Patent ID: 7619980

Claim:
A system configured to transmit and receive messages via a wireless medium and/or a wire medium, minimizing transmission delays and avoiding loss of synchronization, using a contention based multiple access protocol, which system comprises n transceiver means, wherein n is an integer and n≧2, wherein each transceiver means comprises a detection means operable to detect the condition of said medium, wherein each transceiver means also comprises a control means connected to said detection means operable to switch said transceiver means from receiving to transmitting or vice versa, wherein each transceiver means also comprises a back-off counter connected to said control means operable to decrement its count at the end of each time slot in a sequence of time slots when performing a back-off procedure, wherein a transceiver means which wishes to transmit and is performing said back-off procedure for which said detection means detects that said medium is busy, said control means freezes said back-off counter and if this medium busy condition is subsequently determined to be a false alarm said control means resumes said back-off counter at the beginning of the immediate next time slot in the sequence of time slots after the time slot in which rejection of said false alarm occurs, using the time slot timings in force prior to said false alarm event.