IOSR Journal of Electronics and Communication Engineering (IOSR-JECE) e-ISSN: 2278-2834, p- ISSN: 2278-8735. PP 48-53 www.iosrjournals.org International Conference on Emerging Trends in Engineering & Management 48 |Page (ICETEM-2016) Path Selection Using Rendezvous Point Method To Increase The Life Time In Wireless Sensor Networks Sara Baby 1 , Malini Soman 2 1 Electronics and Communication Dep,SNGCE Kadayiruppu,India 2 Electronics and Communication Dep,SNGCE Kadayiruppu,India Abstract :The sink mobility along a constrained path can improve the energy efficient in Wireless Sensor Networks. To address this challenge a proposed method is to form a hybrid moving pattern in which a mobile sink node only visits rendezvous points (RPs),as opposed to all nodes. Sensor nodes that are not RPs forward their sensed data via multi-hopping to the nearest RP node. Fundamental problem becomes computing a tour that visits all the RPs within a given delay bound. Identifying the optimal tour , however is an NP hard problem .To address this problem Weighted Rendezvous Planning(WRP) method is proposed whereby each sensor node is assigned a weight corresponding to its hop distance from the tour and the number of data packets that it forwards to the closest RP.WRP enables a mobile sink to retrieve all sensed data within a given deadline while conserving the energy expenditure of sensor nodes. More specifically, WRP reduces energy consumption and also increases the network lifetime as compared with existing methods. Keywords - Data collection,Mobile_Sink,Scheduling, Wireless Sensor Networks ( WSNs). I. INTRODUCTION WSN have emerged as a new information-gathering paradigm in wide-range of application such as medical treatment, outer-space exploration, battlefield surveillance etc. Each senor node has the capability to collect and process the data, and to forward any sensed data back to one or more mobile sink nodes via their wireless transceiver in a multi-hop manner. It is equipped with a battery, but which may be difficult or impractical to replace, given the number of sensor nodes and deployed environment .These constraints have led to intensive research efforts on designing energy-efficient protocols [5].In multi-hop communication nodes that are near a sink tend to become congested as they are responsible for forwarding data from nodes that are farther away. Thus, the closer a sensor node is to a sink, the faster its battery runs out, whereas those farther away may maintain more than 90% of their initial energy. This leads to non-uniform depletion of energy, which results in network partition due to the formation of energy holes. As the result ,the sink becomes disconnected from other nodes, thereby impairing the wireless sensor networks. Hence balancing the energy consumption of sensor nodes to prevent energy holes is a critical issue in wireless sensor networks. The travelling path of a mobile sink depends on the real-time requirement of a data produced by nodes. For example, in hard real-time applications such as fire-detection system, environmental data need to be collected by a mobile sink quickly. In WSNs with a mobile sink is a fundamental problem to determine how the mobile sink goes about collecting sensed data. One approach is to visit each sensor node to receive sensed data directly [6].This is essentially the well-known Travelling Salesman Problem(TSP)[7],where the goal is to find the shortest tour that visits all sensor nodes .However, with an increasing number of nodes ,this problem becomes intractable and impractical as the resulting tour length is likely to violate the delay bound of applications. Researches have proposed the use of rendezvous points(RPs) to bound the tour length [8],[9].This means a subset of sensor nodes are designated as RPs and the other nodes are simply forward their data to RPs.AS a result the problem which is called rendezvous design ,becomes selecting the most suitable RPs that minimize energy consumption in multi-hop communications While meeting a given packet delivery time .A secondary problem here is to select the set of RPs that result in uniform energy expenditure among sensor nodes to maximize the network lifetime. In this paper ,we call this problem the delay aware energy efficient path(DEETP).we show that the DEETP is an NP hard problem and propose a heuristic method ,which is called weighted rendezvous planning (WRP),to determine the tour of a mobile sink node .In WRP ,the sensor nodes with more connections to other nodes and placed farther from the computed tour in terms of hop count are given a higher priority. Thus, this paper is summarized as follows:  We define the problem of finding a set of RPs to be visited by a mobile sink. The objective is to minimize energy consumption by reducing multi-hop transmissions from sensor nodes to RPs. This also limits the number of RPs such that the resulting tour does not exceed the required deadline of data packets.