Cross-LayeredMAC and Routing Algorithm for
Seung-seok Hong, Seung-Jun Lee · 2008
When thereal-time traffic istransmitted under multi-hop networkbasedon IEEE 802.11, therearemany problems like thedegradation ofthroughput, delayandhigher framedropbybottle-neck. We canclassify thesolution about these problems into three cases, i.e. modification ofmediaaccess control (MAC)algorithm, definition andusageofrequired new packet, anduseofmulti-channel. Oneofmodification ofMAC algorithm, i.e., themethodwhichbothRTS andACK are transmitted simultaneously isquite useful toreduce thedelay in thereal-time traffic. Alsorouting algorithm hastotreat packets differently according totraffic types. Theinteraction between routing algorithm innetwork layer andMAC layer isrequired to differentiate QoSfordifferent traffic type, whichresults inthe cross-layer mechanism. Inthispaper,proposed cross-layer algorithm, namedasDifferentiated Data-driven Cut-through MediumAccess(DDCMA),integrates themodified MAC algorithm and modifiedad-hocroutingalgorithm with cross-layer interaction toprovide theefficiently differentiated QoSbetweenreal-time andnon-real-time traffics. DDCMA is basedonexisting DCMA inMAC layer andenhanced DSRfor networkrouting andtargets fordifferentiated QoS between real/non-real-time traffics. Theperformance validation hasdone extensively usingGloMoSim, well-known multihop network simulator.