I am wondering if disabling CCA check before sending a packet also
implies that i will not be able to detect collision.
If am not interested in detecting collision i would see CCA to false.
But checking CC2420 radio stack and precisely in attemptSend()
it seems that the stack just send the packet, using either STXONCCA or
STXON, but still manages congestions even if
m_cca was set to false. I past a piece of code from the
CC2420TransmitP.nc module
> status = m_cca ? call STXONCCA.strobe() : call STXON.strobe();
> if ( !( status & CC2420_STATUS_TX_ACTIVE ) ) {
> status = call SNOP.strobe();
> if ( status & CC2420_STATUS_TX_ACTIVE ) {
> congestion = FALSE;
> }
> }
>
> m_state = congestion ? S_SAMPLE_CCA : S_SFD;
> call CSN.set();
> }
>
> if ( congestion ) {
> totalCcaChecks = 0;
> releaseSpiResource();
> congestionBackoff();
> } else {
> call BackoffTimer.start(CC2420_ABORT_PERIOD);
> }
>
Shouldn't the last if (congestion) be executed if and only if CCA was
set to true and congestion detected? The default value of congestion is
TRUE.
Thanks
Alessandro
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