Degree Name

Doctor of Philosophy


School of Electrical, Computer and Telecommunications Engineering


The 1990s have seen a rapid growth in research interests in Mobile Ad hoc Networking. The infrastructureless and the dynamic nature of these networks demand new set of networking strategies to be implemented in order to provide efficient end-to-end communication. This, along with the diverse application of these networks in many different scenarios such as battlefield and disaster recovery, have seen MANETs being researched by many different organisations and institutes. M A N E T s employ the traditional TCP/IP structure to provide end-to-end communication between nodes. However, due to their mobility and the limited resource in wireless networks, each layer in the TCP/IP model requires redefinition or modifications to function efficiently in a MANET . One interesting research area in M A N E T is routing. Routing in the MANET s is a challenging task and has received a tremendous amount of attention from researches. This has led to development of many different routing protocols for MANETs , and each author for each protocol proposed argues that their strategy provides an improvement over a number of different strategies in the literature for a given network scenario. Therefore, it is quite difficult to determine which protocols may perform best under a number of different network scenarios, such as large node density and traffic.

In this thesis we investigate the scalability of the current routing protocols designed for MANETs and propose a number of different routing strategies to provide higher levels of scalability. The proposed strategies use the services provided by a Global Positioning System (GPS) to achieve their objectives.

Our study begins by describing the research question for this thesis and provide a theoretical performance comparison between a number of different types of solutions presented to solve this problem.

Next, we propose a proactive routing strategy called Minimum Displacement Update Routing (MDUR) along with a number of different variations and improvements to this strategy. MDUR , uses notion of minimum topology change to reduce the number of routing overhead packets and hence provide higher scalability.

We then introduce three different routing strategies which are based on point-to-point on-demand routing, such as in Ad hoc On-demand Distance Vector (AODV). Location-based Point-to-point Adaptive Routing (LPAR), presents different location tracking strategies which reduce the number of re-broadcasting nodes during the route discovery phase when the source node has location information or previous knowledge about the destination. It also presents a number of different strategies to reduce the effect of route failure during data transmission. LPAR-S, extends LPAR by performing routing over stable links only. Position-based Selective Flooding (PSF), presents a new approach to discovering routes when the source node has no previous knowledge about the destination. This strategy reduces the number of retransmitions to a set of nodes which lie within the forwarding region of the previously retransmitting node. W e present a simulation study for each routing strategy and propose a number of variations and improvements for them.

Finally, we propose a new hybrid routing protocols for MANETs. We refer to this protocol as Dynamic Zone Topology Routing (DZTR). DZTR uses a combination of our dynamic zone creation algorithms and a number of different location tracking strategies to provide high levels of scalability in large MANETs consisting of large volumes of traffic. W e investigated the performance of DZTR by theoretical analysis and simulations. Our results indicate that DZTR scales higher than a number of different types of routing protocols proposed in the literature.



Unless otherwise indicated, the views expressed in this thesis are those of the author and do not necessarily represent the views of the University of Wollongong.