Design, Architecture, and Security Issues in Wireless Sensor Networks

Introduction

In recent years, advances in miniaturization, yet simple low power circuit design and improved low cost, small size batteries have made a new technological vision possible: wireless sensor network (WSN) (You, Lieckfeldt, Salzmann, Timmermann, 2009). Wireless Sensor Networks (WSNs) are designed by sensor nodes that communicate each other and also processing data and sensing environment (Li & Halpern, June 2001). A conventional Wireless Sensor is illustrated with the help of Figure 1. A sensor node is basically a device that converts a sensed attribute (such as temperature, vibrations) into a form understandable by the users. A functional block diagram of a typical sensor node is given in Figure 2. WSNs, which can be considered as a special case of ad-hoc networks with reduced or no mobility, are expected to find increasing deployment in coming years, as they enable reliable monitoring and analysis of unknown and untested environments These networks are “data centric”, i.e., unlike traditional ad-hoc networks where data is requested from a specific node, data is requested based on certain attributes such as, “which area has temperature over 35C or 95F”. Therefore A large numbers of sensors need to be deployed to accurately reflect the physical attribute in a given area. Due to lack of a better word, typical sensor consists of transducer to sense a given physical quantity with a predefined precision, an embedded processor for local processing, small memory unit for storage of data and a wireless transceiver to transmit or receive data and all these devices run on the power supplied by an attached battery.

Figure 1.

Wireless sensor diagram

Figure 2.

Functional block diagram of a typical sensor node

It is interesting to note that precise specifications of various components, may depend on the type of applications in hand, but the basic characteristics are essentially present to fulfil desired application functionalities. There are few integrated sensors commercially available and can be used directly as plug and play unit to monitor and control some specific physical parameters as decided by the user.

But, there are many basic sensors transducers that could convert many problems quantities such as temperature, pressure, velocity, acceleration, stress and strain, fatigue, tilt, light intensity, sound, humidity, gas - sensors, biological, pollution, nuclear radiation, civil structural sensors, blood pressure, sugar level, white cell count and many others .These basic generic transducers need to be interfaced and connected to other devices and such custom made unit can be used for a given specific application.

Overview Of Key Issues

Lately there has been a developing enthusiasm toward Wireless sensor networks (WSN). Recent headways inside the field of sensing, processing and correspondences have pulled in research deliberations and enormous ventures from changed quarters in the field of WSN. Conjointly sensing systems can uncover previously surreptitiously phenomena. The different zones wherever major research exercises happening inside the field of WSN are:

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  Deployment,

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  Localization,

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  Synchronization,

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  Data aggregation,

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  Dissemination,

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  Database querying,

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  Architecture,

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  Middleware,

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  Security,

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  Designing less power consuming devices,

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  Abstractions, and

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  Higher level algorithms for sensor specific issues.