Hi. Can anyone help me with a question about low power listening protocol?
As I understand based on TEP 126 and B-MAC paper, when a node wishes to transmit a packet, it transmit the full packet over and over again for twice the check interval of the intended receiver.
My question is: Are these repeated transmissions of a same packet comes back to back? or can be interrupted by other simultaneous transmitters due to failed channel contention?
If the second case is true, then it could be possible that a packet will never be delivered due to either (1). the transmitter gets chance to transmit, but the receiver is sleeping, or (2). the receiver wakes up, but it's not the transmitter's turn to transmit. This makes me feel like transmitting twice as long can only increase probability of transmission success, but doesn't guarantee it. Also, I checked the file "DefaultLplP", it looks like "sendDoneTimer" is responsible for limiting the # of transmissions, but "
call SendDoneTimer.startOneShot(
call LowPowerListening.getRxSleepInterval(currentSendMsg) + 20);" means the "sendDoneTimer lives only for rxsleepinterval+20 time?
Thank you very much
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