Method for contention-free NPD periodic updating

摘要

Methods and apparatus for a next-in-line protecting device to periodicallybroadcasting its existence in a communication system. A next-in-line protectingdevice periodically transmits the next-in-line codeword to inform a primaryprotecting device and a plurality of secondary devices that the next-in-linedevice still exists in a communication system. The NPD transmits the NPD codewordintelligently in order to reduce the probability of collision with the RTS codewordstransmitted by the other SPDs.