Wireless Sensor Networks: Applications and Issues

Abstract

In today's scenario, wireless sensor network is one of the most important technologies used. Wireless communications and electronics are now available in low cost, consume less power and provide multifunctional miniature devices which are beneficial for use in remote sensing applications. These factors have improved the viability of utilizing a sensor network consisting of a large number of intelligent sensors, enabling the collection, processing analysis and dissemination of valuable information gathered in a variety of environments. A sensor network is composed of a large number of sensor nodes which consist of sensing, data processing and communication capabilities. Sensor network protocols and algorithms must possess self-organizing capabilities. One important characteristic of sensor networks is that protocols and algorithms used in it are self-organizing which means that each sensor node is independent and creates it own infrastructure according to different situations. Another unique feature of sensor networks is the cooperative effort of sensor nodes which means instead of sending the raw data to the nodes responsible for the fusion, they use their processing abilities to locally carry out simple computations and transmit only the required and partially processed data. Sensor networks are predominantly data-centric rather than address-centric. So, sensed data are directed to an area containing a cluster of sensors rather than particular sensor addresses. This cluster may contain redundant data. To reduce redundancy and increase the level of accuracy, aggregation is performed. This can be done using the aggregator node within the cluster which further reduces communication bandwidth requirements. A network hierarchy and clustering of sensor nodes allows for network scalability, robustness, efficient resource utilization and lower power consumption. The fundamental objectives for sensor networks are reliability, accuracy, flexibility, cost effectiveness and ease of deployment.