Following the recent discovery on the self-similar nature of traffic flowing in high-speed communications networks [Leland, Taqqu, Willinger, Wilson (1993) and Crovella, Bestavros (1977)], much attention was paid on the performance analysis of queueing systems fed by a long-range dependent input process [Willinger, Taqqu, and Erramilli (1996)]. There was a widely-shared feeling, based on the experimental measurements, that an important performance measure of buffer overflow, the overflow probability, decays significantly slower with growing buffer size, under self-similar traffic, than under short-range dependent traffic such as the renewal or Markov-type traffics traditionally used in telecommunication models.
Prof. B. S. Tsybakov (IPPI) and N. D. Georganas (University of Ottawa, Canada) considered a discrete time queueing system which models a communication network multiplexer which is fed by a self-similar packet traffic. The model has a finite buffer, a number of servers with unit service time, and an input traffic which is an aggregation of independent source-active periods having Pareto-distributed lengths and arriving as Poisson batches. The new asymptotic upper bounds to the buffer-overflow and packet-loss probabilities P are obtained. These bounds decay algebraically slow in buffer-size h and exponentially fast with excess of channel capacity over traffic rate. A comparison of these new upper bounds and the known upper and lower bounds is done. The obtained upper bounds give an exact asymptotic of log P/log h when h goes to infinity. The results of the work can be applied to performance evaluation of modern high-speed communications networks.
Cell loss in buffers accessed by traffic sources in one of the fundamental parameters associated with the quality of service in modern broadband communication systems such as the ATM based networks. The quality of service constraint on cell loss is very tight, of the order of 
, which implies that essentially we are dealing with rare events. This has lead to an enormous effort on trying to characterize and study the cell loss phenomenon in queueing systems. There are basically two approaches to this problem: the first is so-called many source asymptotic and the second is the large buffer asymptotic. N. B. Likhanov and R. Mazumdar proved that in the case of the many sources asymptotic if sources have bounded instantaneous rates then there is no change in the form of the tail distribution of the buffer occupancy over the cases when the sources are heavy or light tailed. In both cases the decay is exponential.
N. D. Vvedenskaya was working on the problems of large queueing systems. The fast Jackson networks were investigated. The model of Jackson network is modified to incorporate a principle of dynamic routing between different stations, where each station contains N servers. The tasks can re-enter the system after completing service. In addition N approaches to infinity is performed. This allows to partially solve the modified model, under certain restrictions upon parameters. More precisely, sufficient sub-criticality conditions are given and bounds for the invariant distribution are produced. The limit system presents interesting questions for initial-value problem for a system of nonlinear differential-difference equations. In case of two station system the initial-value problem is solved: the sub-criticality conditions are given.
A review of activities of Russian institutes and companies in the area of CDMA (code division multiple access) systems was prepared by S. P. Fedortsov. The review is submitted to LG Technical Center of Moscow. Multiple access algorithms intended for wireless communication networks were investigated. Particularly a number of random multiple access algorithms providing transmission of multipriority traffic are suggested. For given priority, different characteristics of packet delay as a function of total packet arrival rate are found. Results of investigation are presented in the form of technical reports.
A novel approach to design the storage channel was studed by A. V. Kuznetsov. It is based on a new notion of the structured set partitions (SSP) and multilevel algebraic coding. SSP's with good spectrum of minimum Euclidean distances were designed for different types of Partial Response channels used to model read channel in magnetic and optical disk drives. Bit error rates (BER) of the proposed scheme are investigated for the classical and modified partial response polynomials. Results of simulations show that a gain of 3.5 dB can be achieved for the linear densities 2.8 – 3.2 and bit error rate without using any additional distance enhancing constraints such as d=1, maximum transition run (MTR), or quasi-MTR. Among the completed studies there were the following: constructions of SSP for classical and modified targets, simple sub-optimal decoding schemes, encoder/decoder structures, and analysis of bit error rates (BER) by simulations.
Some special technology for manuscript marks recognition ('Location-independent recognition technoligy') "ORTHOGRAPH" has been elaborated by V. G. Polyakov and his coworkers in the USA. The ORTOGRAPH was patented (V. G. Polyakov, M. A. Ryleev, B. E. Gorbatov. Method and Apparatus for Pattern Recognition and Representation Using Fourier Descriptors and Iteratire Transformation-Reparametri-zation.) of the October of 1999. The rights for its using were bought by the Microsoft.
By I. P. Levshin and I. A. Orlov on a base geometrical optics the phenomena model of the underwater sound signals at a fluctuating ocean was discussed. The dependence of the transport equation parameters and the scattering function of the rays tubes about hydrological and energy characteristics of the ocean media was ascertained. The base algorithms of computation of the random field of the acoustic signals at the point of the resiver was presented.