A wireless sensor network (WSN) is a network of distributed functionally autonomous sensors that are used to monitor physical conditions of the environment or a geographical location, such as pressure, sound, temperature, etc. and to transfer the sensed data by multiple hops through the network to a central location or sink node. The networks used nowadays are bi-directional, which enables the controlling of sensor activities. The development of WSN was initially motivated due to applicability in military applications like battlefield surveillance but now-a-days such networks are used in various fields ranging from various industrial and consumer applications to industrial processes monitoring to health monitoring at hospitals and so on.

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