Amulti-channel MAC protocol forAUV networks

Thispaper presents results froma study on using multiple communication channels simultaneously foreffective networking ina small AUV network. AUVscan behighly mobile, leading totime-varying inter-node distances anda dynamic networktopology. We trytoexploit thismobility byusing multiple acoustic modemsoperating atdifferent frequency bands andsuited fordifferent ranges.We utilize a MAC protocol based on MACA thatuses RTS /CTS /DATA /ACK handshaking along withcarrier sensing. Datapacket trains areusedtogreatly enhance theperformance ofthisprotocol andresults showthat thisfeature makesita very viable protocol forunderwater networks ingeneral. Theprotocol exchanges AUV position information andusesthisinformation toallocate traffic tothe different modems.Thestudyisoriented towardstheuse of multiple AUVs inhighly co-operative missions whereeffective peertopeerdataexchange isvital. Theterm"channel" isusedto represent verydifferent capability modems,andisdifferent from thestandard context ofmulti-channel communications wherea single transceiver hastheoption tochoosebetweenmultiple channels, asinFDMA orCDMA. Inour model, we havemultiple andvery different transceivers beingusedsimultaneously. We name theprotocol MACA-MCP sinceitutilizes Multiple Channels andPositioning information. IndexTerms-adaptive clustering, multi-channel, medium access control, position information, underwatervehicle networks