CASPIAN JOURNAL

MANAGEMENT AND HIGH TECHNOLOGIES

Read Moskvin Alexander A.  // Caspian journal : management and high technologies. — 2018. — №1. — pp. 40-55.

Moskvin Alexander A. - Head of department, JSC "Corporation" Kometa ", 5 Velozavodskaya St., Moscow, 115280, Russian Federation, moskvin375@rambler.ru

Providing reliable information exchange at presence of interferences in communication channels is a key factor of ensuring successful functioning of automated control systems. Message transmission in data networks is usually done in the form of "pieces of information", i.e packages. To identify successful passing of each package one usually includes a checksum into each transmitted package, which is calculated according to certain rules. While processing information at the receiving side coincidence of the transmitted checksum and the checksum of the received package is checked. If there is such a coincidence an acknowledgment on successful reception of the package is transmitted to the sender. Traditionally, information exchange in control systems and data transmission networks is modeled based on absorbing finite Markov chains. The article presents the rules for constructing matrix of transition probabilities of Kolmogorov-Chapman equation of absorbing finite Markov chain describing the process of transmitting message packages in the data transmission system, providing information exchange by the protocol of data link layer of X.25 type. Description of a process of transmitting each package with arbitrary number of repetitions of packages and acknowledgments transmissions is a feature of the research. In addition, different length of packages, acknowledgments and timeouts in X.25 protocol results in varying length of step-transition in Kolmogorov-Chapman equation. That is why to obtain characteristics of message transmission it is necessary to synthesize step-transition matrix as well. In the research patterns of forming matrixes of transition probabilities and step-transition are revealed on the base of using methods of system analysis. Rules of synthesis for these two types of matrices are formulated on the base of these patterns. We considered using proposed rules for indicating probabilistic and temporal characteristics of different variants of organizing information exchange between links of data transmission system using mathematical tool of absorbing finite Markov chains. It is shown that these rule let form matrices of transition probabilities and step-transition without constructing graph network, what makes the process easier.

Key words: система передачи данных, информационный обмен, системный анализ, звено управления, качество канала связи, пакет, квитанция, вероятность битовой ошибки, требуемое время доведения, вероятностно-временная характеристика, поглощающая конечная марковская цепь,