Operation Of Telecommunication Systems Research Articles

IMPROVEMENT OF THE METHODOLOGY FOR EVALUATING THE CARRIER FREQUENCY OF THE SIGNAL DURING DATA TRANSMISSION IN TELECOMMUNICATION CONTROL AND DISTANCE LEARNING SYSTEMS

Effectiveness of the application of telecommunications systems is directly influenced by the effectiveness of the functioning of each component and device of its design. The article directly examines the issue of improving the carrier frequency estimation methodology for data transmission in telecommunication management and distance learning systems. The essence of the solution lies in proposals for improving the efficiency of frequency estimation at the input signal synchronization stage, which is presented on the example of a satellite telecommunication control system and distance learning. Namely, the analysis of modern satellite telecommunications systems was carried out and the features that affect the effectiveness of carrier frequency estimation and input signal synchronization were determined. The main inconsistencies are the low energy of the input signal receiving channel, significant signal frequency uncertainty, and the presence of "neighboring channels" receiving the input signal. It was determined that satellite communication systems during data transmission work in the mode with multi-station access in the variant of operation with frequency division of channels, which can receive data packets in the mode of multiple access or when providing a data reception channel on demand. At the same time, the operation of telecommunications systems can proceed both in continuous and in batch modes of receiving the input signal. It is considered that coherent processing of the input signal is carried out in demodulators of satellite telecommunications and interference-resistant coding is used. To solve the task of estimating the carrier frequency of the input signal in coherent demodulators of modern satellite telecommunications, considering the above-defined inconsistencies and features, the article proposes a methodical approach. The essence of this approach is to determine the potential boundary of variances of the obtained estimates of the carrier frequency and to develop algorithms for estimating the carrier frequency of the input signal separately for continuous and batch modes of input data transmission based on the fast Fourier transform. Keywords: Frequency, signal, uncertainty, carrier, estimation.

Analysis and evaluation of efficiency indicators of operation of communication systems station equipment

The mathematical model of process of operation of telecommunication systems with using of the theory of recycling stochastic processes is offered. The indicator of average time of unscheduled removals of systems is defined. Estimates of influence of errors of checking on efficiency of operation of telecommunication systems are given.

B72-19 Future Developments in Telecommunications

J. Martin has succeeded in writing an eminently readable book about telecommunications that is refreshingly different from the usually stuffy textbooks full of technical jargon. Future Developments in Telecommunications is provocative, informative, and will be enjoyed equally by laymen with a passing interest in telecommunications, sociologists who are looking for thought-provoking notions of the effect of future communications on society, businessmen whose future life blood will be at the mercy of telecommunications, and the "experts" in the field of telecommunications, namely the computer users and the communications systems analysts. It is remarkable indeed that a book can be written that would have such a wide audience without becoming trivial to persons actively engaged in the development and operation of telecommunications systems. However, J. Martin has succeeded in one of his aims by demonstrating to nontechnical and technical audiences alike, the catalytic effect that communications presently have on the development of society and how this effect is likely to be magnified in the future, even–to the extent of affecting world prosperity and political systems. He raises many interesting and thought-provoking questions on the social challenges we will have to overcome as telecommunications grinds inexorably forward affecting more and more of the lives of each of us.