Cooperative Clustering Algorithms for Wireless Sensor Networks
Hui Jing, Hitoshi Ai · InTech eBooks · 2010
1.1 Wireless sensor networks Wireless sensor networks have been made viable by the convergence of micro-electromechanical systems technology, wireless communications and digital electronics (Akyildiz et al., 2002). They are expected to consist of a large number of inexpensive sensor nodes, each having sensing, data processing and communicating components with limited computational and communication power. To provide various measurements such as light, temperature, pressure and activity, these low-cost, low-power, multifunctional sensor nodes have been widely deployed in a vast variety of environments for commercial, civil, and military applications such as surveillance, vehicle tracking, climate, etc.. However, a single sensor’s view of the environment is restricted both in range and in accuracy, due to it only covers a limited physical area and may produce noisy data by the quality of the hardware. Accordingly, aggregation of the individual surveillance allows users to accurately and reliably monitor an environment. Once sensor nodes are deployed throughout an area, they collect data from the environment and automatically establish dedicated networks to transmit their data to a base station. The nodes collaborate to gather data and extend the operating lifetime of the entire system. Wireless sensor networks offer a longevity, robustness, and ease of deployment that is ideal for environments where maintenance or battery replacement may be inconvenient or impossible (Hac, 2003). In recent years, with the rapid development of embedded systems including energy efficient devices, hardware/software co-design and networking support, sensor nodes have been smaller in size and more efficient in data processing and transmission. However, they are still limited in power, memory and computational capacities. As a result, the key challenge is to maximize the lifetime of sensor nodes due to the fact that it is not feasible to replace the batteries of thousands of nodes.