Abstract: Wireless sensor networks(WSNs) is a network that is formed when a set of small sensor devices those are deployed in an adhoc fashion cooperates for sensing a physical phenomenon.In this paper, we evaluate some of the widely used efficient routing protocols with varying transmission range of the node. Data transmitted by a node is received by all the nodes within its communication range. Our main focus is on the analysis of varying a range of the transmission in rhe terms of distance. The evaluation is made on the three routing protocols such as : directed diffusion, flooding and omniscient multicast, which are simulated in Network Simulator (NS-2) .The performance of these data dissemination protocols, is analyzed with selected metrics.

Keywords: Wireless sensor networks(WSNs); Quality of service(QOS); Directed diffusion (DD);NS-2(network simulator-2).