Study On Media Access Control Of VHF Frequency Hopping Radio

The facilities of wireless communication of battlefield are the key to guarantee theinformation to be unimpeded between commanders and combatants，as a flexible andreliable battlefield communication method，the study of new ultrashort wave radio andthe design of the protocol of the network becomes a hot spot of this field，and as weknow，the protocol of the Media Access Control layer is the hardest part of thisfield.Based on the situation above，the study and simulation technology of and design ofthe data link layer of ultrashort wave radio network was carried out by this paper，andalso there are theoretical and practical significance about the study.Based on in-depth analysis of the communication system and network protocol ofour country’s hopping radio and considering the requirement of the project，the topologyof ultrashort wave radio network was studied and an balanced hierarchical star networktopology was proposed；the main elements of ultrashort wave radio network simulationwas studied and the overall scheme and function design of ultrashort wave networksimulation were given.Within the TDMA protocol, considering the network topology、scale requirementand data transmission rate，the time slot allocation scheme and frame depth weredesigned， and a frame format of efficient transmission of short message wasimplemented，the flow features between the upper layer and lower layer of main nodeswas analyzed，so the methods of flow control was given，and rational error controlmethod was designed，and the TDMA protocol was implemented under the MATLABenvironment。Within the CSMA/CA protocol，the formats of control frame and data frame of theprotocol were designed，and two collision back-off algorithms were designed andimplemented，including binary exponential and stationary collision back-off，and it alsofinished the design of error control function，such as error retransmission and CRCchecksum.Finally the CSMA/CA protocol was also implemented under the MATLABenvironment.At last，protocol performance and network performance simulation of these twoprotocols were given,the realationship of these performance was analysed and it validate -d the feasibility of the protocols designed in this paper and gives a usabale referencefor the application of VHF radio network.