Research On Key Technology Of Mac Protocol For Large-Scale MANET

With the rapid development of wireless communication technology,Mobile Ad Hoc Network(MANET)has been more and more applied.However,the scale cannot meet the current application requirements.Therefore,the research on large-scale MANET is very urgent.As one of the key technologies of MANET,Medium Access Control(MAC)protocol control nodes access the channel without conflict,which has a decisive impact on the performance of the entire network.This paper mainly studies the large-scale MAC protocol.In the design process of Clustered-Dynamic TDMA Slot Assignment Protocol(C-DTSAP)based on clustering structure in large-scale MANET,there are three key points should be faced.That is how to efficiently resolve conflicts with slot application,how to efficiently reduce channel access delay in large-scale MANET,and how to improve the utilization of slot better.This paper studies and analyzes the above three key points,and innovatively proposes corresponding solutions in combination with the slot allocation algorithm.That is slot conflict resolution strategy,slot selection strategy,maximum distance sequence algorithm and slot release strategy.First of all,this paper introduces the classification of existing MAC protocols,including analyzing the design ideas of the classic MAC protocol and the problems in its application in large-scale MANET.At the same time,it analyzed the performance of large-scale MAC protocols should be.Next,the design of C-DTSAP is described.Then it focus on the application of slots in the intra-cluster and inter-cluster in the slot allocation process and proposes a complete set of slot conflict resolution strategy.After that,based on the queuing theory,the influence of the different position of slot allocated on the channel access delay of the C-DTSAP is analyzed.The analysis shows that the position of assigned slot is a uniform state,which have little effect on the channel access delay.Therefore,the maximum distance sequence algorithm is proposed and the slot selection strategy based on the maximum distance sequence is proposed.Moreover,considering different slot occupancy situations,the slot release strategy with active release and passive release is proposed to improve slot utilization.Finally,C-DTSAP is modeled through OPNET.Different simulation scenarios are established to simulate and analyze the performance of C-DTSAP.Then compare the performance of the clustered C-DTSAP and un-clustered FC-USAP(Fast Convergence-Unifying Slot Assignment Protocol)in different scale networks.The simulation results show that the clustered C-DTSAP shows good performance in channel access delay and slot utilization,and the overall performance is significantly better than FC-USAP in large-scale networks.