Hi All, I am facing packet loss problem with CTP in TinyOS 2.0(using the release 2.0.2) on telosb. Initially, I faced this in my modified-MultiHopOscilloscope code where I was accepting multiple message types and forwarding them to the Root node, but since I had changed some code, included a queue, added some functionality etc, it was difficult to understand whether the problem is with my addition in code or MultiHopOscilloscope. I saw packet loss in above case in different network settingto the extent(worse case) that I dont receive messages from some nodes/all nodes for even an hour and then start receiving again. To trace out the problem, I started with simple apps/MultiHopOscilloscope(negligible changes to make it compatible with my Java GUI app) application on 10 nodes (interval = 5 sec), since it has been tested exhaustively. All the nodes can reach the Root node directly and they are kept very close to each other. I saw a strange behaviour using SerialForwarder - When the application is running for some hours, sometimes, i dont receive messages from a particular node for some minutes and then it comes back again. Its reproduced many times.
Has anybody seen this kind of behaviour ? Since MHO is stable, so there should be a problem at my end but I am not able to find where. Since the nodes can reach root node directly, they will send message only to it or also other nodes ? Can there be a problem with root node sending of messages on UART or some other queue overflow ? I am using baud rate of 115200. Next, I will try to use printf to understand at which level the problem is. As i read, the reliability of CTP should be 99.9% at low traffic rate, but the 0.1% messages that are lost, are lost periodically or there is a possibility that they can be lost in chunks of messages ? and what will be high traffic rate ? My application is totally based on Node visibility/absence and if I loose some Nodes falsely for some minutes, its a big problem. If somebody has any suggestions, they are welcome. Best Regards, G -- --------------------------------------------------------------------------------------------------------------------- To accomplish great things, we must not only act, but also dream; not only plan, but also believe. - Anatole France _______________________________________________ Tinyos-help mailing list [email protected] https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
