Computer Engineering and Intelligent Systems www.iiste.org ISSN 2222-1719 (Paper) ISSN 2222-2863 (Online) Vol 2, No.4, 2011 1 A Review on Enhanced GPSR protocol For Wireless Sensor Networks P.Pranitha Department of CSE, JITS, Karimnagar, JNTUH, Hyd, AP, INDIA, Email: pranithareddy32@gmail.com G.Swamy Department of CSE, JITS, Karimnagar, JNTUH, Hyd, AP, INDIA, Email: swamy_gachi@yahoo.co.in Aakunuri Manjula Department of CSE, JITS, Karimnagar, JNTUH, Hyd, AP, INDIA, Email: manjula3030@gmail.com Abstract Greedy Perimeter Stateless Routing (GPSR), a novel routing protocol for wireless datagram networks that uses the positions of routers and a packet’s destination to make packet forwarding decisions. It also offers routing support for Wireless Sensor Network (WSN). However, GPSR was designed for the symmetric links (bidirectional reachable), but sensor networks are often asymmetric in nature. So, when the destination is outside the boundary GPSR suffers by energy inefficiency as it has to trace through all the nodes in the boundary for reaching the destination. In this paper a modified version of GPSR is proposed which identifies optimal route based on energy utilization and overcome problems in GPSR so that the feasibility of using GPSR in asymmetric WSN can be increased. The simulation results prove that the energy and delay is minimized and hence the proposed protocol outperforms the existing routing protocol for WSN. Keywords: Wireless sensor networks, GPSR, Ad hoc, Routing protocol 1. Introduction A Wireless Sensor Network (WSN) is a network consisting of individual nodes that are spatially distributed devices using sensors to cooperatively monitor physical or environmental conditions at different locations as shown in Fig.1. These nodes have to collaborate in order to fulfill their tasks and wireless communication is used to enable his collaboration [1]. Fig. 1 Architecture of Sensor networks