On Tue, Apr 15, 2008 at 1:48 AM, Michiel Konstapel <[EMAIL PROTECTED]> wrote: > > > We have found that CTP is sensitive to short bursts of packet loss on > otherwise good radio links (ETX 1.0 to 1.2) and found something that may be > of interest. LinkEstimatorP uses an ALPHA parameter of 2 (actually 0.2) for > decaying its exponential average of eetx: > > void updateEETX(neighbor_table_entry_t *ne, uint16_t newEst) { > > ne->eetx = (ALPHA * ne->eetx + (10 - ALPHA) * newEst)/10; > > } > > > Written as it is, this means it takes 80% of the new estimate and 20% of the > old – is it possible that this was supposed to be the other way around? We > find that a short burst of lost packets will quickly increase ETX to levels > where CTP will select a new parent, which causes excessive beaconing as CTP > resets its beacon interval and other nodes start switching parents as well. >
This was fixed in December to use an alpha of 9. Depending on what version you are using, you might be missing this and other important updates to CTP. In a day or two, there will be a new commit that dramatically reduces the number of beacons. - om_p _______________________________________________ Tinyos-help mailing list Tinyos-help@millennium.berkeley.edu https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help