Taranenko Vera

Faculty: Computer Sciences and Technologies
Speciality: Information control systems

Theme of master's work:

Prognostication of telecommunications equipment failures.

Leader of work : associate professor Svetlichnaya Viktoriya Antonovna

Abstract

         Telephone communication is the main way of telecommunications, which uninterruptedly and quite intensive by grows as the basis for many other types of communication. That’s why a particular attention is constantly devoted to development, improvement, planning, projecting and forecasting of telephone communication nets. Consequently, it is very important to correctly debug all the regimes of active state of the equipment, which works in real-time, with regard to complex telecommunicational nets of especially large size.

         The aim of this research consists in the formation of the algorithm of prognostication of telecommunications equipment failures.          To achieve this aim the following tasks are to be solved:

         1. to analyse the structure of the object, analyse equipment failures;

         2. to identify the laws of the failures occurrence;

         3. to investigate the opportunity of failures description and their characteristics, and choose the characteristic, with the help of which equipment health will be estimated;

         4. to analyse the methods of time series prediction; to choose the method of prediction, which can be used for forecasting the chosen characteristic.

        During the analysis of the legacy of automatic telephone centre equipment failures, the failures can be classified in accordance with the technical equipment of the automatic telephone centre itself. Modern automatic telephone centres equipment can be divided into three principle groups: the equipment of the station, carrier with subscribers, carrier within the automatic telephone centre.

         There is a hot bank of the equipment of the first group within the automatic telephone centre, in case some module or board breaks down, however the probability of such breakdown is quite small.

         The breakdowns of the equipment of the second group are quite easy to eliminate, and they are not dangerous for the whole net of telecommunication.

         As for the third group of the equipment, its breakdown is attended by the string of consequences, the elimination of which requires a lot of time and funds.

         Consequently, the main breakdowns and bugs of telecommunicational equipment happen within so called transportation network, that is within communications channel. Though, certificate index in accordance with State Standard of communications channels is quite high, in practice, as statistics says this index is much lower. Thus the task of registration and analysis of communications channels failures is timely topical.

         Automatic telephone centre is a large and complex system, which requires appropriate modern process of administration and control. The net of the automatic telephone center of Donetsk is one of the biggest in our country, accordingly the load to the net is very large and the breakdowns are unavoidable, that’s why the process of failures registration needs a separate automatic system of control.

         One of the most important arias of work within failures registration and elimination system is the department of the repairing bureau, which directly concerns itself with the registration of the requests, determination of the type of the breakdown, sending of the foremen, accounting reserve equipment. Namely this department is an exchange, owing to which automatic telephone centres of the whole town never loose contact with each other. Recently as a result of appearance of the great number of new means of information exchange, such as global net of the Internet, mobile communication, load to the telecommunicational equipment has considerably grown.

        Correspondingly it is possible to draw a conclusion; that development of this system of repairing control is one of the most important trends in the modern sphere of telecommunication

         The topic “The Investigation and development of the mechanisms of support of reliability in transportation communicational network for the big cities” was considered in V.S. Chepak’s Master paper. S.V. Kotov dealt with the topic “The investigation of the methods of formation and optimization of the regional telecommunicational net structure” D.V. Tkachenko researched the questions of information security reliability in his Master paper «The investigation and development of technical security of the information at the transportational ATM net”

         The questions of prognostication were considered by the following experts: A.B. Bondarenko, S.A. Koshechkin, I.Yu. Sofijskiy. The methods of elimination, failures diagnostics and reliability were investigated in the papers of Igor Panov, A.N. Berlin, Yu. P. Kosinov, I. N. Lipatov, A.A. Romanov.

         Prognostication systems of appearance, diagnostics and elimination of failures are covered in the papers of foreign authors A.G. Kagramanzade, Dr. Rajender Thusu, Team Leader, and Robert Hundyma. And foreign firms also develop software products for failures prognostication of telecommunicational equipment. The largest of them are “RAM Commander” and “iManager”.

         In order to choose and realize the method of prognostication it is necessary to analyses the failures process. In this connection the statistic data about failures from several automatic telephone centres in Donetsk for 5 years were used, wich contain the number of failures per month.
         Within the investigation a number of prognostication methods were analysed:

        1) Holt’s model;

        2) Holt-Winters’s model;

        3) Taylor-Wage’s model is a complicated Holt’s model, which considers the seasonal prevalence and additive trend. Unlike Holt-Winters’s model, it additively includes linear trend. Let the following time series be given: y_i…y_t, y_i € R.

where s is the period of seasonal prevalence, - is the seasonal profile, b_t is the trend’s characteristic, a_tis the prognostication characteristic, without the impact of trend and seasonal prevalence. The choice of the parameters € (0,1) should be experimental, with the use of meansquare error minimization:

        4) The method of exponential smoothing.

        5) The method of moving average.

        6) The method of extrapolation.

         So the following conclusion has been reached, Taylor-Wage’s model, is the most qualified for telecommunicational equipment failures prognostication, due to the fact that the percentage of accuracy during its usage makes up less than one percentage.

         НIn terms of the chosen method the seasonal constituent entry has been defined and the polynominal trend and the model of prognostication have been built up.

         The results of the investigation of bugs of telecommunicational equipment failures enable us do draw the foolowing conclusions:

         1. The development of the given system of failures control is one of the privileged trends of modern sphere of communication.

         2. The departments of repairing automatic telephone centres should be equipped with all the required modern technical equipment.

         3. It will be reasonable to choose the parameter: ‘the number of failures per unit time’.

         4. Taylor-Wage’s model is the most qualified for telecommunicational equipment failures prognostication, due to the fact that the percentage of accuracy during its usage makes up less than one percent.

         5. As follows from the graph of prognostications model, the constructed curves practically coincide, this testifies to the efficiency of the application of this method.

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©DonNTU 2010, Тaranenko V.V.