The Wireless Sensor Network (WSN) scheme is now widely used in industrial and governmental sectors for applications such as monitoring industry machinery, agriculture, and automated medical health devices. Since time synchronization is an essential technology for achieving temporal consistency and security in WSN, technologies such as GPS (Global Positioning System) and NTP (Network Time Protocol), have been used for this purpose. While these synchronization techniques are still widely used today, drawbacks associated with these methods, such as power supply constraints and node synchronization errors, limit the potential of WSN. WSN systems in current use have limitations due to the following:
(A) Accurate synchronization of the data from each sensor node can be interrupted by environmental factors;
(B) GPS signals are not available in underground or underwater environments; and
(C) Energy is required to generate radio waves.
GPS signals are capable of great accuracy, however, GPS signals can be easily blocked by walls, mountains, trees and other obstructions, and cannot reach WSN sensor nodes in underground or underwater environments. In areas where GPS signals are not available, Wi-Fi is a commonly used alternative; however its speed and unreliability can compromise the accuracy of the time synchronization of the sensor nodes. Moreover, Wi-Fi requires power sources to generate the radio wave signals.
CTC has been designed to contribute to solving problems (A)-(C).
CTC utilizes cosmic ray muon muons, a ubiquitous and abundant natural resource particle probe. CTC offers more flexibility, accuracy and application possibilities for WSN networks. The following are the advantages of the CTS method:
(A): Besides the fact that muon particles are almost unaffected by most environmental changes and are capable of penetrating through most natural/man-made environmental obstructions, the muons themselves can be used for time synchronization which drastically improves the accuracy.
(B) It is possible to use WSN in underground and underwater environments due to the muon’s strong penetrative characteristics.
(C) Since cosmic ray muons are created naturally, the particles do not have to be artificially generated.
In the future, CTC has the potential to expand the use of WSN for new applications that are not possible in other ways. For example, it could be used to monitor the structural integrity of an airplane simultaneously at several different points during its flight. It could also be used to monitor the environmental conditions of an underground mine or to a network that consists of smart sensors equipped with buoys, ocean bottom seismometers, and underwater/surface vehicles that are adapted to communicate cooperatively through wireless connections.
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