Thanks Urs for your reply, I don't think if this would be the case, because first of all if this problem was because of XMesh sequence number, this would happen for every mote, while this problem just happened for 7 or 8 motes out of 10. The second point is that after this problem happens to a mote, regardless of the program that I install on that mote afterward (either my own program or XMTS310) and the mote id which I assign to it, the mote can not find the basestation and send the data, so it somehow shows that something happens to the mote's hardware or ....
My own idea was that maybe in some part of my program, I change the transmission power of the mote incidentally and it causes lower sending and receiving power, so the mote can not receive server messages anymore and the sent messages by the mote are not strong enough to receive to the server. Do you think if this can be the case, and is there any way to check it? BTW if you think my problem is still ambiguous, I can redescribe it in a better (and probably longer :D) way. Mohammad 2009/6/12 Urs Hunkeler <[email protected]> > Hi Mohammad, > > After reading your original description of the problem, I think that an > intermediate node (e.g. the basestation) does not realize that the nodes > have been reset. I think that XMesh uses sequence numbers in their packets. > After a node has been reset, maybe it starts over again with the sequence > numbers and the basestation thinks that the transmissions are in fact old > retransmissions and discards them. > > Cheers, > Urs > > > > Mohammad S. Hashemian wrote: > >> Hello again guys, >> >> No reply for this problem? even any thoughts or clues? maybe I wrote it >> too >> long, my guess is the transmission range and communication power of the >> nodes gets less and less by passing time. has anyone faced with such a >> situation ever? does anyone has any thoughts about this? >> BTW I do lots of broadcasting in my program (one at every 6 seconds) can >> this be a reason for the problem? >> >> >> >> 2009/6/5 Mohammad S. Hashemian <[email protected]> >> >> Hi all, >>> >>> I ran into a very weird problem recently. I was using Crossbow MoteWorks >>> framework for writing a program and installing it on some MicaZ motes. >>> The >>> program was sensing some data from MTS310 sensor board and report them to >>> the base station. After writing the code, I picked some new MicaZ motes >>> and >>> installed the program on them, everything was working fine. After one day >>> I >>> had to reset the motes to change their battery, when I turned them on >>> again, >>> most of them (around 80%) couldn't join the network alone, i.e. if I was >>> just turning that mote on alone with server, the mote couldn't find the >>> server, even though they were right next to each other! But when I was >>> picking another fresh new mote and installing my program on it and >>> putting >>> it between the old mote and the server, the old mote could create a >>> two-hop >>> network and send it's data to the server via the new mote! >>> I checked the old motes with XMTS310 program (the one which ships with >>> MoteWorks framework), but the old motes were just collecting the data and >>> sending the packets, but server never could receive those packets from >>> old >>> motes (probably because the wireless transmission power of the old motes >>> were too low that server couldn't receive them!) >>> >>> Does any one have any idea or any clue that what might be the source of >>> this problem? I really appreciate any response. >>> >>> Thanks in advance, >>> Mohammad >>> >> -- Mohammad S. Hashemian Research Scholar/DISCUS Lab Department of Computer Science 254.2 Thorvaldson Building University of Saskatchewan (306)966-1947
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