Analysis of Selective Routing Strategies for Fault Tolerance In Wireless Sensor Networks Fleena Christy M.E Pervasive Computing Technologies, Anna University of Technology, Tiruchirappalli-620 024, Tamil Nadu-India, fleena.christy@gmail.com. V R Sarma Dhulipala Assistant Professor (Physics), Centre for Convergence of Technologies, Anna University of Technology, Tiruchirappalli-620 024, Tamil Nadu-India, dvrsarma@gmail.com. Abstract: Wireless sensor networks are intended to have large number of sensor nodes which are widely deployed in a distributed environment. Steep increase in number of nodes, which is a deviant to WSN eventually, affects the communication capability of the network as it raises the scalability issue. This at any instance may destabilize network throughput which leads to network failure. Therefore, fault- tolerant protocol is desperately needed to stabilize the dexterity of network. In this paper, we have examined the two prominent routing protocols DSDV and AODV which has been the inception for evolution of numerous routing protocols for wireless network environments. We have summarized the execution evaluation of the significant parameters (i.e.) throughput, packet delivery ratio and end-to-end delay by varying the transmission range for different node densities to analyze which mechanism well suits for the trustworthy WSN environment. Keywords: WSN, AODV, DSDV, node density, transmission range. I. INTRODUCTION: WSNs are envisioned to have wide variety of applications as it is fundamentally a new tool in wireless research community which provides limitless future potentials. It has emerged as a premier research topic since it is a significant resent perception in the area of wireless technology. They have the great enduring economic potential to transform our lives as it is significantly different with classical networks because of limitations on the simplicity of the processing power of nodes, energy consumption and possibly highly dynamic environmental [1]. It also poses several new conceptual and optimization problems since it consist of numerous diminutive sensor nodes which are deployed at high density in regions requiring surveillance and monitoring [2]. Due to limited energy provision, the energy resource of sensor networks should be wisely managed to extend the lifetime of sensors [3]. Routing mechanisms are the core part of wireless sensor networks [4].So when WSN environment changes, as its implication, performance of routing protocol tends to cause temporary or permanent failure of the network. This failure usually are due to the fast energy depletion of the sink node i.e., energy hole, caused when the transmitting nodes are not in the range between one another in WSN [3]. In such case, they need to rely on multi-hop communications and in such constraint, routing becomes mandatory. To overcome such criteria, support of transmission range is needed because impact of the radio transmission range affects the network throughput as the number of nodes exceeds. A higher transmission range increases the distance progress of data packets towards their final destination with increased throughput [5]. Since, network routing protocols must be designed to achieve fault tolerance in the presence of individual node failure. Therefore fault-tolerant mechanism finds the significance for a successful communication in WSN. Realizing fault-tolerant operation is critical issue for a successful WSN environment. It is the ability of the system to sustain functionalities without any disturbances or interruptions [6]. Fleena Christy et al. / International Journal on Computer Science and Engineering (IJCSE) ISSN : 0975-3397 Vol. 4 No. 05 May 2012 749