Link and Location Based Routing Mechanism for Energy Efficiency in Wireless Sensor Networks

— In Wireless Sensor Networks, sensed data are reported to the sink by the available nodes in the communication range. The sensed data should be reported to the sink with the frequency expected by the sink. In order to have a communication between source and sink, Link based routing is used. Link based routing aims to achieve an energy efficient and reliable routing path. This mechanism considers the status (current energy level in terms of Joules) of each node, link condition (number of transmissions that the Cluster Head (CH) and the Gateway (GW) candidates conducts) and the transmit power (power required for transmission in terms of Joules). A metric called Predicted Transmission Count (PTX) for each node is calculated using its status, link condition and transmit power. The node which has highest PTX will have the highest priority and it will be the potential candidate to act as CH or GW. Thus the selection of proper CH or GW reduces the energy consumption, and the network lifetime is increased. I. INTRODUCTION The Wireless sensor network (WSN) is promising network architecture. It used in many applications such as monitoring the environment, detecting the object, tracking the event, and security surveillance [1]. WSNs consist of large numbers of very small autonomous wireless devices, called sensor nodes. Sensor nodes perform multiple functions such as sensing, computing, and communication [2]. In typical WSNs, a central node called sink, which sends query message to other nodes in the network. The sensor nodes (i.e., source nodes) must report the sensing or monitoring data to the sink. Charging batteries for sensor nodes is often difficult since the sensor nodes are battery-powered devices. Data transmission is the major source of energy consumption compared to sensing, communication, and computation [3]. Thus, it is important to design an energy efficient routing scheme for reporting the sensed data to achieve a high delivery ratio and to increase the lifetime of network. The three categories of routing protocols available in the existing systems of WSNs: chain-based, tree-based, and cluster-based [4]. In the chain-based routing protocol, the farthest node from the sink becomes the leader. It uses more energy to transmit messages to the sink. The chain length