Local clustering and threshold sensitive routing algorithm for Wireless Sensor Networks

Wireless Sensor Networks (WSN) is an excellent technology that can sense, measure, and gather information from the real world and, based on some local decision process transmit the sensed data to the user. These networks allow the physical environment to be measured at high resolutions, and greatly increase the quality and quantity of real-world data and information for applications like environment monitoring. The energy constraint of WSN makes energy conservation the most important goal of routing algorithms. LEACH (Low Energy Adaptive Clustering Hierarchy) is a Proactive protocol and was proposed to organize a sensor network into a set of clusters so that energy consumption is evenly distributed among all sensor nodes. Despite the good performance of LEACH, it has the drawback that the TDMA scheduling assumes that nodes always have data to send. While another protocol TEEN(Threshold Sensitive Energy Efficient sensor Network) proposed for Reactive Networks sense the environment continuously, but transmit data only when a certain threshold is sensed. This protocol is suitable for time critical applications and also is energy efficient because transmission is done less frequently. But the disadvantage of TEEN is that if the thresholds are not reached, the nodes will never communicate, and the user will not get data from the network at all and will not come to know if all the nodes die. In this paper, a hybrid routing algorithm called LCTS(Local Clustering and Threshold Sensitive) is proposed, that takes the advantages of LEACH and TEEN and eliminates its drawbacks. LCTS makes use of symmetric propagation channels where Cluster Head (CH) advertisement heard with the largest signal strength is the cluster-head to whom minimum amount of transmitted energy is needed for communication. The Base Station (BS) selects the Cluster Heads based on location and then the clusters are formed by the Cluster Heads. The nodes communicate with the cluster head in TDMA and send their energy level even if the threshold is not reached and this ensures that the nodes are alive. The sensed data is compressed at the CH and sent to the Base Station.