Showing papers by "Mehran Abolhasan published in 2005"

Performance Investigation on three-classes of MANET Routing Protocols

Abstract: Routing in ad hoc networks has received significant attention with a number of different routing protocols proposed in recent years. These routing protocols may be classified into three main categories: proactive, reactive and hybrid. Prior work aimed at comparing the performance of routing protocols has mainly focused on comparing reactive and proactive protocols. In this paper, we present a simulation study of different routing protocols from all three categories. We also explore the benefits and performance of each routing category. Further, we present a discussion of future research directions for routing in ad hoc networks.

Efficient and Highly Scalable Route Discovey for On-demand Routing Protocols in Ad hoc Networks

Abstract: This paper presents a number of different route discovery strategies for on-demand routing protocols, which provide more control to each intermediate node make during the route discovery phase to make intelligent forwarding decisions. This is achieved through the idea of self-selection. In self-selecting route discovery each node independently makes route request (RREQ) forwarding decisions based upon a selection criterion or by satisfying certain conditions. The nodes which do not satisfy the selection criterion do not rebroadcast the routing packets. We implemented our self-selecting route discovery strategies over AODV using the GloMoSim network simulation package, and compared the performance with existing route discovery strategies used in AODV. Our simulation results show that a significant drop in the number of control packets can be achieved by giving each intermediate node more authority for self-selection during route discovery. Furthermore, a significant increase in throughput is achieved as the number nodes in the network is increased

A new strategy to improve proactive route updates in mobile ad hoc networks

Abstract: This paper presents two new route update strategies for performing proactive route discovery in mobile ad hoc networks (MANETs). The first strategy is referred to as minimum displacement update routing (MDUR). In this strategy, the rate at which route updates are sent into the network is controlled by how often a node changes its location by a required distance. The second strategy is called minimum topology change update (MTCU). In this strategy, the route updating rate is proportional to the level of topology change each node experiences. We implemented MDUR and MTCU on top of the fisheye state routing (FSR) protocol and investigated their performance by simulation. The simulations were performed in a number of different scenarios, with varied network mobility, density, traffic, and boundry. Our result indicate that both MDUR and MTCU produce significantly lower levels of control overhead than FSR and achieve higher levels of throughput as the dencity and the level of traffic in the network are increased.

An optimised resource aware approach to information collection in ad hoc networks

Abstract: In ad hoc networks there is a need for all-to-one protocols that allow for information collection or ''sensing'' of the state of an ad hoc network and the nodes that comprise it. Such protocols may be used for service discovery, auto-configuration, network management, topology discovery or reliable flooding. There is a parallel between this type of sensing in ad hoc networks and that of sensor networks. However, ad hoc networks and sensor networks differ in their application, construction, characteristics and constraints. The main priority of sensor networks is for the flow of data from sensors back to a sink, but in an ad hoc network this may be of secondary importance. Hence, protocols suitable to sensor networks are not necessarily suitable to ad hoc networks and vice versa. We propose, Resource Aware Information Collection (RAIC), a distributed two phased resource aware approach to information collection in ad hoc networks. RAIC utilises a resource aware optimised flooding mechanism to both disseminate requests and initialise a backbone of resource suitable nodes responsible for relaying replies back to the node collecting information. RAIC in the process of collecting information from all nodes in an ad hoc network is shown to consume less energy and introduce less overhead compared with Directed Diffusion and a brute force approach. Importantly, over multiple successive queries (in an energy constrained environment), the use of resource awareness allows for the load of relaying to be distributed to those nodes most suitable, thereby extending the lifetime of the network.

Highly scalable routing strategies: DZTR routing protocol

Abstract: In this paper we present a simulation study of a hybrid routing protocol we proposed in our previous work [4] [3]. 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.