Written by tuzs
You can read the electronic version of the journal issue - Volume 3, Issue 3, 2017.
Contents of the issue
- Andreev V., Bourdine A., Burdin V.
Method for Computing of Precision Positioning Scheme Parameters for MDM Channels Placement on Optical Fiber Core End
- Abstract: This work presents method for computing of precision spatial positioning scheme parameters for mode division multiplexing (MDM) system channels placement on excited optical fiber core end. We demonstrate results of calculations performed for 5-channel MDM system launching into few-mode optical fiber core end with reduced differential mode delay and core diameter 42 m. It is noted that particular combination of injected mode field radius and precision offset provides transferring of the almost total lunched mode power to only one excited desired guided fiber mode with the same azimuth order.
- Keywords: mode division multiplexing, few-mode optical fibers, few-mode regime of optical signal transmission, mode field spatial positioning, differential mode delay, precision offset, mode field diameter, mode coupling coefficients
- Bylina M., Glagolev S., Diubov A.
Comparative Analysis of Direct and Coherent Detection Methods for Digital Information Optical Signals. Part 1. Direct Detection
- Abstract: The paper analyzes the direct detection and coherent detection methods for optical digital signals with various modulation formats: amplitude, phase, and quadrature-amplitude. Signal-to-noise ratios and detectability limts for binary modulation formats were determined. The paper reviews direct detection optical receivers consisting of p-i-n photodiodes and avalanche photodiodes and combination of optical pre-amplifier with p-i-n photodiodes. Block diagrams of heterodyne and homodyne receivers were presented and analyzed.
- Keywords: coherent detection, direct reception, heterodyne receiver, homodyne receiver, single-mode optical fiber, modulation formats, photodetector, optical amplifier, photocurrent amplifier, fiber optic communication system, optical heterodyne, signal-to-noise ratio, detectability, Poisson distribution, Q-factor, phase-locked loop
- Vikulov A., Paramonov A.
IEEE 802.11 WLAN Traffic Analysis
- Abstract: In modern Wi-Fi networks, design and service challenges require accurate estimation of available network resources, quality of service requirements, user quantity and user traffic characteristics. This needs to understand the client device abilities as well as the characteristics of generated traffic. This is not trivial because vendors` recommendations are quite rough. Here is this work, a continuous monitoring of Wi-Fi access network has been carried out, traffic parameters have been gathered and the results of statistical analysis have been presented.
- Keywords: IEEE 802.11, traffic characteristics, Wi-Fi
- Vladimirov S., Kognovitsky O.
Wideband Data Signals with Direct Ternary Maximum Length Sequence Spread Spectrum and their Characteristics
- Abstract: Wideband transmission systems have high noise immunity in white Gaussian noise channel with low signal-noise level. So, the selection of wideband signals and methods of their processing during receiving is relevant objective. This paper reviews possibility of ternary maximum length sequence spread spectrum.
- Keywords: spread spectrum, ternary maximum length sequence, error probability
- Gatchin Y., Demidov V., Dukelskii K., Ter-Nersesyants E.
Quasi-Single-Mode Fibers with Increased Core Size Based on Non-Hexagonal Type Microstructures
- Abstract: The capabilities of silica-based microstructures with a large (40 μm in diameter) core and a non-hexagonal (circular) distribution of voids in the cladding for enhancement of the fundamental (LP01) mode confinement under bent condition are analyzed numerically. It has been determined that the criterion for obtaining a single-mode propagation in such optical elements is a high level of attenuation for the polarization component HE21 of the higher-order mode LP11.
- Keywords: microstructured fiber, large core, single-mode regime, fundamental mode, higher-order mode, optical losses
- Gerasimovich A., Korzhik V., Starostin V.
Investigation of Keyless Cryptosystem Proposed by Dean and Goldsmith
- Abstract: Theoretical and experimental investigation of cryptosystem proposed by two scientists from Stanford University are presented. This cryptosystem has been called in one paper by “revolution” in cryptography. In the current paper it is shown that it is not the case at least in practical application.
- Keywords: physical layer cryptography, fading channel, singular value decomposition, MIMO-systems
- Dvornikov S., Dukhovnitsky O., Fedorenko I.
Dynamic Model of the Vector of Mobile Objects Status for Their Positioning in Wireless Access Networks
- Abstract: The simulation data and the results of a theoretical study on the development of particular models providing the positioning of mobile objects in broadband access networks are presented. The main stages of the development of the dynamic model of the state vector of mobile objects based on passive location methods are given. The results of the development of the analytical apparatus and the carried out simulation are shown, which confirm the consistency of the approach that ensures the accuracy of positioning of mobile objects within 10 meters.
- Keywords: positioning of moving objects; dynamic model of the state vector; processing of radio information; passive location methods
- Elagin V.
Dynamic Load Balancing in Software-Defined Network
- Abstract: In regard with the increasingly complex topology of the network infrastructure of data centers and its requirements of performance, reliability and fault tolerance, the complexity of managing network infrastructure of the data center are also constantly growing. In this regard, there is a need to modification manual configuration of the network infrastructure of data centers by automated means. One of the perspective directions of modernization of the existing network architecture is the concept of SDN. Software-defined data center (Software Defined Data Center, SDDC) is a virtualized structure aimed at providing services. Within this concept it is necessary to develop methods of traffic management and balancing within the data center networks. The article presents a mathematical model of the dynamic load balancing algorithm in data center networks.
- Keywords: Data center, software defined networking, SDN, dynamic load balancing
- Kovalgin Y., Myshyanov S.
174 ... 240 MHz Band Diversification during the Transition to Digital Television and Broadcasting
- Abstract: The article deals with the problems of transition from analogue to digital broadcasting standards in the Russian Federation. There is comparing Russian and European frequency planning in the range of 174-240 MHz. A variant of sharing a radio channel with a width of 8 MHz in the range 174-240 MHz with DAB / DMB and DRM systems due to account the frequency planning adopted in the Russian Federation is proposing. The characteristics of DRM, DAB, DMB systems are given. Links to all modern standards of digital television and broadcasting are given.
- Keywords: digital television, digital broadcasting, DRM, DAB, DMB, radio channel diversification, frequency planning
- Kovalsky A.
Research of Adaptive Multiplexing and Scheduling of the Multiservice Traffic in the Channeling Equipment of Terrestrial Stations of Satellite Communication. Part 3. Scheduling Algorithms
- Abstract: Article is devoted to a question of the organization of adaptive multiplexing and scheduling of traffic of multiservice networks in the channeling equipment of terrestrial stations of satellite communication taking into account the changing interfering situation. Algorithms of scheduling of a multiservice traffic taking into account priorities in service and not stationarity of the incoming information flows are developed. The research of dependences of increase in bandwidth of terrestrial stations of satellite communication on use of technology of statistical consolidation and change of parameters of service quality of a diverse traffic is conducted. Recommendations about upgrade of the channeling equipment of terrestrial stations of satellite communication are offered, and also the model of special program software of the channeling equipment of terrestrial stations of satellite communication is developed.
- Keywords: adaptive multiplexing, scheduling of a multiservice traffic, terrestrial station of satellite communication
- Odoevskiy S., Khoborova V.
Methods of Predicting Self-Similar Traffic’s Quality of Service in Multiservice Network’s Switching Devices
- Abstract: Traffic in modern multiservice networks has features appropriate to self-similar random processes. Analytical and imitation methods, with help of which, data flows’ quality of service in multiservice network’s switching devices can be predicted by index of average waiting time for service’s beginning in different self-similar enter traffic conditions, are conducted in this article.
- Keywords: multiservice network, self-similar traffic, average waiting time
- Simonina O.
The UMTS Load Characteristics Study
- Abstract: The article is devoted to network traffic multimedia service UMTS. The study was conducted using simulation modeling. It is shown that it is critical to increase the share of video traffic over 70%. In the case of simultaneous transmission of streaming traffic and data traffic failure occurs on the access level. With the increase in the share multimedia traffic (voice and stream) a failure occurs on the core network. This study is of interest for the operation of UMTS networks and planning network development.
- Keywords: UMTS, bandwidth, multimedia services mobile network