David Valencia wrote: > Does the packet link layer use CCA when retransmitting a packet? > > > If CCA is on (it is by default), it is used for each transmission or retransmission (look through the components\tos\chips\cc2420\csma\CC2420CsmaP.nc and \tos\chips\cc2420\transmit\CC2420TransmitP.nc). Anton.