Dmitry Kozyrev

Comparative Analysis of Reliability Prediction Models for a Distributed Radio Direction Finding Telecommunication System

We consider the problem of reliability assurance of a local ground-based distributed radio direction finding system (RDFS), which consists of a local dispatching center (LDC) and unattended radio terminals (URT), which are up to several hundred kilometers apart from the LDC and are connected to the LDC via communication channels. The performance criteria of the RDFS are defined according to its topology and structure. Requirements on the mean time between failures (MTBF) and the availability factor are imposed. A methodic has been developed for determining the reliability parameters both in approximate analytical form and in the form of a formalized simulation model that takes into account different hierarchy levels of the system from the topology of the network and communication channels to the printed board assemblies and individual types of electronic components. Simulation and calculation of reliability measures was performed using an automated system for reliability calculation of electronic modules and reconfigurable manufacturing calculation (ASONIKA). The weak spots (least reliable elements) of the RDFS have been revealed and recommendations were given to ensure the reliability of individual elements and the RDFS as a whole. The composition of spare parts for LDC, URT equipment and communication channels is proposed.

On Sensitivity of Steady-State Probabilities of a Cold Redundant System to the Shapes of Life and Repair Time Distributions of Its Elements

The problem of sensitivity of a redundant system’s reliability characteristics to shapes of their input distributions is considered. In Efrosinin and Rykov, Information Technologies and Mathematical Modelling, 2014, [1] an analytical form for dependence of a two-unit cold standby redundant system reliability characteristics on life and repair time input distributions was obtained and investigated for the case of exponential distribution of one of the time lengths. In the current chapter this study is extended with the help of simulation method to a general case of both non-exponential distributions. Comparison of analytic and simulation results was carried out.

Analysis of Renewable Reliability Systems by Markovization Method

Markovization method is used for heterogeneous double redundant hot standby renewable reliability system analysis. The time dependent, stationary and quasi-stationary probability distributions for the system are calculated.

Methods of Performance Evaluation of Broadband Wireless Networks Along the Long Transport Routes

This paper presents the description of the method of performance evaluation and assessment of main characteristics of broadband wireless networks with linear topology, which is based on a model of stochastic multiphase queueing systems with correlated MAP input flows and a cross-traffic. The results of analytical calculations for the networks of small dimension are given. A simulation model for assessment of performance characteristics of large-scale wireless networks with linear topology is developed.

Redundant queuing system with unreliable servers

We consider a two-channel queuing system with unreliable servers which fail alternately for modeling of hybrid communication systems, which have a millimeter-wave (71-76 GHz, 81-86 GHz) radio channel as a backup communication channel. The stationary distribution of the system states and the most important performance characteristics were obtained.

New Generation of Safety Systems for Automobile Traffic Control Using RFID Technology and Broadband Wireless Communication

Broadband wireless data transmission network for providing of automobile transport system safety is considered. The network operates under IEEE802.11n-2012 protocol that guarantees high-speed transmission of multimedia information between automatic stationary and mobile systems of traffic control. The model of stochastic network with dependent service time for the problem solution is used. Based on product form representation of the steady state probabilities of such system the formulas and algorithms for calculating the main system characteristics such as: mean marginal queue length and mean sojourn times in the nodes, as well as mean packages delivery time in the whole network are proposed. Results of some numerical experiments are presented.

Reliability-Centric Analysis of Offloaded Computation in Cooperative Wearable Applications

Motivated by the unprecedented penetration of mobile communications technology, this work carefully brings into perspective the challenges related to heterogeneous communications and offloaded computation operating in cases of fault-tolerant computation, computing, and caching. We specifically focus on the emerging augmented reality applications that require reliable delegation of the computing and caching functionality to proximate resource-rich devices. The corresponding mathematical model proposed in this work becomes of value to assess system-level reliability in cases where one or more nearby collaborating nodes become temporarily unavailable. Our produced analytical and simulation results corroborate the asymptotic insensitivity of the stationary reliability of the system in question (under the “fast” recovery of its elements) to the type of the “repair” time distribution, thus supporting the fault-tolerant system operation.

Methods for architecture synthesis of broadband wireless networks with linear topology

A novel iterative algorithm for designing the architecture of broadband wireless networks along the long highways is considered. The mathematical problems were formulated and solved for every step of the iterative method. An example is given of designing a broadband wireless network along the highways in one of the regions of Russia.

Mobility-Centric Analysis of Communication Offloading for Heterogeneous Internet of Things Devices

Today, the number of interconnected Internet of Things (IoT) devices is growing tremendously followed by an increase in the density of cellular base stations. This trend has an adverse effect on the power efficiency of communication, since each new infrastructure node requires a significant amount of energy. Numerous enablers are already in place to offload the scarce cellular spectrum, thus allowing utilization of more energy-efficient short-range radio technologies for user content dissemination, such as moving relay stations and network-assisted direct connectivity. In this work, we contribute a new mathematical framework aimed at analyzing the impact of network offloading on the probabilistic characteristics related to the quality of service and thus helping relieve the energy burden on infrastructure network deployments.

Multi-state Diagnostics for Distributed Radio Direction Finding System

We consider a distributed Radio Direction Finding System (RDFS) and the structure of its hardware. A classical diagnostic model of the distributed RDFS according to the binary criterion is presented, which includes diagnostic graphs and a set of tests. We propose a theoretical basis for diagnosing of the distributed RDFS according to the n-dimensional criterion. An example of implementation of the diagnostic approach to the distributed RDFS for states “failure”, “deterioration”, “normal” is presented.