A thesis for obtaining a scientific degree of the Candidate of Technical Sciences in the specialty 01.05.02 – Mathematical Modeling and Computational Methods. Dnipro University of Technology. National Metallurgical Academy of Ukraine, Dnipro, 2021.
This dissertation work is concerned with the important scientific and applied problem of increasing the quality of functioning of wireless sensor networks (WSN) for energy monitoring and increasing their life time was solved through the development of appropriate mathematical models and methods for studying energy consumption modes.
The analysis of research in the field of building distributed autonomous wireless monitoring systems showed that wireless sensor networks are a promising technology in the field of creating household and industrial data collection and control systems, and the key indicator of WSN that determines their applicability in practice is their lifetime. Based on the analysis results it was systematically substantiated that, taking into account the energy consumption of the data transmission process, the very control of message sizes is the main reserve for increasing the life of devices and the system as a whole, and optimization of the energy consumption of self-powered wireless field devices at the user application level allows the use of transceivers of various manufacturers in data collection and transmission devices.
The work developed a mathematical model of the functioning of large-scale networks based on requests from the wireless sensor network, which made it possible to increase the accuracy of estimating data transmission delays, calculating the power consumption and service life of the network. Relationships are given for determining the transmission time of messages taking into account the network and retransmission delays, as well as the average time spent on the transmission of a frame in conditions of retransmissions. It should be noted that in general, the power consumption of network field devices depends on the characteristics of the hardware, the physical and link layer protocols, the routing protocol, and the network topology. This dissertation work formulates requirements to increase the WSN protection from attacks on field equipment and the system as a whole, which will not only protect the monitoring network, but also increase the guaranteed life of the network.
The SCTMex protocol has been modified. It is encapsulated in the ZigBee transport protocol, which made it possible to increase the level of information security at the level of system field devices. The SCTMex protocol is an extension of the SCTM protocol due to the few initial bytes of the data block.
Analysis of the resistance of wireless monitoring networks to external attacks indicated their critical vulnerability due to the centralized architecture, so the most effective and efficient mechanism for protecting information in wireless monitoring networks is the transition to decentralized systems, including those based on blockchain technology. It is concluded that the most acceptable solution for WSN is a service or private blockchain, which allows the identification of field devices under the control of designated users.
In this work, a computer simulation of a wireless sensor network was carried out using the XCTU 6.3.5 platform for XBee/RF solutions from DIGI Int. This platform allows not only to perform all the module settings, scan a network of any configuration, but also perform network testing with the measurement of specific signal levels and delays that occur.
A specialized software and hardware platform “Smart Utility Web” based on the XBEE S2 wireless module has been developed. The ease of installation of the system hardware and the reliability of data protection ensure a high level of data reliability and performance. By managing block size and encryption at the user application level, you can achieve optimal power consumption in terms of system lifespan while maintaining the required level of quality of service.
Keywords: wireless sensor network, energy monitoring, critical infrastructure objects, mathematical model, power consumption, protocol.
