Design of an energy-efficient geographic routing protocol for mobile ad-hoc networks

Mobile Ad-hoc networks extend communications beyond the limit of infrastructure based networks. Future wireless applications will take advantage of rapidly deployable, self-configuring multi-hop mobile Ad-hoc networks. In order to provide robust performance in mobile Ad-hoc networks and hence cope with dynamic path loss conditions, it is apparent that research and development of energy efficient geographic routing protocols is of great importance. Therefore various mobile Ad-hoc routing protocols have been studied for their different approaches. Forwarding strategies for geographic routing protocols are discussed and there is a particular focus on the pass loss model used by those routing protocols, the restriction and disadvantage of using such path loss model is then discussed. A novel geographic routing protocol which incorporates both the link quality and relay node location information has been developed to determine an energy efficient route from source to destination. The concepts of a gain region and a relay region to minimize the energy consumption have been proposed to define the area in where the candidate relay nodes will be selected with the minimized hop count. The signalling overhead required by the protocol has been analyzed in various scenarios with different traffic load, node densities and network sizes. Discrete event simulation models are therefore developed to capture the behaviour and characteristics of the operation of the developed routing protocol under different path loss conditions and network scenarios. A non-free space path loss model has been developed with a random loss between the nodes to simulate a realistic path loss scenario in the network. An enhanced signalling process has been designed in order to achieve advanced routing information exchange and assist routing determination. Comparison of simulated characteristics demonstrates the significant improvement of the new routing protocol because of its novel features, the gain region to ensure the deductiono f the energyc onsumptiont,h e relay region to ensuret he forward progress to the destination and hence maintain an optimised hop count. The simulation results showed that the energy consumption under the operation of the developed protocol is 30% of that with a conventionagl eographicarl outing protocol

MITIGATING NODE ISOLATION ATTACK IN OLSR PROTOCOL USING DCFM TECHNIQUE

A Mobile Ad Hoc Network (MANET) is a collection of mobile devices which are connected by wireless links without the use of any fixed infrastructures or centralized access points. The Optimized Link State Routing (OLSR) protocol is an important proactive routing protocol designed for mobile ad hoc networks. It employs periodic exchange of messages to maintain topology information of the network at each node. Based on topology information, each node is able to calculate the optimal route to a destination. One major DoS attack against the Optimized Link State Routing protocol (OLSR) known as the node isolation attack occurs when topological knowledge of the network is exploited by an attacker who is able to isolate the victim from the rest of the network and subsequently deny communication services to the victim. The proposed method named Denial Contradictions with Fictitious Node Mechanism (DCFM) relies on the internal knowledge acquired by each node during routine routing, and augmentation of virtual (fictitious) nodes. Moreover, DCFM utilizes the same techniques used by the attack in order to prevent it. DCFM successfully prevents the attack, specifically in the realistic scenario in which all nodes in the network are mobile

Security and Privacy Issues in Wireless Mesh Networks: A Survey

This book chapter identifies various security threats in wireless mesh network (WMN). Keeping in mind the critical requirement of security and user privacy in WMNs, this chapter provides a comprehensive overview of various possible attacks on different layers of the communication protocol stack for WMNs and their corresponding defense mechanisms. First, it identifies the security vulnerabilities in the physical, link, network, transport, application layers. Furthermore, various possible attacks on the key management protocols, user authentication and access control protocols, and user privacy preservation protocols are presented. After enumerating various possible attacks, the chapter provides a detailed discussion on various existing security mechanisms and protocols to defend against and wherever possible prevent the possible attacks. Comparative analyses are also presented on the security schemes with regards to the cryptographic schemes used, key management strategies deployed, use of any trusted third party, computation and communication overhead involved etc. The chapter then presents a brief discussion on various trust management approaches for WMNs since trust and reputation-based schemes are increasingly becoming popular for enforcing security in wireless networks. A number of open problems in security and privacy issues for WMNs are subsequently discussed before the chapter is finally concluded.Comment: 62 pages, 12 figures, 6 tables. This chapter is an extension of the author's previous submission in arXiv submission: arXiv:1102.1226. There are some text overlaps with the previous submissio

The New Multipoint Relays Selection in OLSR using Particle Swarm Optimization

The standard optimized link state routing (OLSR) introduces an interesting concept, the multipoint relays (MPRs), to mitigate message overhead during the flooding process. This paper propose a new algorithm for MPRs selection to enhance the performance of OLSR using particle swarm optimization sigmoid increasing inertia weight (PSOSIIW). The sigmoid increasing inertia weight has significance improve the particle swarm optimization (PSO) in terms of simplicity and quick convergence towards optimum solution. The new fitness function of PSOSIIW, packet delay of each node and degree of willingness are introduced to support MPRs selection in OLSR. The throughput, packet loss and end-to-end delay of the proposed method are examined using network simulator 2 (ns2).  Overall results indicate that OLSR-PSOSIIW has shown good performance compared to the standard OLSR and OLSR-PSO, particularly for the throughput and end-to-end delay. Generally the proposed OLSR-PSOSIIW shows advantage of using PSO for optimizing routing paths in the MPRs selection algorithm