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In wireless ad hoc networks, the traditional routing protocols make the route selection based on minimum distance between the nodes and the minimum number of hop counts. Most of the routing decisions do not consider the condition of the network such as link quality and residual energy of the nodes. Also, when a link failure occurs, a route discovery mechanism is initiated which incurs high routing overhead. If the broadcast nature and the spatial diversity of the wireless communication are utilized efficiently it becomes possible to achieve improvement in the performance of the wireless networks. In contrast to the traditional routing scheme which makes use of a predetermined route for packet transmission, such an opportunistic routing scheme defines a predefined forwarding candidate list formed by using single network metrics. In this paper, a protocol is proposed which uses multiple metrics such as residual energy and link quality for route selection and also includes a monitoring mechanism which initiates a route discovery for a poor link, thereby reducing the overhead involved and improving the throughput of the network while maintaining network connectivity. Power control is also implemented not only to save energy but also to improve the network performance. Using simulations, we show the performance improvement attained in the network in terms of packet delivery ratio, routing overhead, and residual energy of the network.

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No abstract

In wireless ad hoc networks, traditional routing considers hop count and distance for making the route selection. The network is prone to various types of attacks by intruders in which packets maybe modified or dropped. A trust based mechanism maybe employed in which the nodes are constantly monitored for malicious behaviour. An abnormality in the behaviour of the intermediate node effects the trust value and such malicious nodes that are detected maybe excluded from the route and a new route discovery maybe initiated. In this paper, such a trust based routing is proposed to detect network layer attacks. A route discovery is initiated under the detection of malicious nodes as against the use of control packets for route rediscovery. Using simulation, it is proved that the proposed scheme achieves better performance in terms of Packet Delivery Fraction, end-to-end delay and therefore improves the performance of the network under adverse environment