Static and Dynamic RED Tuning for TCP Performance on the Mobile Ad Hoc Networks

In the past several years, many researchers and experts have focused on the studies of routing protocols over Mobile Ad Hoc Networks (MANETs). Today, the pervasion of Internet applications causes TCP as the standard data transfer protocol for most of networking applications. For achieving reliable data delivery, TCP provides mechanisms of flow and congestion control, where RED is one of the most commonly adopted flavors. Due to the unconstrained movement of the mobile nodes, TCP is unable to distinguish network congestion from link down in MANETs. The average queue length of RED will be longer than MinThreshold if the link re-establishment takes too much time. Then, it will invoke the sender to perform relative congestion control. Therefore, it may degrade the TCP performance before the link reestablishes completely. Hence, the main purpose of this paper is to adjust related parameters of RED for evaluating the performance and propose the tuning strategies in RED to improve the TCP performance in MANETs. Also, we design a simulator with ns-2 to perform simulations. Consequently, the final results indicate that we can obtain better TCP performance through static and dynamic tuning approaches in MANETs. The proposed novel tuning methods of this paper can be the reference for further studies in QoS features and other applications on the Ad-Hoc Wireless Networks.