Hi all,

if you intend to test the low-power MAC protocols from WUSTL's UPMA
framework, especially X-MAC, please note that you have to pay attention to
the length of the CCA check's routine. You must set up the
DEFAULT_CCA_LENGTH in
*/opt/tinyos-2.x-contrib/wustl/upma/chips/cc2420/PowerCycleP.nc
*accordingly to the platform you are doing tests with.

By default, the setup is 8ms which corresponds to the maximum gap between
two strobed preambles on TelosB platform. However, on MicaZ platform, I have
observed that this gap roughly ranges from 12ms to 20ms. In that case, if
you don't want to end up with an alarming number of dropped packets, the
DEFAULT_CCA_LENGTH should preferably set up to 20ms for instance. That way,
you ensure that a receiving node will poll the channel for long enough to
detect a preamble's transmission from the sender during the preambling
phase.

Regards
Vincent
_______________________________________________
Tinyos-help mailing list
[email protected]
https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help

Reply via email to