Prepare tone: Enhancing broadcast-packet transmission of multiple rendezvous Mac performance in multiple-channel ad hoc network

Multiple Rendezvous approaches utilized multi-channel which was only with a single transceiver radio may enhance Mac throughputs of multi-channel ad hoc network no less than that of other approaches which need extra radios or hardware for time synchronization. However, for the media-access methods of Multiple Rendezvous, nodes in ad hoc network should be listening on different channels to preserve the control packets of any data transmission with noneinterference each other. Therefore, for any broadcast data packet or multicast data packet, it should be transmitted to its destinations like a set of single-cast data packets. And then other performances of ad hoc network as routing may be reduced by the high overload of broadcast packet. In order to reduce the transmission number of a broadcast packet, a method of using prepare tones (single-cast tone and broadcast tone) before data-packet transmission is presented, we called it PTMC (Prepare Tone for Media-access Control). In the method of PTMC, any broadcast packet will be send out only once to preserve it can reach any idle destination, which is not sending or receiving any data-packets at that time, nevertheless any single-cast packet will be matched and send out just as MAXM done. Simulation results among PTMC, MAXM and SSCH show: If every broadcast packet was send to potential receivers one by one, the throughputs of ad hoc network routed by AODV and media controlled by MAXM or SSCH may not be improved as the available channel number is increasing, for reasons of the routing discovery time increasing. Using PTMC to solve this problem, whatever data-traffics or available channels are provided, the throughput of PTMC will be better than the other two. Thus with available channels increasing, the throughput of PTMA is improved.