Vol 15, No 4 (2017)

Articles
SOLUTION FOR THE FUNDAMENTAL MODE OF A STEP-INDEX LIGHTGUIDE WITH KERR NONLINEARITY
Andreev V.A., Bourdine A.V., Burdin V.A., Kubanov V.P.
Abstract
The progress in the development of femtosecond fiber lasers and their applications makes the problem of modeling the high power ultrashort pulses propagation in optical fiber cables extremely important. Modern fiber lasers can generate pulses with a duration of less than ten femtoseconds with a peak power of up to tens GW. At such values of peak power nonlinear effects cannot be ignored. For fused quartz fibers and femtosecond pulse duration it can be assumed that only the Kerr nonlinearity is present. For this assumption the approximate analytical solution for the fundamental mode of an optical fiber with step-index profile was already found. This solution was obtained with Gaussian approximation method and it already takes the Kerr nonlinearity into account. However, it neglects the second degree of approximation, which is unacceptable at peak power values exceeding tens of megawatts. In this paper, we consider a solution that takes into account refractive index dependence on high-order terms of light signal peak power which occurs due to the Kerr nonlinearity. For some optical fibers studied the results of the analysis are presented, showing the dependency of the fundamental mode spot radius and propagation constant on the light signal peak power in the presence of the Kerr nonlinearity. It is shown that, with an error of less than 0.1%, the dependence of the fundamental mode propagation constant on the light signal power can be approximated by a second-order polynomial. For the considered optic fiber samples the values of the approximation coefficients were obtained.
Infokommunikacionnye tehnologii. 2017;15(4):313-319
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INTEGRATED ASSESSMENT OF INFORMATION SECURITY REQUIREMENTS IMPLEMENTATION IN AUTOMATED CONTROL SYSTEMS INTENDED FOR PRODUCTION AND TECHNOLOGICAL PROCESSES
Vasilyev V.I., Vulfin A.M., Guzairov M.B., Kirillova A.D.
Abstract
The goal of this paper is the further development of the mentioned approach in the form of engineering technique of evaluating the information security requirements fulfillment in automated systems using fuzzy logic methods and expert estimates. The procedure of determining the level of significance (criticality) of processed information on the basis of fuzzy rule set which accounts for possible detriments caused by violating the integrity, availability or confidentiality is proposed. After determining the information significance (criticality) level and the corresponding system security class, the evaluation of the real system security level compliance to the requirements established by the Federal Service of Technical and Export Control Order No. 31 is performed. These requirements determine the basic set of organizational and technical measures of information protection for each class of the system security. The local and group completeness indices are calculated using experts polling method according to the recommended measures of information protection. In addition to the obtained estimates of the group indices, the integral estimates of information security requirements fulfillment characterizing the average value and the spread in the values of the group indices are shown. The example illustrating the specifics of applying this technique to designing the secured automated control system is considered.
Infokommunikacionnye tehnologii. 2017;15(4):319-325
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REMOVAL OF IMPULSE NOISE FROM IMAGE USING MEDIAN FILTERS WITH WEIGHTED CENTRAL ELEMENT
Chervyakov N.I., Lyakhov P.A., Orazaev A.R.
Abstract
This paper shows the use of median filters with weighted central elements for removing the impulse noise from the image. The influence of the probability of obtaining undistorted pixels and distortion of the image pixel distribution function on the processing result is shown. It is demonstrated that median filters with a 3x3 window allow to obtain a higher quality of image denoising at low probability of impulse noise, and median filters with window sizes of 5x5 and 7x7 allow to obtain a higher quality of image denoising at high probability of impulse noise. The obtained results can be used in medical image processing and adaptive filtering systems for photo and video data processing.
Infokommunikacionnye tehnologii. 2017;15(4):325-337
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SECURE DATA TRANSMISSION OVER SPECIALIZED FIBER-OPTIC LINK
Bourdine A.V., Gubareva O.Y., Pashin S.S., Pugin V.V.
Abstract
In this article we present an alternative method of secure data transmission over physical layer for the “first/last mile” segment of intra-corporate network implemented with specialized fiber-optic link. Proposed solution is based on using few-mode optical fibers with specific refractive index profile as an “encryptor”, which creates unique distortions in accordance with its unique differential mode delay. Therefore, transmitted traffic becomes strongly distorted and cannot be processed without corresponding “decryptor” which might be either another optical fiber with “inversed” refractive index profile in relation to the “encryptor”-fiber or electronic dispersion compensator device modified for such an application. We also propose to utilize elements of mode division multiplexing technique as an additional protection for secure data channel. Such an approach is based on using only one particular mode (or modes) for secure data transmission, which is changed with certain time interval according to the privacy key. This work presents configurations of proposed “crypto-fiber-optic” link as well as the list of problems which require a solution for designing, developing and implementing the presented approach.
Infokommunikacionnye tehnologii. 2017;15(4):337-349
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ENERGY SAVING POTENTIAL ESTIMATION FOR TDM-PON
Roslyakov A.V.
Abstract
Energy saving in the information and communication technology field is an important problem identified while designing Future Networks. To reduce energy consumption, it is important to analyze it at each stage of the lifecycle. In case of networks the in-use mode is primarily considered because energy consumption in this mode is usually the major issue for always-on network equipment. The energy consumption of this mode can be controlled by network architecture, capabilities and operations. The article describes the method of measuring power consumption of passive optical network (PON) equipment with time division multiplexing (TDM). Analysis method is based on the ITU Recommendations Y.3021 and Y.3022. Evaluation of potential energy savings is performed for the Gigabit Passive Optical Network equipment of Eltex Russian company using sleep and cyclic sleep modes. The results of the analysis show that the power consumption of the passive optical network can be reduced to 30% when using sleep mode and up to 50% in cyclic sleep mode with an average network load.
Infokommunikacionnye tehnologii. 2017;15(4):349-354
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REDUNDANCY OPTIMIZATION FOR PACKET-SWITCHED NETWORKS
Troshin A.V.
Abstract
Traditional protocols that are often used for providing redundancy in modern packet-switched networks (Spanning Tree Protocol, Rapid Spanning Tree Protocol, Multiple Spanning Tree Protocol) are very inefficient because they prune links from the network topology in order to achieve a single spanning tree topology. In this paper a method of redundancy optimization for packet-switched networks is presented, based on using non-equal spanning trees of the network graph in order to resolve paths of packets between the switches. The use of non-equal spanning trees enables to get more paths for traffic balancing. Moreover, a proposition is made to connect making of spanning trees with the role of network switch. After that the balancing of network traffic can be optimized by linear programming methods. A practical example of optimization redundancy is shown.
Infokommunikacionnye tehnologii. 2017;15(4):354-360
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OPTIMISING H2/M/1 SYSTEM CHARACTERISTICS CALCULATION
Tarasov V.N., Bakhareva N.F., Kartashevskiy I.V., Lipilina L.V.
Abstract
Currently, there are no analytical methods for precisely determining the characteristics of queuing systems G/M/1 or G/M/m, and this lowers the degree of adequacy of stochastic network models to real computer and telecommunications networks and the quality of design decisions. This article shows the comparative results presented in various publications devoted to the calculation of the average waiting time in queuing systems G/M/1, in particular queuing system with hyper-exponential arrival rate. The results under consideration were obtained by completely different approaches, but the final calculated results are completely identical. These approaches have certain advantages to each other. Using of the analogues simplifies calculation of the characteristics for the system considered, and the author’s approach expands the possibilities of calculating characteristics in terms of determining higher-order moments for the waiting time, which allows extracting information needed to calculate a jitter, for example. Considering the definition of jitter in telecommunications as the spread of the waiting time from its average value, knowledge of higher order moments for the waiting time makes it possible to obtain the jitter value via calculating the variance, i.e. second moment of random waiting time.
Infokommunikacionnye tehnologii. 2017;15(4):360-365
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ON AES STANDARD IMPLEMENTATION FOR CORPORATE NETWORKS
Sakit Gambay oglu S.G., Nagiyeva A.F.
Abstract
In this article corporate information protection by data encryption is considered. For plaintext encryption the usage of Rijndael algorithm is proposed. The algorithm operates on sequences of blocks called “states”. Encryption involves four transformation stages named as follows: SubByte, ShiftRows, MixColumns and AddRoundKey. In the article an example of AES encryption of a typical plaintext representing a corporate mail is shown. It is confirmed that ciphertext length (160 bytes) is almost the same as plaintext length (159 bytes), which corresponds to the requirements. Field test results show the advantages of the proposed encryption method for telecommunication systems with limited computational capabilities.
Infokommunikacionnye tehnologii. 2017;15(4):366-370
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GENERALIZED APPROACH TO BUSINESS PROCESS ESTIMATION BASED ON PROCESS MINING TECHNOLOGY
Budarevskiy I.S., Grishakov V.G., Loginov I.V.
Abstract
In the article a method of estimating business process for a telecommunication company is proposed. The method is based on process mining technology, which allows to identify ineffective operations using logged data. The article reviews the basic steps of estimating a technological process: creating the model of the process and the reference model, testing the model, formalizing the requirements and performing quality estimation. Identification is performed by the decision tree, which is built automatically using machine learning methods. It is shown that the new method allows to decrease the amount of diagnostic operations needed for analyzing a technological process.
Infokommunikacionnye tehnologii. 2017;15(4):371-379
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MODELING OF EXPECTED UTILITY FUNCTIONAL OF ORGANIZATIONAL AND TECHNICAL TYPE SYSTEMS
Maslov O.N., Frolova M.A.
Abstract
The article deals with the results of computer simulation of expected utility functional, which is used as a selection criterion in the management of complex systems (SS) of organizational and technical type. The one-factor and two-factor model of expected utility functional, designed for a wide range of applications, are presented in the article. The one-factor model of expected utility functional is used to predict the effectiveness of economic projects. This model has two variables: deterministic and stochastic, and two undetermined parameters. The two-factor model is needed to solve problems in which the components of expected utility functional are expressed in unequal relative terms: for example, in monetary units and points. This model has two stochastic variables and two undetermined parameters. Both models are focused on the management of complex systems, using the statistical simulation modeling by the Dimov-Maslov method and a computer version of the Monte Carlo method. The article presents the results of the test study of both models of expected utility functional by the statistical simulation modeling .
Infokommunikacionnye tehnologii. 2017;15(4):379-388
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IMAGE SEGMENTATION USING CLUSTERIZATION
Loshkarev A.S.
Abstract
Threshold based methods are the most frequently used methods of image segmentation due to their intuitive nature and ease of implementation. In this article, we consider methods of automatic threshold selection, as well as methods for threshold adjustment in accordance with local image properties. The studies were conducted using Matlab software. Global threshold processing cannot produce the desired result if the image background is highly heterogeneous in brightness. In such cases, it is necessary to apply pre-processing to compensate for variations in background brightness, after which a global threshold transformation can be performed. One way to choose a threshold is to visually examine the image histogram. If the histogram has two distinct modes, then it is easy to choose the threshold separating them. Another approach to threshold selection is based on the trial and error method, when different thresholds are selected and checked until the result of the threshold processing satisfies the requirements.
Infokommunikacionnye tehnologii. 2017;15(4):388-393
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FUNCTIONAL CAPABILITIES OF MODERN EQUIPMENT FOR PACKET MILLIMETER-WAVE RADIO COMMUNICATIONS
Klyuev D.S., Korshunov S.A., Sitnikova S.V., Sokolova Y.V., Platonov S.E.
Abstract
The article gives an overview of the functional capabilities of modern equipment for packet radio communications of the millimeter band. Practical usage examples of the equipment in the conditions of urban environment are presented. Advantages of using this equipment for telecom operators are given. Specific features of millimeter radio waves propagation in the atmosphere and the influence of precipitation, such as rain and snow, on the signal propagation range are indicated. The specifics of the radio channel capacity dependence on the signal bandwidth are indicated. The role of modulation type and gain factor in successful use of XPIC technology with the equipment studied is described. A multifactor analysis of the world and Russian manufacturers of packet radio communications equipment of the millimeter band was carried out. As a result of the analysis, the following characteristics were compared: maximum channel width, maximum signal propagation delay, modulation types used, equipment throughput, range and overall dimensions of the antennas. The main advantages and disadvantages are noted. The article makes some recommendations on the use of equipment models presented in the analysis. In this paper, we have analyzed a number of sources over the past five years. The legislative basis for the use of this equipment on the territory of the Russian Federation is indicated. The prospects of development of packet radio communication systems of millimeter band are described.
Infokommunikacionnye tehnologii. 2017;15(4):394-402
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NOISE IMMUNITY CHARACTERISTICS OF COOPERATIVE ANALOG RELAY IN A VANET NETWORK
Eliseev S.N., Shanturov E.M.
Abstract
Today the capabilities of intelligent transport systems are largely determined by the characteristics of the hybrid wireless vehicular ad hoc networks (VANET). These networks use orthogonal frequency-division multiplexing (OFDM) technique for direct communications between vehicles as well as communications between vehicles and stationary infrastructure devices. Connections can be direct or they can be relayed by means of cooperative diversity when it is needed to improve noise immunity. One of the specifics of the vehicular ad hoc networks is the presence of high-speed vehicles, for which the Doppler spread results in the lost orthogonality of the OFDM signal and interchannel interference which decreases the noise immunity. The article considers the impact of the interchannel interference on the noise immunity of OFDM system using analog relay based cooperative diversity with two vehicles. Fading is modelled individually for each of the OFDM signal subcarriers using baseband equivalents and Rayleigh statistics. Doppler spread model corresponds to isotropic scattering. Keywords: cooperative diversity, AF relay, Rayleigh fading, spectral Doppler spreading, SEP
Infokommunikacionnye tehnologii. 2017;15(4):402-408
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STATISTICAL CHARACTERISTICS OF RADIO WAVES FIELD IN OFFICE ROOM
Kubanov V.P., Kustova M.N., Maslov O.N., Stepanova N.V., Shatalov I.S.
Abstract
The paper presents the results of an experimental study of the electromagnetic field (EMF) levels inside a multi-storey office building. Histograms of Cartesian orthogonal components, modules, and spherical angular characteristics of the electric and magnetic field strength vectors are presented. The Rode & Schwarz spectrum analyzer FS300 is used as a measuring instrument equipped with small vibrator and loop antennas. The measurements were carried out at frequencies of 49,75 MHz and 56,25 MHz and heights of 1 and 1,7 m and the observation point was located above the floor of a rectangular room of 48 square metres. The data obtained can be used as a basis for solving a wide range of applied problems with statistical simulation method: from ensuring the safety of EMF-based workplaces to creating EMF-channels for leaking of confidential data.
Infokommunikacionnye tehnologii. 2017;15(4):409-415
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ITERATIVE PROCEDURES APPLICATION FOR IMAGE SCALING
Ganin D.V.
Abstract
Forensic examination often involves studying various kinds of images obtained from various sources. One of the tasks assigned to an expert is to enhance image quality to obtain visually distinguishable forensically significant details, such as registration plate number or appearance details of a vehicle or a person. In the article an expert assessment of the obstacle influence on recognizing of a registration plate number is presented and the limitations for initial image quality are outlined. Furthermore, a modified image recovery algorithm is introduced for reconstructing fragments of small images, which allows to obtain additional forensically significant data.
Infokommunikacionnye tehnologii. 2017;15(4):416-422
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TEACHING MODERN ELECTRONICS AND ELECTRICAL CIRCUIT DESIGN IN THE FIELD OF TELECOMMUNICATIONS AND BROADCAST TELEVISION
Galochkin V.A.
Abstract
In the article topical issues of teaching the basics of electronics and electrical circuit design in the field of telecommunication and broadcast television are considered. Significant scientific discoveries were made in the field of microelectronics during the last third of the 20th century, and the content of existing courses needs to be changed accordingly. Entirely new technologies and materials were developed and a new scientific direction was formed - nanoelectronic. The technological advance is evident when considering a modern transistor: carbon nanotube used in modern non-volatile memory chips is an example of an advanced technology, as well as memristor, used in neural networks of a new type. Teaching the details of these new methods and materials is not possible within a University course. However, it is suggested by the author that at least the basic knowledge of these novel technologies should be included in a content of modern electronics and electrical circuit design courses.
Infokommunikacionnye tehnologii. 2017;15(4):422-427
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