Hi, In the LPL stack, in the PowerCycleP file:
I don't understand why it is needed to probe 400 times (MAX_LPL_CCA_CHECKS) the signal strength to detect if there is currently a transmission. The sender on the other side sends continuously, there is just a bit of radio silence between two duplicates. 400 times is like 50ms (according to another post), which is a lot. Finally, if you put a node to sleep 100 ms, then it's actually with the radio on for half of the time (!) Then, if I decrease this MAX_LPL_CCA_CHECKS to 80, then I get about 50-60 percent packet losses. (LPL with receive sleep between 100ms and 300ms). Whereas with the value set to 400, I have a residual 1 % packet loss. Can somebody explain me the reason behind this 400 value? Why is it so large? Why is for example 80 not enough? The nodes are close to each other and send at 0 dbm, so I don't expect the CCA threshold to be an issue. The CC2420 spec says that the RSSI prob is +-6db, but I expect the RSSI to be anyway 12db more than the CCA threshold. That question was already asked in the following post, but remained unanswered: http://mail.millennium.berkeley.edu/pipermail/tinyos-help/2009-February/038272.html Thanks for any help, Best regards, Alban _______________________________________________ Tinyos-help mailing list [email protected] https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
