Effect of Ad Hoc Routing Protocols on TCP Performance within MANETs

TCP was mainly developed to be deployed within wired networks. Recently, many researches have studied its performance within mobile ad hoc networks (MANETs). These researches found that TCP performance are highly influenced by the characteristics of such networks. This is due to TCP´s reliability mechanism and its inability to discriminate the packet loss cause. Indeed, unlike wired networks, where packet loss is mainly caused by network congestion, in MANETs we could have many other reasons to lose a data packet. However, TCP considers that all packet losses are due to network congestion. This enforces TCP to be aggressive in front of certain types of loss. Packet losses in MANETs can be either related to wireless communication environment (i.e. the effect of fading, interference, multipath routing, etc.) or to the dynamic nature of such networks (i.e. link failures, network partitioning). This latter could be due to the node mobility or to the node battery depletion. This could lead to frequent route re-computation within the network. In this work, we intend to study the effect of ad hoc routing protocols on TCP performance (energy consumption and average goodput) within MANETs. We consider studying different types of ad hoc routing protocols having different characteristics: reactive vs. proactive, distance vector vs. link state, and source routing. Our study results show that; DSDV as a proactive distance vector routing protocol leads to most accepted TCP performance results and this is confirmed at different mobility levels