A Survey on Geographic Routing Relay Selection in Wireless Sensor Network Santosh Kumar K 1 , Dr.N.Duraipandian 2 1. PG Scholar, Department of Computer Science and Engineering, Velammal Engineering College, Chennai, Tamilnadu, India. 2. Professor, Department of Computer Science and Engineering, Velammal Engineering College, Chennai, Tamilnadu, India. Email: santhosh2567@gmail.com 1 , emailpandiandurai@gmail.com 2 ABSTRACT: Geographic routing (or position-based routing) is the technique which employs position information of nodes while routing from the source to the sink. Geographic routing has been considered as a simple, effective and scalable routing protocol for designing a variety of applications ranging from mobility prediction, management of nodes and metrics such as hop count, power, relay selection, energy consuming, delay, etc. Most geographic routing algorithms use a greedy strategy for selecting the neighbor closest to the sink as a next hop. However, greedy forwarding fails in reaching a node that is closer to the sink than all its neighbors and so planar graph routing is adopted which guides the packet with guarantees delivery. Geographic routing algorithms exploit location information but the problem exist is convergecasting around connectivity holes and relay selection of each node. For resolving these issues, an alternative method termed ALBA_R was proposed along with enhanced relay selection mechanism in order to maximum the lifetime of a node. I. INTRODUCTION A Wireless Sensor Networks (WSN) has been emerged as a promising area for research and scientific advancement. WSNs are greatly applied in many application domains such as surveillance, environmental monitoring, vehicular applications, defense applications, traffic systems, medical monitoring, precision agriculture, etc. WSN consist of nodes with sensing (measuring), computing, and wireless communications capabilities. Technology upgradation in WSN is the result of integration of sensor, transceiver, memory and microcontroller technologies on single unit called sensor node. The Sensor Node, a basic element of WSN capable of observing(sensing) physical capabilities, process the monitored and received information and communicate the observed or processed information to the nearby sensor nodes to form a network of sensor nodes. Fig.1 components of a sensor node Many sensor nodes are randomly distributed over larger distance and each sensor node having data content were gathered in the sink. Through internet everyone can view the collected data in the network. As shown in Fig.1, it consists of three major components namely Sensing unit, processing unit, and Transmission unit. They include some additional components like position finding system, power supply and a mobilizer. Sensing unit composed of two subunits such as Sensors and Analog-to-Digital Converters (ADCs).The analog signals are measured by the sensors are digitized through an ADC and in turn fed into the processing unit (storage unit and a processor). The processor and its associated memory commonly RAM is used to manage the procedures that make the sensor node carry out its assigned sensing and collaboration tasks. In Transmission unit, the transceiver connects the node with the network and serves as the communication medium of the node. The power supply/battery is the most important component of the sensor node because it implicitly determines the lifetime of the entire network. Proceedings International Conference On Advances In Engineering And Technology ISBN NO: 978 - 1503304048 www.iaetsd.in International Association of Engineering & Technology for Skill Development 11