1. Introduction to Wireless Sensor Networks

At first, the structure of a typical wireless sensor node is described. The operation of each one of the individual units that a wireless sensor node  includes is explained.  The architecture of a typical WSN is explicated. The operation of WSNs is described. The similarities and differencies existing between WSNs and conventional wired networks are expounded. The domains of WSNs ' applications are summarized and characteristic examples are presented.