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 μm. 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.

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.

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.

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.

The capabilities of silica-based microstructures with a large (40 μm in diameter) core and a nonhexagonal (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.

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.

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.

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.

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.

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.

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.

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.