Synchronization of Measurements in Wireless Sensor Networks
Konstantinos Oikonomou (supervisor)
This doctoral dissertation treats the problem of synchronizing measurements on a wireless sensor network. Specifically, it examines the aspects of the wireless sensor network area and focuses on the development of algorithms to better synchronize the measurements taken by the nodes in order to achieve a more effective correlation and thus better knowledge of the system. In particular, it does not address the problem only from the point of view of the synchronization of the individual sensor clocks, but also from distributed approaches that synchronize the timestamps of measurements taken by the nodes. Synchronization is a crucial factor with a great deal of importance in dynamic and distributed environments. The need for synchronization stems from the dependence of specific systems and subsystems on accurate and accurate data and measurement times, with various protocols and methodologies being proposed from time to time .For these reasons, the concept of synchronization is also important in the case of wireless sensor networks, which are sensitive to environmental changes and are easily affected by many physical parameters, such as temperature. Wireless sensor networks have spread widely over the last decade in many areas of everyday life, life and many activities (eg, monitoring pollution, precision agriculture, etc.), mainly due to the development of low-cost devices implemented by the sensor network. Each sensor node detects some interesting data (e.g., humidity, temperature) and the specific measurements must be are matched to the actual time that took place, i.e., the exact time (timing) so they can be further analyzed and produce reliable analyzes and statistics .The research so far conducted in this PhD thesis focuses in the synchronization of the individual measurements, based on the hops junctions from the sink node, which is responsible for the final collection of all of the measurements. There is already a publication in this context, which deals with the timing of each measurement received from the nodes and their synchronization as they are forwarded to the sink node of the wireless network sensors, so that they can always be correlated and analyzed effectively and valid.