Wireless Sensor Networks Are Defined As The Distribution Of The Sensors

A WSN is a type of wireless networks that consists of collection sensor nodes which are tiny devices. Each sensor node of the network has different processing capability. It may contain multiple types of memory (program, data and flash memories), have a RF transceiver, have a power source (e.g., batteries and solar cells), and accommodate various sensors and actuators. The nodes communicate wirelessly and often self-organize after being deployed in an ad hoc fashion [13, 14]. Optimum need of each sensor node is to maximize its own utility function. Also the whole network requires resource assignments balance to perform in a useful and efficient way. This chapter presents a brief survey on WSNs showing its types, characterizing features, protocols and applications.

Integrity: is to make sure that the content of the information has not been properly adjusted or tampered with.

Authentication: It enables the mobile nodes to ensure the identity of the nodes they are communicating with. With this it provides the secure communication among the nodes. It also helps in identifying the false identity of nodes. This avoids the unauthorized nodes to gain access of the other nodes.

Authentication is the confirmation of a user, typically to ensure that they or their data is authentic, i.e. safe.

Kumar et al. , (2008) classify wireless networks into three taxonomical groups, namely: fixed networks, mobile access networks and ad hoc or mesh networks. The mobile access networks are further divided into the circuit multiplexing (e.g. GSM cellular network), centralized statistical multiplexing (e.g. CDMA cellular networks, IS 95, CDMA 2000, WCDMA and IEEE 802.16 WIMAX networks) and distributed statistical multiplexing (IEEE 802.11 WLANs) (Kumar et al. , 2008). Additionally, they classify ad hoc networks into the wireless Internets and sensor networks ( Kumar et al. , 2008).

Sensor network got tremendous focus due to its less cost and small size and which can be placed anywhere. A sensor network consists of number of sensor nodes dispersed in a specific geographical area. These sensor nodes communicate using wireless transceivers. These networks are widely used

Military Applications: The origin of wireless sensor networks is from defence research, therefore there are vast applications in military where sensor nodes can be deployed in warfield surveillance to detect, locate and monitor enemy activities.

heterogeneous scheme in which all sensor nodes have a different amount of energy as each node is assigned with various task [20] such as SEP[21], DEEC[22]. In this paper, we propose and analyze a novel cluster head selection scheme based on the deployment of nodes in different regions for heterogeneous wireless sensor networks (HWSNs) which is named as RBETSSEP.

The wireless sensor networks have deployed in different data intensive applications including video or audio surveillance, agriculture precision, monitoring of habita. A wireless sensor network with a medium sized can get 1Gigabytes per year from habitat biologically. As the storage capacity is limited for sensor nodes, the data that is excess should get transmitted to base station for analysis and archiving. The sensor nodes should operate in power supplies with limitations like solar panels or small batteries. So that the main problem that is faced by the data-intensive wireless sensor networks is reducing consumption of energy of nodes such that the generated data will be transferred to base

Wireless sensor networks typically consist of a large number of sensor nodes with limited onboard battery resources which are difficult to recharge or replace. Thus the reduction of energy consumption for end-to-end data rate and maximization of network lifetime have become chief research concern. In recent years, many techniques have been proposed for improving the energy efficiency in wireless sensor networks. Among these techniques, V-MIMO technique has been considered as one of the effective ways to save energy. In WSN a node has two communication related energy consuming roles, one role is to serve as a packet generating source node (SN), and the other role is to relay packets for the other nodes, which are both energy consuming operations. This is why the energy minimization is required to extend the lifetime of the WSN.

Nodes location details can be obtained by equipment such as Global Positioning System (GPS) or Bluetooth.

Wireless sensor nodes consists of three pars first one is wireless means without wires second one is sensor mean our nodes or data sensing process third and last one is networks means connection of these nodes to form a network to communicate and report data. When we concern its quality of service it may become too wide part of research so we are promised to work only in energy efficient protocols. The reason behind wireless

A Wireless Sensor Network (WSN) has a large number of energy constrained sensor nodes that have the capability to compute and communicate. They are used to identify the events of interests and transfer the data to the sink node.

A wireless sensor network (WSN) consists of sensing device, computation element, and communication elements that gives user the ability to measure, observe and react to particular events and phenomena in that problem field. A sensing device provides data from sensing physical characteristics such as temperature, pressure and sound etc and then transmits that data to the base station via radio either on time basis or demand basis. A wireless sensor network may contains just a few or large number of wireless sensor nodes, operating in a synchronized and coherent manner to fulfill a common task depending on application.

The wireless sensor networks mainly comprise stationary and mobile sensors that are deployed randomly inside the network and they collect data from the surroundings via wireless communication links [7, 8].