About CCA treshold and failure

Hello everybody,

I have 4 nodes (node A, node B, node C and node D). Node A Tx to node D all the time (without delays) at the max power (like -40dBm considering the distance between the nodes), node B check all the time the energy channel (thats the reason of the -40dBm mentioned before), node C Tx to node D at max power with a delay of 5 seconds and this the node which has a CCA Treshold about 46HEX=-70dBm, and finally node D just receives packets all the time. The thing is because node C is configured with a CCA treshold about -70dBm it ca’t Tx any packets when node A Tx all the time because node makes that the energy channel was -40dBm as I can see in node B, but this doesn’t happen. Althought the channel has -4dBm, node C Tx without problems considering that the CCA treshold is -70dBm.

Also I just want to know how to use the CCA counter in order to get how many times the Tx fail because the energy of the channel was above the CCA treshold. Is any code example using this ?.


My question is why CA is not working well at my waspmote. I’m srure that the channel has more energy than the treshold and anyway my nodes Tx without problems