IJSRST162658 | Received: 28 Nov 2016 | Accepted: 05 Dec 2016 | November-December-2016 [(2)6: 321-331] © 2016 IJSRST | Volume 2 | Issue 6 | Print ISSN: 2395-6011 | Online ISSN: 2395-602X Themed Section: Engineering and Technology 321 Survey on Wireless Sensor Network with their remaining Challenges Pavankumar Naik 1 , Nagaraj Telkar 2 , Kiran Kotin 3 1,2 Department of Computer Science & Engineering, SKSVMACET, Laxmeshwar, Karnataka, India 3 Department of Electronic Communication & Engineering, SKSVMACET, Laxmeshwar, Karnataka, India ABSTRACT The wireless sensor network (WSN) is a combination of sensing, computation, and communication into a single tiny device. A sensor network consists of an array of numerous sensor networks of diverse types interconnected by a wireless communication network Sensor data is shared between these sensor nodes and used as input to a distributed estimation system. The system extracts relevant information from the available data. Fundamental design objectives of sensor networks include reliability, accuracy, flexibility, cost effectiveness, and ease of deployment. Each node has at least a sensor with an embedded processor, and low power radius. It acts as information source, sensing and collecting data samples from the environment. Node can also act as information sink, receiving dynamic configuration information from other nodes or external entities. The end portion of a node can be an antenna. A chosen configuration is the microstrip structure which allows for planar circuitry to be integrated with the WSN node. WSNs use small, low-cost embedded devices for a wide range of applications. They do not rely on any pre- existing infrastructure. The WSNs need not communicate directly with the nearest high-power control tower or base station, but only with their local peers. In this paper we have discussed related to WSN,sensors, criteria to choose a sensor, classification of sensors, sensor utilization and also we have discussed about some real WSN applications with their remaining challenges. Keywords: Wireless sensor network, Sensors, Classification of Sensors, Real sensor applications and challenges. I. INTRODUCTION Wireless Sensor Networks A Wireless Sensor Network (WSN) is by hundreds of small, low-cost nodes that are fitted with limitations in memory, energy, and processing capacity. In this particular form of networks, several problems is to learn each node. Recent advances in wireless communications and electronics have enabled the roll-out of low-cost, low-power and multi- functional sensors that are small in dimensions and communicate in a nutshell distances. Cheap, smart sensors, networked through wireless links and deployed in vast quantities, provide unprecedented opportunities for monitoring and controlling homes, cities, along with the environment. Furthermore, networked sensors use a broad spectrum of applications within the defense area, generating new capabilities for reconnaissance and surveillance and various Tactical applications. Self- localization capability can be a highly desirable sign of wireless sensor networks. In environmental monitoring applications for example bush fire surveillance, water quality monitoring and precision agriculture, the measurement data are meaningless lacking the knowledge of the placement from the location where the data are obtained. Moreover, location estimation may enable many applications for example inventory management, transport, intrusion detection, road traffic monitoring, health monitoring, reconnaissance and surveillance. Why we Use Sensors A sensor is a device that detects and responds to some type of input from the physical environment. The specific input could be light, heat, motion, moisture, pressure, or any one of a great number of other environmental phenomena. The output is generally a signal that is converted to human-readable display at the sensor location or transmitted electronically over a network for reading or further processing.