Items of № 6, 2011

The Electrosvyaz Magazine is one of the leading science & technical magazines in Russia.


Russian digital multimedia broadcasting system

Some problems have been discussed and results have been reported in this paper concerning the implementation of the Russian national real time audio visual broadcasting system (RAVIS), aimed to sufficiently rise the VHF band spectrum efficiency.A national standard has been created on the base of the development fulfilled and operational test carried out. Sixteen contributions have been made to the ITU-R and CEPT. Key words: ITU-R, VHF, RAVIS, national standard.



Up-to-date high-speed radio relay links

This paper analysis contemporary usage of high-speed microwave systems. Microwave equipment is a key element of transport network in sparsely populated developing areas of Russia. Modified methods of NGSDH on long-haul microwave systems can transmit digital streams to 2 Gbps. Modern technologies are also used pure packet microwave systems. Where because of usage of adaptive modulation technology while packet traffic, availability ratio significantly increases. The analysis, given in present paper should be consider, when new microwave systems is planning.
Key words: High-speed microwave systems, Long-haul microwave systems, NGSDH, Packet microwave systems, Adaptive modulation technology, Availability ratio.



Increasing MIMO systems’ noise immunity practicing antenna autoselection on base and abonent stations

This paper centers on communication system with Time Division Duplex which uses QAM-M signals, KБС antennas on base stations (BS) and KАС antennas on mobile stations (MS) (KАС=1 or 2) for message transmission. It is shown that such a system ensures high noise immunity of signal reception due to the autoselection of the most beneficial combination of one of the Kbs antennas on the base station and the other one Kms on the mobile station. The above system is technically simpler than systems with space-time coding.
The paper covers comparative characteristics of this system and Alamouti system which uses KAM-4 signals, two BS antennas and one MS antenna. It is shown that by increasing diversity order of signals in the presented system it is possible to get rather significant diversity gain as compared to Alamouti system. Given certain transmitted power and satisfaction of signal reception requirements the researched system allows to increase the speed of signal transmission in the communication channel. Key words: KAM-4 signals, BS antenna, MS antenna, Alamouti system.



Analyzing the setup of foreign countries’ spectrum monitoring networks

The statistic data, concerning numbers of monitoring stations of 36 foreign countries and also regional monitoring centers of 20 countries, are considered. Correlation of number of stations and the regional centers with the population and territory of the countries is estimated. Numbers of stations included into the international spectrum monitoring system of the International Telecommunication Union is specified. Regarding 25 European countries the statistics of expenditures of labor on service of the monitoring networks is analyzed. Comparison of the Russian spectrum monitoring network with networks of foreign countries is undertaken on the basis of which the conclusion is drawn on the leading positions of Russia as it concerns an absolute number of stations and a number of stations on 1 million inhabitants. Importance of joining of Russia in the beginning of 2010 to the international monitoring system is noted. Proposals on the further improvement of the Russian spectrum monitoring system are formulated. Key words:  International Telecommunication Union, monitoring networks, service.



System design procedure for 3G networks’ infocommunocation services

The commercial introduction of the global satellite navigation system GLONASS presupposes the attraction of a broad range of developers of info-communication location-bases services (IC-services). The demands of mobility, possible flexible and quick creation of a new services, quality assurances are made to IC-services. At the same time the subscriber location can be determined both the GLONASS devices and several methods of cellular communication depending on restrictions on the required time of calculation and the accuracy (the quality) of location.
Methodology development and implementation of IC-services of 3G networks on the example of location-based subscriber has been proposed. Normalized values of indicators of the quality of the service are criteria for estimating the efficiency of the developed IC-service. Key words:  GLONASS, IC-services, 3G.



Enterprises’ situation centres: information – processes – organization

Discusses the methodological approach to the creation and maintenance of enterprise information management situation centre. The vessel process framework methodology based on the principles of apportionment of liability between zones, their interactions with complex tasks, formalizing the functions performed by automated support systems. The information basis of methodology based on the collection, compilation and structuring information. Structuring information takes the form of a unified situational models, which displays all entities with their relationships, influencing the activity of the enterprise.
Key words: situation centre, information, organization charts, automated system, information and telecommunication system.



Fiber-light guides’ separable optic connectors for control-measuring technique

Fiber optic connectors for measuring technics are investigated.
Key words: Fiber optic connector, fiber optic waveguide for measuring technics.



Technique and facilities for duplex data transmission over fiber-light guides

Fiber optic tapered coupler for duplex communication lines is investigated. This device increase orientation of the light stream and optical isolation of direct and return communication lines.
Key words: Fiber optics, fiber optic tapered coupler, fiber optic waveguide, orientation of the light stream, optical isolation of communication lines.



Implicative approach to the issue of calculating conditional probability and evaluating error probability in digital data transmission path

The probability alteration of uncorrected coding error during the transmission of discrete messages in telecommunication channels and their processing in signal centers under the influence of external destabilizing factors in analyzed. Probabilistic model of hypothetic 64 kb/sec multimodal data transmission path is elaborated. Possibility of using the logical function of implication is studied and the methodology of building-up of implicative form of conditional probability (IFCP) is proved. Mathematical regular (analytical) formulas for calculation of error probability in multimodal data transmission path under the influence of external destabilizing factors are proposed. Key words: telecommunication channels, IFCP, calculation.

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