DBET: Demand Based Energy efficient Topology for MANETs

Abstract

Energy efficient topology in Ad-hoc networks can be achieved mainly in two different ways. In the first method, network maintains a small number of nodes to form a connected backbone and the remaining nodes sleep to conserve energy. This method is effective for low traffic networks. Energy efficiency in the second method is achieved by power control technique. This technique is effective in high traffic conditions. The first method is not effective in high traffic conditions. Similarly, the second method is not effective in low traffic networks. So, in this paper we propose a Demand Based Energy efficient Topology (DBET) to reduce the energy consumption for mobile ad hoc network, by dynamically adjusting the topology for various network traffic conditions. We have simulated our proposed protocol DBET by using AODV (8) as routing protocol in network simulator ns2.33 (1) and compared with AODV and SPAN (3). The simulation studies revealed that the proposed scheme perform better in terms of energy, delay, and delivery ratio.in this paper newly we are implementing the security factor while sending the packets. For that we using RSA algorithm. I. Introduction Mobile Ad-hoc Networks (MANETs) are self-organizing, self-configuring and infrastructure-less multi-hop wireless net-works, where each node communicates with other nodes directly or indirectly through intermediate nodes without any infrastructure. Such temporary networks can be used in battle-fields, disaster areas, military applications, mining operations and robot data acquisition. Besides these characteristics they present challenges like limited energy, dynamic topology, low bandwidth and security. The description of the arrangement of the MANETs, called topology, is usually temporary or dynamically changed with time. Energy conserving is one of the challenges because of limited battery resource. The techniques which are used to reduce the initial topology of network to save the energy and increase the lifetime of network, with the preservence of network connectivity, called topology control techniques. Various techniques, in network layer, are proposed in the literature to conserve energy. These techniques can be clas-sified mainly into two categories: by controlling the number of nodes with the smaller link cost. In the first method a small number of nodes awake to maintain the network connectivity and remaining nodes go into sleep state to conserve energy. This method is effective in low traffic conditions, because the power consumption to keep nodes awake dominates the power consumption in data transfer. In the second method, topology is controlled by keeping lesser cost links in the network. This method is effective in high data traffic because power consumption in data transfer dominates the power required to keep nodes awake. We combine the advantages of these two techniques to dynamically adjust network topology for various network traffic conditions. In this paper, we present a demand based energy efficient topology (DBET) that dynamically adjust network topology for various network traffic conditions. We have simulated our proposed protocol DBET by using AODV (8) as routing protocol using network simulator ns2.33 (1) and compared with AODV and AODV with SPAN (3). The simulation studies revealed that the proposed scheme perform better in terms of energy, delay, and delivery ratio. In general network topology is controlled by keeping small number of nodes awake as in the first technique. The proposed DBET keeps more number of nodes along the bulk data transfer path to conserve energy by keeping low link cost as in the second technique. The rest of the paper is organized as follows: the next section provides a brief review of related studies. The third section gives the design details of proposed DBET. Integration issues of DBET with routing protocol is discussed in the forth section. Simulation results along with discussions are provided in the section 5. The last and final section concludes the paper with same pointers to future research direction. II. Related Work We briefly describe various techniques related to our work topology control. Different topologies have been proposed in the literature to reduce the energy consumption. These methods can be classified into centralized controlling and distributed computing methods. Ideally, for mobile ad hoc network a topology should be computed and maintained in distributed, asynchronous, and localized manner. Li and Wan (6) described a distributed protocol to construct a minimum power topology and developed an algorithm which directly find a path whose length is within a constant factor of the shortest path. The length of the path is measured in term of energy consumption. This proposed algorithm used only local information.