The Performances Of C-ARQ Protocol With Frame Combiner In Ad Hoc Networks

Ad Hoc network,as a kind of multiple hops,no center,self-organized wireless network,each node has extremely strong autonomy,so the first thing we studied is the internal control mechanism of each node.Using the Geom/G/1 queue system and Little theorem to calculate the average queue length,node information node average length of queue.In the actual process of communication,node within the cache is limited,so the queue length of nodes is unlikely to be infinite.We further use the Geom/G/1/7)queue system to analyze system,getting indicators channel utilization rate,packet loss rate,which can reflect the system performance.The congestion control problem is studied by investigating the RED algorithm of active queue management,and the improvement of RED algorithm is proposed as Sec-RED and Sin-RED.We consider a cooperative automatic repeat request(C-ARQ)with a frame combiner.The performance of the system is analyzed under the assumption that destination node can receive the frame from cooperators certainly.In this paper,we present a Markov model and use it in C-ARQ protocol with or without frame combiners to solve the throughput of system.After solving throughput from Markov chain and computing the overhead of system,we found that frame combiners not only lead to a high throughput,but a high overhead,too,so we consider to find an optimum balance between high throughput and low overhead by means of multi-objective optimization algorithm.