TCP, XCP and RCP in Wireless mesh networks: An evaluation study

TCP is the most widely used congestion protocol in the Internet. However, TCP has some limitations, even in the wired world, such as not providing high utilizations in high bandwidth-delay product networks, and introducing high load and overhead in the network. Due to these limitations, several congestion protocols have been proposed. Some of the most known and recent protocols developed to provide faster and lighter congestion control are eXplicit Control Protocol (XCP) and Rate Control Protocol (RCP). These protocols have been proposed essentially to work in wired networks and environments; however, there are already new versions of XCP for wireless networks. Since these protocols have a large acceptation on the research field, and simultaneously,Wireless mesh networks (WMN) are in undergoing rapid progress, it is important to evaluate how XCP and RCP behave in these networks, as compared to TCP. This paper presents an evaluation study of TCP, XCP and RCP in WMNs, studying different WMN scenarios. Surprisingly, the results show that TCP is more efficient in mesh scenarios, being more fair and stable than XCP and RCP. To obtain the available network capacity, both XCP and RCP need that all nodes in the network cooperate, which increases network overhead, and reduces performance and fairness. Moreover, their capacity evaluation is not accurate in wireless networks.