Node Feedback TCP Based Mechanism for Mobile Ad-hoc Network

Abstract

A mobile ad-hoc network is an autonomous system of mobile nodes establishing a network in the absence of any fixed infrastructure. Mobile ad-hoc network due to potentially high mobility have provided new challenges by introducing special consideration differentiating from the unique characteristics of the wireless medium and the dynamic nature of the network topology. Due to unique network formation, routing in mobile ad-hoc network is a challenging issue. Effort has been undergoing to transform TCP so that it could support routing function in an ad-hoc network. This research has discovered that most of the TCP based variant routing solutions of mobile ad-hoc network has not been successful in addressing problem at full. Taking TCP based routing solution as a main problem, this research has proposed a novel routing solution called Node feedback TCP based mechanism as a routing scheme for mobile ad-hoc network.Node feedback TCP based mechanism introduces a new flavor of TCP for mobile ad-hoc network. It follows an intermediate approach in between some of the existing mechanisms of TCP based schemes for mobile ad-hoc network. We have addressed TCP slow start mechanism in the context of mobile ad-hoc network and introduce measures through whom TCP can differentiate between real congestion and congestion assumed by TCP due to packet lost or route failure in mobile ad-hoc network. In addition our proposed mechanisms also deal with out-of-order delivery problem of TCP in mobile ad-hoc network. It is important to mention that NFBTCP not only address TCP related issues but also provides a number of different operations to assists in the smooth running of an ad-hoc network.The scheme has been developed in Java and Evaluated in SWANS. In the light of the simulation experiments, it could be seen that NFBTCP performed well in all simulation environment. It can be confirmed that NFBTCP has proven itself as a fully functional and operationalable for mobile ad-hoc network, thus should be seen or taken as a new novel TCP based solution for mobile ad-hoc network. A higher number of route requests and route replies representing networking activities were observed with the increase of mobile nodes. In addition to the messages activities, good numbers of routes were added at the end of each simulation cycle. It is quite understandable that the more routes available for data transfer in mobile ad-hoc network, the better. Moreover, such additions to the available routes could directly impact overall throughout. Lastly, nodes in mobile ad-hoc network suffer with limited resources. That makes conservation of all such resources an important issue in the context of mobile ad-hoc network. The results of simulation experiments validate the main concepts of the scheme especially congestion avoidance and out-of-order packet delivery. The scheme generates a higher number of routes suggesting that the implemented congestion avoidance and out-of-order packet delivery mechanisms of NFBTCP are successful in reducing the impact of link breakage since subsequently it was not possible for more routes to be added. The addition of more routes demonstrates that more packets are broadcast and suggests smooth flow of data and control packets. We believe NFBTCP offers a complete and an effective TCP based routing solution for mobile ad-hoc network.