Vol 14, No 1 (2016)

Nowadays aviation requires global information support that is practical problem. We propose to solve it by using satellite systems in aircraft telecommunications that will provide connection of separate aircraft network to united airspace network. This work presents developed model of described network solution to estimate its potentiality. Here satellite telecommunication system based on S-Aloha protocol is network core that unites aircraft networks CSMA/CA. Proposed model takes into account network interconnection by Mesh technologies. We tested model behavior dependence on the main parameters of airspace and satellite telecommunication networks. Simulation results showed that Mesh technologies provide network bandwidth enhancement over ten times and reduce message delay during transmission. Effectiveness of Mesh technologies using depends on ratio of connectivity of the airspace network segments and external traffic parameter. We demonstrated application of developed model for solution of aircraft special telecommunication network upgrading and modernization problem.

Nowadays fiber Bragg gratings (FBGs) are widely used in various devices and applications of fiber optics. They become a basic component for fiber optic sensor networks. The most of those both commercial and prototype fiber optic sensor systems are based on well-researched either singlemode or multimode regime of signal transmission over optical fibers. However some works are concerned with researches of FBGs written on silica multimode optical fibers (MMF) for various photonics and fiber optics applications. Thus, FBGs written on graded-index MMFs are used in optical filters of fiber optic data transmission systems 10G designed for local area networks and radio-over-fiber systems covering micro- and pico-cells. Some works are focused on FBGs written on step-index MMFs. Slanted or tilted multimode FBGs are also widely used in vibration, temperature, deformation etc. fiber optic sensors. Another group of publications is devoted to conventional FBGs on silica telecommunication graded-index MMFs 50/125 as well as 62.5/125 and experimental approbation of various fiber optic sensors based on them. However, the most part of mentioned papers are focused on just analysis of FBG spectral response during laser-excited optical signal propagation that corresponds to a few-mode regime. Few-mode regime adds a new another one dimension to parameter space that is associated with guided modes of particular order which limited number (from two to a few dozens) transfer the most part of optical signal power over tested optical fiber. Optical fiber operating in a few-mode regime of data transmission is interferometer that in combination with FBG can be considered as an alternative basis for design of elements with new unique properties. This work is concerned with experimental researches of few-mode regimes of FBG operating during transferring of laser based optical signals. We tested FBGs written on silica graded-index multimode fibers 50/125 Cat. OM2+/OM3 with Bragg wavelength 1550 nm by using them in a set of developed experimental schemes based on excitation of multimode fibers by corresponding laser sources. The researches were also focused on analysis of both spectral and pulse responses under changing of selected mode mixing and power diffusion processes due to tension and/or stress local and distributed action to FBG or sensor fiber. Results of spectral and pulse response measurements at the output of schemes with installed described FBGs are represented.

This work presents solution for problem of synthesis of linear modulator and demodulator for linear filtered telecommunication channel with additive noise by root-mean-square criterion. We estimated technical effect of derived solutions obtained for case of transmission of one-dimensional two-way amplitude-modulated signal that demonstrated energy gain to widely used modal modulation. According to the obtained results, we have found there is a stability threshold, and mean square deviation grows exponentially for linear methods of modulation beyond it.

Horizontal drilling is impossible without measure while drilling and logging while drilling (MWD-LWD) systems. Telemetric systems differs by transmission medium that can be wired, hydraulic, acoustical, electromagnetic, or combined of them telecommunication channel with its own merits and demerits. The main demerit of electromagnetic channel is low noise immunity that leads to problem of bit rate enhancement, and large variety of disturbers with their parameters, limiting important factors such drilling depth, accuracy and rate of drilling. This work presents results of development and realization of error-correcting coding signal for MWD-LWD systems. The tests were produced for both urban area and real drill site. In addition, comparison results for offered and conventional device manufactured by LLC "TechGeoBur". During the experiment following units "noise immune coder" of transmitter and "demodulator - decoder" of receiver were modified. Correct test requires comparison of reading been coded by different codes under the noises with the same probability parameters and the same channel distortions. Therefore, a new format of data frame was designed to solve this problem. Conclusive comparison results are represented in table where various reliable values of telemetric parameter "Gravity Toolface" are shown.

The most known methods focusing on matching problems consider counters, which are described by just one equation that limits their application for real object profiles. This work presents derivation of algorithm for matching of drill-pipe thread with reference profile and simulation results concerning on accuracy estimation of matching parameters. This problem appears during evaluation of drill-pipe depreciation parameters including thread connection. Proposed algorithm is based on straight-line equations, describing straight-line segments of thread connection, and assembly of points at plane being obtained by profile scanner during measurement of drill-pipe thread. It connects straight-line equations and coordinates of points, that is described by by transform matrix (offset and rotation matrix). Solution is led to system of nonlinear equations, which is solved by iteration method. During simulation, we researched impact of Gaussian noise to accuracy of matching parameter estimation. Results of measurement are also represented. Approbation of proposed algorithm was realized on real object profile.

This work is concerned with methods for the organizing of the First DVB-T2 multiplex with regional content telecasting insertion over various designs of SFN terrestrial broadcasting digital single-frequency network. We found problem on import substitution of technology for distribution program modification by using replacer because Enensys Technologies is owner of Russian patent of method and device for DVB-T2 broadcasting with regional content telecasting insertion. Disadvantage of used in Russian Federation technical solutions for problem of the First multiplex regional version telecasting is concerned with necessity of coincident T2-MI flow broadcasting in various regions with unified parameters stated by Federal Multiplexing Center. Because it is impossible to set optimal parameters for each region, there is a number of problems of SFN network stability providing, which are defined by bit error ratio. This factor can lead to technical drawbacks and under-utilization of designed network potentialities over bit rate.

Wireless telecommunication systems should be designed for operation over fading radio channels under great variations of environment conditions. An accurate simulation of those channels is required during design and testing of both algorithms and modern radio communication system hardware. This work is concerned on autoregressive channel model of moving average with Rayleigh fading and non-isotropic spectrum of Doppler spread. Proposed model is based on digital autoregressive moving average (ARMA) filter. Simulation uses source filtered complicated white Gaussian noise to produce (approximately) time selective channel process with required non-isotropic spectrum of Doppler spread. This Doppler spread of non-isotropic scattering occurs due to real antenna directional parameters and some reflections along propagation path. We apply infinite impulse response (IIR) low-pass digital filter for approximation of required spectral characteristics and use von Mises distribution for angles of arrival description. Spectral power density of reference model fading process if realized in the form of its approximation by the square of digital filter transmission function with complex coefficients. We focused on estimation of spectrum-shaping filter order and suitable initial approximation for the following numerical solution of Chebyshev approximation problem with reduced number of arithmetic operations produced by this filter.

Innovative development of the University is the subject of careful study today. There is no clear understanding of what it is now. Traditional forms of management do not lead to success. The paper proposes new approach to the University management based on the theory of intersubjective management, which takes into consideration that actors live in different situations and try to find solutions having occured in problem situations. The intersubjective approach to the University innovative development management will enable «ordinary» people in everyday life (students, teachers, service stuff) to engage in the management processes, firstly at schools and Universities, which they represent, and then in society. However, ordinary people do not understand that they can participate in management without relying on decisions of their chiefs and they do not have the methods of intersubjective management participation. Therefore, they should be armed with necessary means, which will give them opportunity to become innovators. In future young specialists educated in such University will be able to engage in the process of society innovative development.