In this paper we present a simulation study of a hybrid routing protocol we proposed in our previous work. Our hybrid routing strategy is called Dynamic Zone Topology Routing protocol (DZTR). This protocol has been designed to provide scalable routing in a Mobile Ad hoc Networking (MANET) environment. DZTR breaks the network into a number of zones by using a GPS. The topology of each zone is maintained proactively and the route to the nodes in other zones are determined reactively. DZTR proposes a number of different strategies to reduce routing overhead in large networks and reduce the single point of failure during data forwarding. In this paper, we propose a number of improvements for DZTR and investigate its performance using simulations. We compare the performance of DZTR against AODV, LAR1 and LPAR. Our results show that DZTR has fewer routing overheads than the other simulated routing protocols and achieves higher levels of scalability as the size and the density of the network is increased
