LABORATORY 5

Laboratory of Teletrafic Theory

Head of Laboratory – Dr.Sc. (Technology) Sergei Stepanov

Tel.: (095) 299-94-15; E-mail: stepanov@iitp.ru

 

The leading researchers of the laboratory include:

 

Dr.Sc. (Techn.)

A. Kharkevich

Dr.Sc. (Techn.)

V. Ershov

Dr.Sc. (Math.)

 I. Tsitovich

Dr.

V. Naumov

 

DIRECTIONS OF ACTIVITY

 

The laboratory deals with the development of teletraffic theory and its applications in telecommunications and computer systems. The following problem areas and models are studied at the laboratory in 2001:

·        the construction of numerically optimized algorithms of calculation the performance measures of queueing models described by multi-dimensional Markovian processes.

·        the development and analysis of teletraffic models for performance evaluation of new cost-effective telecommunication systems.

·        the development of the software tools based on the efficient algorithms to support the performance modelling of the teletraffic models.

·        the construction of the asymptotically optimal procedures for the sequential design of experiments for statistical problems related to telecommunication networks.

·        the analysis of switching systems and interconnection networks for telecommunication and multiprocessing systems.

 

main results

 

Model that trace complex type of the input traffic in digital hybrid systems mixing preemptive wideband and queueable narrowband calls is developed. Model considered can be used for description and evaluation of performance measures of telecommunication system when mixture of real time traffics of interactive communication (either audio or video) and best efforts data (traffic obtained from World Wide Web or in the process of updating or safeguarding data bases) are transmitted. Algorithms for approximate evaluation of performance measures of such traffic system are obtained. The approach is based on the realization of decomposition principle. Constructed models can be analyzed by algorithms that are easy to implement and provide good loss estimate over a wide range of structure parameters. (S. N. Stepanov, E. O. Naumova, E. I. Melik-Gaikazova.)

Optimized versions of well known recursive algorithms designed for estimation of performance measures of multirate models that appear in description of common sharing of bandwidth by a number of MPLS connections are derived. The optimization is achieved by truncation of the state space which allows us in the process of calculation to leave out of considerations the states with negligible small probabilities. Modified algorithms are stable and solve dimensioning problems for large values of bandwidth considerably faster. (S. N. Stepanov.)

It is constructed asymptotically optimal sequential strategy for hypothesizes testing for markov chain’s distributions when the maximal probability of error tends to zero. An asymptotic lower bound is derived involving second additive term for the mean length of the strategy for discrimination between two statistical models for Markov chains. Applications of this strategy for asymptotically optimal detection of abrupt change of the transition matrix and control’s observations were investigated. (I. I. Tsitovich.)

The different broadcast interconnection networks was considered. Different networks with fanout property was investigeted. They are: strictly broadcast switching modules, strictly rearrangeable switching modules with added switches, networks with added looping paths, and networks with fanout and R-nonblocking switching networks.Those broadcasting switching networks on number of crosspoints, design complexity and connection property are considered. (V. A. Garmash.)

The singularities of a filtration at analog-digital transformation at shaping channels in a multi-channel transmission system, when number of channels N³2, are researched. It is shown how it is possible to decrease to an admissible level influence of distortions in an analog low-pass filter without application of phase correctors. For this purpose it is offered to arrange an analog filter passband inside frequency area consisting not only of transmission region of the lowest channel but also portions of transitional and transmission regions of subsequent channels. Necessary guard band between the lower frequency channel and consequent channels is ensured with the digital filter with linear phase response. (A. A. Vitkova, A. D. Kharkevich.)

The architecture of Active router was developed based on Linux OS kernel and architecture proposed by IEEE Working Group P1520.3. The Active router will consist of the core, building blocks, building blocks API and services implemented as Active applications. The Active router core is base software component, which adds to plain Linux OS kernel ability to deal with P1520 abstractions and interfaces. (B. A. Naumov.)

A problem of integrated multiservice maintenance efficiency for users of different types on corporative network was investigated. Digital communication system with steady-state heterogeneous Poisson stream of calls coming on each link is analysed. The numeral results both of link trasmission capacity and grade of sevice for two cases of network resources integration and its segregation were obtained which allowed to estimate efficiency of integration concerned with chennal bunch capacity. It was investigated also the efficiency of analytical describtion of statistical measuring data in Internet. It was showed that application of high order polinomial regresion gave acceptable coordinate both analytical data and statistical measuring data. (V. A. Ershov, O. F. Sergeeva.)

New model of a network node was suggested. The node saves product form of network state probability density function. Service discipline is processor sharing sevice of customers in a last batch with flexible batch bounds that is a natural generalization of the processor sharing discipline with arbitrary distributions of customers service times for customers of different types. The parameters of the node functioning depend as on discrete components as on continuous ones. The product form of the network state probability density function was derived. (O. V. Ivnitski.)

 

GRANTS FROM:

 

·        Russian Foundation of Basic Research (№99-01-00386): "Methods for optimization of performans measures estimates for models of large telecommunication networks with product form of solution" (head S. N. Stepanov).

·        Russian Foundation of Basic Research (№01-01-00287): "Non-parametric hypotheses testing with guaranteed decision rule and its applications" (head I. I. Tsitovich).

Publications in 2001

 

Articles

 

1.      Степанов С.Н., Иверсен В.Б. Способы уменьшения объема вычислений при расчете моделей  систем связи с потерями, основанные на  игнорировании маловероятных состояний // Проблемы передачи информации. 2001. Том. 37. № 3. C. 82-95.

2.      Иверсен В.Б., Степанов С.Н. Оценка характеристик передачи многопотоковых моделей с фиксированным числом повторений // Автоматика и телемеханика. 2001. № 5. С. 105-115.

3.      Лагутин В.С., Костров В.О., Степанов С.Н. Повышение эффективности использования цифровых линий на сетях связи // Аналитический и информационный журнал Документальная Электросвязь. 2001. № 6. С. 7-14.

4.      Stepanov S.N., Lagutin V.S., Kostrov V.O. Performance Analysis of Multiflow Models with Reservation Mixing Preemptive Wideband Queueable and Narrowband Calls // Pr. IEEE/ICC2001 St.-Petersburg International Conference on Communications. Russia. St.-Petersburg. June 11-15, 2001. P. 101-106.

5.      Stepanov S.N., Lagutin V.S., Iversen V.B. Performance Analysis of Traffic System with Access Control Mixing Preemptive Wideband and Queueable Narrowband Calls // Pr. ITC Specialists Seminar on Access Networks and Systems. Spain. Girona. April 25-27, 2001. P. 207-214.

6.      Kostrov V.O., Lagutin V.S., Stepanov S.N. Approximate Methods of Analysis Telecommunication Systems with Reservation Mixing Wideband and Narrowband Traffics // Pr. International Symposium on Problems of Electronics, Informatics, Computer Systems, Networks ICS-NET. 2001. Russia. Moscow.

7.      Вильк Г., Пшеничников А.П., Степанов С.Н. Построение и анализ модели совместного обслуживания речевых сообщений и данных на сетях с линейной структурой // Сборник депонированных работ. Московский технический университет связи и информатики. 2001. 31 с.

8.      Вильк Г., Степанов С.Н. Алгоритмические методы оценки показателей совместной передачи нагрузки на сетях с линейной структурой и коммутацией пакетов // Сборник депонированных работ. Московский технический университет связи и информатики. 2001. 26 с.

9.      Malyutov M.B., Tsitovich I.I. Asymptotically Optimal Discrimination between Markov Chains // In A. Atkinson et al eds. "MODA 6 – Advances in Model-Oriented Data Analysis". Physica-Verlag., 2001. P. 163-170.

10. Malyutov M.B., Tsitovich I.I. Adaptive Discrimination Between Markov Chains // In G. Govaert, J. Janssen, N. Limnios eds. "Applied Stochastic Models and Data Analysis ASMDA 2001". Compiegne. 2001. V. 2. P. 723-727.

11. Malyutov M.B., Tsitovich I.I. Sequential detection of an abrupt change in a Markov chain distribution // In S. M. Ermakov, Yu. N. Kashtanov, and V. B. Melas eds. Proceedings of the 4-th St.-Peterburg Workshop on Simulation. St.-Petersburg, Chemistry research institute, St.-Petersburg university. 2001. P. 334-337.

12. Malyutov M.B., Tsitovich I.I. Second Order Optimal Sequential Discrimination Between Markov Chains // Mathematical Methods of Statistics. 2001. V. 10. No. 4.

13. Кондрашев А.С., Огурцов А.Ю., Ройтберг М.А., Цитович И.И. Поиск локальных сходств в геномной ДНК на основе явно сформулированных статистических гипотез // Сборник отчетных материалов по государственной программе "Геном человека". М.: ИМБ АН РФ, 2001.

14. Голышко А.В., Ершов В.А., Цыбаков В.И. Оценка эффективности введения интеграции на корпоративной сети // Вестник связи. 2000. № 10. С. 99.

15. Голышко А.В., Ершов В.А., Цыбаков В.И. Оценка качества обслуживания пользователей Интернет, включенных в электромеханические АТС // Вестник связи. 2000. № 12. С. 70.

16. Голышко А.В., Ершов В.А., Цыбаков В.И. Оценка эффективности интеграции разных видов обслуживания на корпоративной мультисервисной сети // Электросвязь. 2000. № 12. С. 16-19.

17. Ершов В.А., Ершова Э.Б., Щека А.Ю. Метод оценки качества обслуживания на мультисервисной сети с учетом числа пользователей услуг // Электросвязь. 2001. № 8. С. 5-8.

18. Ершов В.А., Ершова Э.Б., Щека А.Ю. Метод расчета потерь вызовов в АТМ-сети при конечном числе источников нагрузки // Электросвязь. 2001. № 9. С. 33-35.

19. Ершов В.А., Ершова Э.Б. К читателям // Электросвязь. 2001. № 9. С. 27.

20. Ершов В.А., Голышко А.В., Цыбаков В.И. Применение полиномиальной регрессии для аналитического представления данных статистических измерений в Интернет // Вестник связи. 2001. № 9. С. 66-69.

21. Наумов В., Самуйлов К., Чукарин А. Об одном подходе к проектированию систем MPLS // Труды международной конференции "Интеллектуальные сети 2001: услуги, интерфейсы, спецификации". М.: MAKС Прeсс, 2001.

22. Naumov V. Distributed Tool for Telecommunication Network Analysis // Proc. Int. Conf. Automatics and Informatics, Union on Automation and Informatics. Sofia, Bulgaria. 2001.

23. Наумов В., Чистохвалов О. Эффективность передачи данных в оптических сетях связи с разделением длин волн // Труды XXXVII Всероссийской научной конференции по проблемам математики, информатики, физики, химии и методики преподавания естественнонаучных дисциплин. М.: Изд-во УДН, 2001.

 

In print

 

1.      Stepanov S.N., Iversen V.B., Kostrov V.O. Optimized Dimensioning of Large Bandwidth Resources Under MPLS Technology // Proc. of Conference "Telecommunication Networks and Teletraffic Theory". Russia. St.-Petersburg (submitted).

2.      Stepanov S.N., Iversen V.B., Lagutin V.S., Kostrov V.O. Modelling Issues of Differentiated Services in MPLS Networks // Proc. of Conference "Telecommunication Networks and Teletraffic Theory". Russia. St.-Petersburg (submitted).

3.       Vitkov M.G., Vitkova A.A. Calculation of transient processes in filters with multiple complex poles of transfer functions // Radio and Communications technology. 2001 (in print).

4.      Vitkov M.G., Vitkova A.A., Kharkevich A.D. Singularities of a filtration withlinear phase response at analog-digital transformation in multi-channel systems // Proc. 1st IEEE International Conference on Circuits and Systems for Communications – ICCSC (in print).

5.      Vitkov M.G., Vitkova A.A. Law of conservation of energy in modern communication circuit // Proc. 1st IEEE International Conference on Circuits and Systems for Communications – ICCSC (in print).

6.      Ершов В.А., Кузнецов Н.А. Мультисервисные телекоммуникационные сети. М.: 2001, 550 с. (в печати).