International Journal of Computer Applications (0975 – 8887) Volume 97– No.4, July 2014 29 Performance Enhancement in Routing using Leach and SAR Protocol Prabhdeep Singh Department Of Computer Science Lovely Professional University Phagwara, Punjab, India Max Bhatia Assistant Professor Department Of Computer Science Lovely Professional University Phagwara, Punjab, India ABSTRACT Wireless sensor network are used to monitor the data and collecting the information. Nodes in network sense the data and collect the data then send it to the base station or the sink. However it requires a high power to send data directly to the sink by all the nodes individually so first there are different type of protocols which are discovered to send the data from nodes to the sensors. LEACH operates on two rounds and the set of node at each round is Cluster nodes (CH). At the end of each round each node that is not cluster head select the closest CH and joins to that cluster head to transmit data. SAR operates for providing the QoS and multiple trees are generated on the basis of energy, QoS and the priority of the packets. The best available path is selected to send the data from nodes to sink or base station. Research is to combine these protocols for reducing overhead of routing tables in SAR and lifetime of the network is increased. The results are compared with the E-LEACH protocol and it is shown that the purposed protocol increase the lifetime of network as compared to E-LEACH. Keywords Wireless sensor networks, LEACH, SAR; 1. INTRODUCTION Wireless sensor network are established for collecting the data and monitoring the information by the sensing capabilities of sensor nodes. In WSN sensor nodes sense the data and collect it then send it to the base station. There are number of sensor nodes in a wireless sensor network which was originally developed for military area where human cannot reach or survive to detect the enemy’s activity. Sensor nodes are of small size computers which act as both to collect the data and as a router for transferring data. There is one high energy node called as base station which acts as a gateway between wireless sensor network and other outer networks. Due to the small size of nodes, each node has limited memory, power, battery, energy etc. So there are number of protocols designed which are applied in the wireless sensor network so that nodes can communicate for last long periods as possible.[1] Nodes sense data and collect it then send to base station. Base station is end terminal for user to collect data from a wireless sensor network. There are number of application for wireless sensor network such as monitoring application for indoor and outdoor environmental, process automation and structural monitoring are included. Tracking application in wireless sensor network is used to track the objects, humans, vehicles and animals. There are following categories of application in wireless sensor network Disaster management, health application, home applications, military applications, traffic control and explosive material etc. Wireless sensor network structure consist three main components:  Sensing field- Area where sensor nodes are deployed to gather the information is known as the sensing field  Sensor nodes- These are the units which gather data and transmit it to base station.  Target- In sensing field target means the node or area from which data should collect. Fig 1. WSN Structure Due to the small size of sensor nodes it is main issue about use of energy that how battery can be saved for a longer period of time and network lifetime can increase. Due to the batteries with limited energy to recharge the batteries again it is difficult to maintain the sensor nodes due to high cost. [1][2] 2. CLUSTERING IN WSN Energy usage is an important issue in the design of WSNs which typically depends on portable energy sources like batteries for power. Micro-Electro-Mechanical System (MEMS) sensor technology has facilitated the development of smart sensors, these smart sensors nodes are small devices with limited power, processing and computation resources. Smart sensors are power constrained devices that have one or more sensors, memory unit, processor, power supply and actuator. In WSNs, sensor nodes have constrained in term of processing power, communication bandwidth, and storage space which required very efficient resource utilization. In WSNs the sensor nodes are often grouped into individual