
RSS/PRR (instead of LQI/PRR and LQI/RSS) to compare with Phil's and
Prabal's data. Nevertheless, my data seems to suggest that RSS has
less variance than LQI especially when the links are not that great.


That sounds right. LQI is very stable when it's at the high end of its range. If there is a very high chip correlation (no chip errors), then you'll see a max LQI with no variation. But I think that detecting these very good, high quality, stable links has never been the hard part of link estimation.

I like the 2D plot of LQI vs. ETX. Are the ETX measures really in terms of 10s of packets? It's hard to get a sense of the density of the distribution, though. That is, while the crosses make it look like LQI is all over the place, it might actually be a very tight distribution, whose peaks aren't easily distinguishable from individual data points. Do you have any plots which show that?

Phil
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