Head of Laboratory – Dr.Sc. (Tehnology), Prof. Vladimir Vishnevsky

Tel.: (095) 299 2904; E-mail: vishn@iitp.ru

The leading researchers of the laboratory include:

Basic directions of the laboratory activity are related to the development of theoretical foundations for the analysis and synthesis of the information transmission networks as well as to a practical implementation of the large-scale projects concerned with development computer communication networks.

The theoretical researches are carried out in the following directions:

• Simulation and analytical modeling of wireless networks controlled by the distributed and point coordination functions (DCF and PCF) of Radio-Ethernet (802.11 IEEE) protocol.
• Elaboration of the methods and algorithms for analysis of multimedia communications in a packet-switched network (for example, scientific research of IP-telephony and videoconferences);
• Development and investigation of wireless networks based on infrared modems;
• Topology synthesis of distributed information computer networks;
• Methods and algorithms for gateway connection of heterogeneous computer networks;
• Priority routing algorithms for large-scale computer networks;
• Simulation and analytical methods for the network protocols research and optimization.

In 2000 the fundamental researches was going on in the fields of extreme graph theory and queuing networks theory. Moreover, the field experiments with various physical media (fiber-optical, radio and satellite communications), operational environments and various network architecture have to be carried on simultaneously.

• New stochastic queueing models has been developed and applied for investigating a typical broadband wireless network, which is controlled by the distributed and point coordination functions (DCF and PCF) of Radio-Ethernet (802.11 IEEE) protocol and integrates multiple local area networks (LANs), providing them an access to the world-wide area network.
• Basing on analyzing these models, new analytical method has been developed in order to estimate the performance indices provided for abonents of each of integrated LANs. This method allows taking in account of different features of protocol and influences of electromagnetic noise. In compare with simulation, this method time-consuming is small and does not depend on either number of clients in the LANs or average sizes of transmitted files. The numerical results show high accuracy of this method and its good efficiency with solving exploratory problems of radio network design.
• Task of optimal network route choice is formulated for different procedures of the routing, i.e. fixed, alternative, K- way (alternative procedure with restriction of number input lines);
• Efficient calculating algorithms are designed to solve this routing task for the considered procedures. A calculating procedure based on relaxed method of Lagrange has been suggested in order to determine an upper estimate of the fixed routing task solution, this routing task being related to the class of NP-full tasks;
• Complex of programs and algorithms of gateway connection of heterogeneous information computer networks (conformably to gateway connection for “Sirena” and “Express” networks) were developed and investigated here;
• Methods and algorithms for investigation of reliability of distributed information transmission networks were developed here;
• Method for calculating upper and lower estimates of signal information transmission reliability with registration and search of mobile abonent has been developed here. A comparative analysis of signal information transmission reliability has been performed for cases of a distributed and point coordination databases in mobile network.

Theoretical results in the field of the analysis and synthesis of the distributed computer and information networks serve as a basis for developing the large-scale projects, including the following:

• Development of cellular architecture of wireless radio modem network in Moscow for the science and education. The second queue of wireless network Radionet has been realized, including general center of network control and monitoring, which is created at IPPI RAS, and two powerful base stations of speediest connections (radio-cells), which are mounted on buildings of MGU and Presidium RAS. A base station implemented with using captive air balloons has been investigated theoretically and experimentally. A special device of azimuth, horizontal and warm-up stabilization has been designed for this base station. This project realization has given an opportunity to provide a high-speed and inexpensive connection of different scientific and educational organizations to the fiber backbone network in Moscow.
• Development of scientific information computer network in Obninsk. The next stage of scientific information computer network development in Obninsk has been realized by the way of including a new information center. Within the framework of creating computer system, telephone facilities of communication for scientific organizations have been realized as facilities of IP department’s network. This is allows to solve a problem of organizing inter-town phone calls, that is a very important for Academical towns.
• Development of United system for reservation and selling of the tickets on all types of transport for different regions of Russia with using the protocols TCP/IP and X.25. A package of United system software has been designed with the possibility of remote access of terminals through the TCP/IP and X.25 network, which realizes a connection for postal-cash terminals practically in any postal communication branch in Russia.
• Development and extending the information transmission networks of Ministry of the transport RF, Presidium RAS, Federal Road service of RF.
• Development of new version of the automatic document flow system for large management organizations. The system provides:

• realization of distributed technological processes of treating the main flows of the business documents,
• automation of the main stages of preparation and passing of document projects,
• forming the reference-information databases allowing to optimize a procedure of taking the management decisions by the organization management on the base of reliable and operative information.

• Ministry of Industry, Science and Technologies of Russian Federation (State’s contract Num. 203-13 (00)-P): "The development of system of reservation and selling the tickets for all types of transport for different regions of Russia by using protocols TCP/IP and X.25".