Modeling active queue management based on transmission control protocol in Ad Hoc network
基于传输控制协议的无线自组网主动队列管理建模

The active queue management(AQM) is usually concerned with the queue controller design. As a controlled object, the transmission control protocol(TCP) is often realized by the simulation of Network Simulator(NS). Thus, it is necessary to study the characteristics of TCP and AQM in Ad Hoc network. Differential equations for the TCP windowsize and queue-length are developed based on the TCP window additive-increase multiplicative-decrease algorithm and the queuing principle. Next, the differential equation of the congestion-loss probability is derived based on the proportionalintegral AQM control. Then, the Ad Hoc network TCP/AQM differential model is proposed through the simultaneous differential equations. The comparison simulations show that the new model can estimate Ad Hoc network performance. The model research also shows that the number of hops, wireless loss and the very small queue become the bottleneck of the AQM performances. Furthermore, the queue information can help TCP discriminate between congestion loss and wireless loss in Ad Hoc network.