Hi guys, I've seen this problem with TKN15.4. It is possible to synchronize N nodes with TKN15.4 the problem is that they need to start the app at the same time. From my experience I've realized that the problem comes from the *cc2420_tkn154 *(maybe it happens with the default cc2420 implementation as well).
If we have a network with N nodes running and transmitting data between them, when we try to add another node we could have this problem. As far as we have the radio enabled for reception for a long period (Scan period), the cc2420 receives the beacons but data packets as well. Once it detects that the received packet is a beacon, it sets the timestamp, but sometimes the timestamp is wrong, due to the data packets, and then we lost the next beacons. Possible solutions: - Check the *CC2420ReceiveP.nc* and the *m_timestamp_queue. *I guess that the problem should be there. I did some modifications on the * CC2420ReceiveP.nc *to solve this problem, but I haven't test it properly. - If we lost the synchronization, scan again with MLME_SCAN.request(). It is a "fake" solution, because the problem is still there, but for some app it will work. - Start the nodes at the same time. It is not possible in a real deployment. -- Aitor Hernandez KTH | Automatic Control Research engineer Stockholm Phone: +46 (0)704 26 87 99
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