On Tue, Oct 19, 2010 at 1:04 AM, Manjunath Doddavenkatappa <dodda...@comp.nus.edu.sg> wrote: > > Dear All, > > We are not able to figure out a reason why ETX values in CTP increases as > wake-up interval of the LPL (BoXMaC-One) increases. We have a simple setup > of a sender and a root node placed adjacent to each other. Nodes use > maximum power of 0 dBm. > > 1) We are using IPI of 15s. We repeated the experiment at three > different places with sevral runs runs at every location. Different > wake-up intervals were tried back-to-back so that temporal variations are > minimized. We used wake-up intervals of 10, 20, 40, 100, and 1000 (ms). > > 2) We also used "LPL.setRemoteWakeupInterval(&packet, WAKEUP_INTERVAL + > 100)" but without any luck. > > 3) Our debug messages show that CTP's RetxmitTimer being fired quite a > few times before sucessfully transmitting every packet. > > 4) I first thought that the loss of data packets in the BoXMAC's > preamble could be the reason, but looking into the LPL code, I understand > that preamble packet losses are not fed into the Link Estimator. > > 5) In some experimental runs, particularly when the wake-up interval > is 1000ms, no packet go-through. Requires a hard reboot. > > 6) Searching the archieves for "CTP and LPL on tmote", I found that > similar problem being discussed sometime in Dec 2008. The discussion > suggests quite a few number of changes. > http://mail.millennium.berkeley.edu/pipermail/tinyos-devel/2008-December/003510.html
We should debug this. Do you also observe loss in delivery ratio along with high ETX values? - om_p _______________________________________________ Tinyos-help mailing list Tinyos-help@millennium.berkeley.edu https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
