MODELING NONLINEAR ELEMENTS OF CRITICAL COMPUTER NETWORK

• Main Author: Mykhailo Mozhaiev
• Format: Article
• Language: English
• Published: National Technical University "Kharkiv Polytechnic Institute" 2020-12-01
• Series: Сучасні інформаційні системи
• Subjects: critical networks; nonlinearity of oscillation system; equivalent nonlinearity parameter; telecommunications component of computer network; signal frequency stability and robustness
• Online Access: http://ais.khpi.edu.ua/article/view/218838

The subject of research discussed in the paper is indicators of a critical network performance. The research target is a model of nonlinear elements of a critical network. The research objective is creation of a model for nonlinear elements of computer network (CN) telecommunications facilities of a critical system providing the desired parameters of QoS. The paper fulfills the following tasks: analysis of the main factors causing impaired service quality in CN; creation of a model for a small nonlinearity impact on forming free oscillations by generating a relevant motion equation; analysis of oscillator free motion presented in the form of the Duffing equation; working out a general integral of the Duffing equation as applied to a stiff system. The research methods used are: the foundations of the theory of computer systems and networks and the nonlinear differential equations theory. The results obtained are as follows: the main factors presumably causing impaired network services of forensic systems are analyzed; it was found that one of the main causes is the telecommunications component of CN, which possesses a number of critical parameters, including lack of stability and robustness of data signal frequency; numerical simulation of the findings was performed. Conclusions: a formula was devised to define the relationship between the free oscillation frequency and the oscillation system energy with reference to nonlinearity which takes into account the parameters of the oscillation system initial state at startup; nonlinearity of the oscillation system of a self-oscillator has a significant impact on accuracy and stability of its output oscillation frequencies; it was determined that for equivalent nonlinearity parameter values k>0.1 there is a considerable mismatch between the reference signal and the actual signal transmitted in the network, which can cause a large deterioration of  QoS;  further research should be aimed at development of hardware-software tools making it possible to reduce the impact of small nonlinearities of telecommunications equipment elements of critical networks on quality of performance.