Радіоелектроніка та телекомунікації. – 2014. – №796
Permanent URI for this collectionhttps://ena.lpnu.ua/handle/ntb/25691
Вісник Національного університету "Львівська політехніка"
У віснику відображено результати досліджень з теорії та проектування радіо-електронних кіл і пристроїв, антен і пристроїв НВЧ-діапазону, систем телекомунікації та інформаційних мереж, а також математичного моделювання та конструювання радіо-електронних схем і радіоапаратури. Для наукових працівників, інженерів та студентів старших курсів, фахівців з радіотехніки, інформаційних технологій та телекомунікаційних систем, матеріалознавства, інформатики, вимірювання і контролю якості.
Вісник Національного університету «Львівська політехніка» : [збірник наукових праць] / Міністерство освіти і науки України, Національний університет «Львівська політехніка» – Львів : Видавництво Львівської політехніки, 2014. – № 796 : Радіоелектроніка та телекомунікації / відповідальний редактор Б. А. Мандзій. – 255 с. : іл.
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Item Багаторівнева модель буферизації даних у вузлах обслуговування мультисервісного трафіку(Видавництво Львівської політехніки, 2014) Климаш, М. М.; Кирик, М. І.; Плесканка, Н. М.; Кагало, І. О.Проведено огляд основних принципів буферизації даних у вузлах обслуговування мультисервісного трафіку. Запропоновано багаторівневу модель буферизації даних у вузлах, які обслуговують велику кількість TCP потоків. Здійснено оптимізацію моделі буферизації з метою забезпечення задовільної якості надання послуг у мультисервісній мережі передачі даних. Given the bursty behavior of cloud applications described above, an easy solution to the incast problem would be to overdesign buffer capacity at each network node. The basic principles of data buffering at the multiservice traffic service node were reviewed. The data buffering multilevel mode in the nodes, that serve a large number of TCP flows, was proposed. Each level of the model has its own characteristics and is relatively independent. However the malfunction of any of them, may adversely excel at the efficiency of other levels. The network interface represents the physical level, which is the lowest. Packets routing are occurs at the protocol level. Two queues provide communication between physical layer (network interface card) and ip module. One is called the backlog and is used for incoming packets, the other – txqueue, for outgoing packets. In the current networks, the basis for data transmission is TCP/IP protocol stack. It provides a set of tools to deliver data from one application to another. Today, the size of the buffers is determined by the dynamics of TCP’s congestion control algorithm. In particular, the goal is to make sure that when a link is congested, it is busy 100% of the time; which is equivalent to making sure its buffer never goes empty. A widely used rule-of-thumb states that each link needs a buffer of size B = RTT × C, where RTT is the average round-trip time of a flow passing across the link, and C is the data rate of the link. Arguably, router buffers are the single biggest contributor to uncertainty in the Internet. Buffers cause queueing delay and delay-variance; when they overflow they cause packet loss, and when they underflow they can degrade throughput. Given the significance of their role, we might reasonably expect the dynamics and sizing of router buffers to be well understood, based on a well-grounded theory, and supported by extensive simulation and experimentation. The Smart-Buffer architecture takes into consideration that congestion in a typical data center environment is localized to a subset of egress ports at any given point in time and realistically never happens on all ports simultaneously. This enables its centralized on-chip buffer to be right-sized for overall cost and power; at the same time, the buffer is dynamically shareable and weighted towards congested ports or flows exactly when needed using self-tuning thresholds. In addition, the centralized buffer can be allocated based on class of service or priority group. Available buffer resources can therefore be partitioned into separate, virtual buffer pools and assigned to special traffic classes. This is especially useful in converged I/O scenarios where some traffic classes (such as storage) may require guaranteed lossless behavior. These properties enable Smart-Buffer technology to strike an optimum balance between silicon efficiency and burst absorption performance – essential design principles in current and next-generation high density. Optimization of the data buffering multilevel model to ensure a satisfactory quality of service in multiservice data network was made in this paper.Item Модель оцінки пропускної здатності когнітивної радіомережі на основі OFDM(Видавництво Львівської політехніки, 2014) Кирик, М. І.; Янишин, В. Б.; Стрихалюк, І. Б.У роботі запропоновано модель взаємодії когнітивної радіомережі з мережею GSM. Для когнітивної радіосистеми пропонується використовувати OFDM для покращення сканування радіочастотного спектра, формування спектра і формування огинаючої OFDM-сигналу в системі когнітивного радіо, а також визначено організацію структури даних вторинної мережі. Запропоновано математичну модель імітації мережі CR з первинною і вторинною радіокомірками та оцінки пропускної здатності системи. Модель імітує діяльність первинних користувачів системи GSM і роботу мережі CR, беручи до уваги умови радіосередовища, розташування CR користувачів та їх вимоги до якості для різних видів послуг. In this paper considered the cognitive radio (CR) networks with the GSM network like primary network cooperation possibility. The cognitive radio system meant radio with a selfmanagement mechanism with different levels of ability to adapt to the changing radio environment. The self-management mechanism is based on the principles of learning and artificial intelligence. In world practice, the frequency assigned to a particular entity in a certain area on a long term basis. However, most commonly frequency for this designated area not always used, and as necessary. In other words, many frequency bands are irregularly loaded in the space and time domains. Because of the shortage of frequency resources are limited to the cellular network to the data rate. The data rate of modern communication systems is also increasing due to the use high-level types of signal modulation, requiring more signal/noise ratio at the receiver input. Existing GSM network is almost completely satisfy the needs of users for voice services, but the data rate cannot compete with cellular networks based on UMTS and LTE technologies. Here proposed high speed data transmitting method in GSM based on the principles of cognitive radio. On the existing GSM network topology (primary/licensed network) complementary superimposed secondary/unlicensed network operating in the same frequency bands. CR system must have ability to measure, sense, learn, and be aware of important operating conditions. It should be able to find and exploit the unused parts of the spectrum at the fastest and efficient way. The popular spectrum sensing algorithms such as matched filtering, energy detection, spectral correlation (cyclostationarity), radio identification based sensing, waveform based sensing can provide awareness of CR system. Moreover, cooperation spectrum sensing can reduce the detection time and increase the agility, but also facilitate the problem of hidden terminal, shadowing or severe multipath fading. Here proposed to use OFDM for the CR system and discussed OFDM’s advantages to allow better sensing and spectrum shaping capabilities, considered OFDM-symbol formation method in CR system and determined the data structure organization. The mathematical simulation model of CR network with one primary system and one secondary cell created for accurate capacity evaluation of selected system. Model simulates GSM primary users’ activity and CR network operation scheme that taking into account the radio environment conditions, CR users location and their quality requirement for different type of services.Item Етапи розвитку сучасних інфокомунікаційних сервісів та енергетична ефективність мережевих технологій(Видавництво Львівської політехніки, 2014) Лунтовський, А. О.; Гуськов, П. О.; Масюк, А. Р.Розглянуто архітектурні перетворення сучасних мереж та їх (мобільних) сервісів і додатків. Подано періодизацію розвитку мережевих сервісів, Internet та хмарних обчислень. Запропоновано заходи, що необхідно вживати, щоб підвищити енергетичну ефективність сучасних технологічних рішень, розбудовуючи телекомунікаційні мережі майбутнього. Описано концепцію та особливості розвитку від “Інтернету людей” до “Інтернету речей” та “туманних” обчислень. Розглянуто розмежування категорій IoT, IoS, Clouds та Smart Grid. Значна увага приділена необхідності переходу до технології Fog Computing. Наведено приклади реалізації енергетично ефективного сервісу типу XaaS на основі мікрокомп’ютерного вузла, а також енергетично ефективного мережевого пристрою пам’яті. The article reviews the architectural transformation of modern networks and their (mobile) services and applications. Periods of network services, Internet and cloud computing are posted. We describe the requirements for telecommunication networks in each of the individual stages of development and performance criteria specified network technologies. The paper presents the measures that should be taken to improve the energy efficiency of modern technology making in the development of telecommunications networks of the future. The concept and features of the evolution from “Internet of people” to “Internet of things” and “fog” computing are described in details. Certain categories distinction has been considered, such as IoT, IoS, Clouds, and Smart Grid. Much attention is paid to the need to transfer to the Fog Computing technology. A realization of energy-efficient XaaS type based on micro computer unit and energy-efficient network storage device is offered. Examples of energy-efficient File Server (Private Cloud Storage) type service Raspberry Pi based on microcomputer unit are shown. It is worth noting that there is some compromise in solutions for Fog Computing / Smart Grid technology development. The choice varies between centralised, often virtualized systems (Clustering, Clouds) and decentralized systems. The paper describes the criteria for selecting between centralized and decentralized systems.Item Аналіз планарних хвилеводів методом збурення(Видавництво Львівської політехніки, 2014) Фітьо, М. В.; Ромах, С. В.; Бобицький, Я. ВВикористано метод визначення сталих поширення планарних хвилеводів за наявності збурення діелектричної проникності. Метод ґрунтується на представленні поля збуреного хвилеводу у вигляді лінійної комбінації полів незбуреного хвилеводу з деякими коефіцієнтами. Проведено розрахунки для хвилеводів, які не впливають на випромінювання (пасивні), поглинають чи підсилюють його (активні). Ця теорія є наближеною, коли враховуються лише направлені моди, проте може бути точною, коли немає взаємодії між модами. One of the important tasks today in the field of communications and information technologies is the ability to provide high-speed data transmission using fiber-optic communication lines. The presence of existing homo- and heterostructures in semiconductor lasers cannot implement this task due to the fact that at high-frequency modulation these structures generate a large number of modes, i.e., wavelengths. As an alternative, distributed feedback lasers (DFB lasers) are used which active medium is similar to a waveguide that includes a periodic structure, namely a grating. A waveguide indicates that active layer has greater refractive index than layers surround it. In a grating which is formed at layer interface of structure, Bragg reflection occurs providing single-mode generation in spite of spatial failure due to a standing wave in active medium. As to the theory of distributed feedback lasers, it is well developed and studied when first order Bragg conditions are carried out. Instead, there is another situation for higher order Bragg conditions (second, third). In particular, the theory for analysis of waveguide lasers to satisfy second order conditions is described, but it is only applied to active waveguides with surface relief gratings; in addition, representation of the fields in active waveguide is not quite complete. Also, the fields are not sufficiently presented for waveguides with bulk gratings resulting radiation is expected only from waveguide top, but at small angles to the axes x (i.e., almost perpendicular to a waveguide) and z (beam generated is propagating in a substrate) it is not provided by the theory. The theory of propagation of plane only reflective wave in periodic medium with gain and without it is worked out, and generation conditions at implementation of second and higher order Bragg conditions are obtained. But there is no possible to use this theory directly for waveguide DFB lasers because it is not clear how fields and waveguide mode constants of planar waveguides are calculated. Therefore, the aim of this work is a usage of method to find propagation constants of waveguide modes at perturbation presence which is determined by change of waveguide permittivity during pumping. This method is based on fact that field of unperturbed waveguide is represented as linear combination of unperturbed waveguide fields with coefficients which depends on coordinate along which waveguide modes propagate. As a result, systems of second order differential equations are obtained. In this paper, both passive\ (permittivity ε(x) is a real function) and active (ε(x) becomes imaginary values) waveguides without grating in a structure are considered. Using both the perturbation method and approach based on Fourier transform, symmetric and asymmetric waveguides are analyzed, and propagation constants of guided modes are found. Good coincidence of results obtained by these methods is observed. Difference is only in last digits of propagation constants; it appears due to rounding. Theory used is approximate because only guided modes are taken into account, but it can be accurate when there is no interaction between modes of unperturbed waveguide.Item Про зменшення громіздкості математичної моделі лінійного параметричного кола(Видавництво Львівської політехніки, 2014) Шаповалов, Ю. І.; Мандзій, Б. А.; Бачик, Д. Р.Досліджено вплив вибору змінних диференціального рівняння, що описує лінійне параметричне коло у часовій області, на зменшення громіздкості такого рівняння. Запропоновано правила формування системи лінійних диференціальних рівнянь кола, що забезпечують її прийнятну громіздкість. In this paper are investigated the influence of variables the differential equation describing the linear periodically time-variable circuits in the time domain on decrease of bulkiness such equation. Rules of forming a system of linear differential equations of circuit that provide its acceptable bulkiness are proposed. Communication of voltages and currents on elements of an electric circuit looks like algebraic, differential and integral equations. As showed computer experiments, on the bulkiness of system of the equations, that describe in particular LPTV circuit and its further transformation in time domain, essentially influences presence of integrated expressions in this system. Since the input and output variables are usually given you must to choose such method of formation of system of equations, which would provide absence in it integral expressions. The first rule of formation of the system of equations of circuit is as follows: to provide absence the integral expressions in the system of equations describing a circle in the time domain, as variables in it need to choose the voltage on the capacitor and current in the inductor. One of the perspective methods of forming of equations is the tabular method. By the tabular method in system of equations as variables are selected nodal voltages, currents and voltages on the elements of the circuit, and the equations themselves may be formulated so that the integral expressions were absent. It follows the second rule of formation of system of differential equations which is as follows: in the absence of other requirements, mathematical model of circuit in the time domain advisable to form by the tabular method that provides absence the integral expressions in equations without additional action to remove them. In addition, the tabular method does not impose restrictions on the structure and elements of circuit. Under condition of performance of the presented two rules the system of the equations describing a circuit less bulky than without it. Normally in such systems variables which do not interest the researcher further are eliminated, and the equation in which there are only two variables is formed. Bulkiness of the last equation too can be different, and it depends on what variables left in it. The third rule of forming a differential equation that describes a circle in the time domain and that provides acceptable bulkiness is as follows: despite the fact which variables of circuit is an output variables, in a mathematical model of circuit that was formed by a rule 2, we eliminate all variables, except what correspond to an input signal and a parametric element. If sources of input signal or parametric elements in the circuit a few then such equations necessary to form few - one for each pair of “input - parametric element.” The differential equation that formed by the three rules using method L.A. Zadeh is transferred into the frequency domain and is solved by the frequency symbolic method. As a result we receive symbolic parametric transfer functions which are a basis for formation of a frequency symbolic model of each parametric element. Such models in turn are a basis for creation of frequency symbolic model of circuit as a whole. Such frequency symbolic model of circuit contains or determines output signals. Values of output signals of circuit may be are converted to the time domain.Item Аналіз структури мережевого трафіку та мережевих аномалій на прикладі сегмента локальної мережі кампусу Національного університету “Львівська політехніка”(Видавництво Львівської політехніки, 2014) Романчук, В. І.; Алексєєв, С. В.; Червенець, В. В.; Колодій, Р. С.Новітні мережі підтримують тенденцію щодо підвищення інтеграції різних типів мережевої інфраструктури і технологій, формуючи так звану концепцію “Інтернету речей”. Це вимагає створення нових підходів до забезпечення безпеки і цілісності мереж, боротьби з мережевими аномаліями. Використання методів “точкового аналізу” трафіку і формування базових принципів, необхідних для створення так званих “розумних мереж”, допомагає наблизитися до відповіді на ці виклики. The main objectives of this article are to analyze and propose new solution to increase network efficiency and security. New approaches to the network designs are emerging with changing of network services and network availability requirements. To create network environment that can fully support ability to freely interconnect between various devices and inside different network types (BYOD (Bring Your Own Device), Internet of Things, etc.), the new mechanism of traffic analysis and control must be developed. When discussing basic principles of this new approach, we need to take in consideration all the major challenges that this “freely interconnected” concepts are facing. The main problem will be network security and integrity. Also significantly will increase percentage of “parasite” network traffic and network anomalies occurrence. But with high traffic rates transmitted over network segments and mobility of network users that are using wireless network infrastructure, current approaches Intrusion Detection Systems (IDS), Intrusion Prevention Systems (IPS), and other network and security monitoring approaches just not flexible enough and inefficient. The future of network security and traffic control solutions lies within “smart network” concept. New types of “smart networks” need to have an ability to react autonomously on any “threat” or anomaly in network flow. This requires an algorithm that can in real time make a correct suggestion regarding current network problems. Basically the whole process will include three stages: monitoring (finding and locating certain network problem and defining its “pattern”), classification (using “pattern” that was established on previous stage classification algorithm can now find suggested source of the problem and mechanism of solving it), resolving problem (finally we can apply solution that algorithm choose to solve the problem). All this stages must be combined in one procedure that is executed by autonomous controlling unit. For decreasing an amount of false positives and information that needs to be proceeded, this control mechanism need to include problem detection solution that will use “critical point” method of information gathering (only collect traces and traffic patterns of certain minimum that needed to identify problem), and machine learning (to dynamically improve quality of selected solutions).Item Метод вибору мережі доступу в мобільній системі SDR при вертикальному хендовері(Видавництво Львівської політехніки, 2014) Глоба, Л. С.; Суліма, С. В.; Курдеча, В. В.Запропоновано метод вибору мережі призначення процедури вертикального хендоверу в гетерогенних мобільних радіосистемах зі здатністю реконфігуруватися, побудованих на основі технології Software Defined Radio: сформульовано задачу вибору мережі та представлено процедуру вертикального хендоверу в таких системах. Змодельовано і проаналізовано процес розв’язання оптимізаційної задачі прийняття рішення про вертикальний хендовер за допомогою системи Mathcad. In order to satisfy emerging user requirements in advanced services/applications, provided seamlessly, operators have to deploy complex network topologies of heterogeneous nature, where different Radio Access Technologies (RATs) co-exist in single composite network with shared resources. Network operator will have assign the appropriate RAT to perform the respective task, so as to achieve the required quality of service, cost-effectively. In such circumstances, there is a need in vertical handover – mechanism of transferring current connections from one radio access network to another. Furthermore, reconfigurable (adjustable) depending on the telecommunication environment devices should be used as user terminals. Software Defined Radio (SDR) technology has been identified as a key enabler of such equipment and networks. This paper is devoted to the vertical handover problem solving. Vertical handover decision problem is very important, because it has strong influence on the network performance and the quality of service of nodes. There are two main aspects of this problem: how to define “best” and how to determine the best access bearer. In the article the access selection method of vertical handover process in heterogeneous reconfigurable mobile radio systems based on SDR technology is proposed: access selection problem is formulated and vertical handover algorithm in such systems is described. To perform an accurate decision the proposed decision process rely on multiple attributes decision-making, while providing a small delay due to the sequential filtration and reduction of the set of possible alternatives. The method allows optimizing network and radio resources utilization and quality of service in heterogeneous network and also provides dynamic adaptation of the access selection decisionmaking rules according to the different telecommunication conditions and network policies. The proposed selection criteria, on the one hand, is simple and well-formalized, and therefore does not require significant computational and time costs, but on the other – provides adaptability. Vertical handover algorithm takes into account peculiarities of SDR devices and therefore can be used in SDR networks. To evaluate the method Mathcad system was used. The effectiveness of the method is confirmed by simulation example for UMTS, GPRS and WLAN networks, which is based on proposed decision-making process where decision is made not on the basis of the absolute advantage of alternative but on the basis of difference between the current and alternative modes parameters, therefore minimizing the amount of intersystem handovers causing additional load on the system. Simulation confirmed that linear aggregation function in multiple attributes decision-making process is the most appropriate because it provides almost the same results as the other methods but in a much simpler way.Item Сеть распределения телекоммуникационных услуг абонентам железнодорожного экспресса(Видавництво Львівської політехніки, 2014) Безлюднов, Д. Э.; Кубасов, И. С.; Сундучков, К. С.Описано напрями розвитку концепції інтерактивної гетерогенної телекомунікаційної системи (ІГТС) і місце супутникового радіоканалу в такій мережі. Показано переваги і недоліки супутникової лінії в архітектурі ІГТС. Розглянуто принципи побудови мережі розподілу послуг абонентам залізничного експреса. Розглянуто сигнал на передавальній та приймальній сторонах. Запропоновано мережу розподілу послуг абонентам експреса. Розглянуто ЕМС системи розподілу інформації від центральної станції експреса до абонентів. This article describes the new concept of providing multimedia services, which require bandwidth 12 Mbit/sec, for mobile subscribers moving at speed of 250-350 km/h on train express. This concept is called – interactive heterogeneous telecommunication system (IHTS). Also describe a place of a satellite channel in this network. There are advantages and disadvantages of satellite trunk line in architecture IHTS are also observed in this paper. We consider the signal at the transmitting and receiving side. Defined restrictions on group channel and OFDM symbol separately. Calculate the following parameters of OFDM symbol that will be used in downlink channel from base station to central station on the railway express: 1. Bandwidth of one subcarrier. 2. Pulse length. 3. Pulse widening factor. 4. Maximum number of services in 400 MHz bandwidth. 5. Maximum number of subcarriers in one OFDM-symbol. 6. Bandwidth of one OFDM-symbol. Also calculated the total number of OFDM-symbols which require for transmit the whole traffic for 200 subscribers. We have composed those OFDM-symbols in 1 GHz group channels and calculate the total bandwidth. We calculate that parameters for 12Mbit/sec for one service and for two hundred subscribers. It is proposed part of the scheme for the receiver of the OFDM signal for central station on train car. Defined the key operations that should be done for receive complex signal. That scheme will receive OFDM-symbols, unpack it, multiplex sub-channels and produce prepared for future distribution services. Also discuss the principles of construction of distribution network services to subscriber’s railway express. Define some key feature of placing routers in the train cars. Proposed 2 different model of distribution network, using Wi-Fi technology, and pros and cons of them are considers. Questions of electromagnetic compatibility for distribution system information from a base station to express subscribers are considered. Problem that reduces the power of the signal at the receiving side are represented. Proposed the following solutions: 1. Use carrier frequency 5 GHz for Wi-Fi 802.11n technology. 2. Decrease radiant power of routers at the central station that transmit signal to routers at train car. 3. Rationally allocate frequencies for Wi-Fi technology. 4. Use a protective coating on the train car roof to reduce the multipath signal. The formula for calculate the length of protective coat from receiver router are offered. 5. Use protective shields on the train car roof to reduce the multipath signal. The formula for calculate the height of protective shields and length, at which the protective shield should be placed from receiver router are offered. Described other possible negative impacts on distribution system.Item Метод згладжування вхідного навантаження на cервер on-line тарифікації(Видавництво Львівської політехніки, 2014) Скулиш, М. А.Запропоновано метод згладжування вхідного потоку заявок на сервер тарифікації, що враховує вимоги до ресурсів кожного з етапів обслуговування заявок, що дасть змогу рівномірно навантажити ресурси системи протягом часу обслуговування заявки. Charging users for a server operator billing involves performing a number of operations. Each service provided by the operator or service provider customers, charged at a separate scheme, as the bottleneck in the process of providing services are bilingual system. Operation performed is limited. In case of exceeding its application is considered lost and the user is notified of the inability to obtain services. In this situation, the operator has monetary losses. In systematic failures in service deteriorates reputation. Therefore, it is important to make a control input streams so as to reduce the possibility of exceeding the service time of the user’s requests. The process of managing incoming applications to the server should consider charging the features of charging large companies: • charging process involves a sequence of standard operations, speed and resources for the implementation of which depends on the type of service that serviced • a variety of services that are billed differently, • extremely high number of requests for billing, • irregularity of the input stream, applications received according to Poisson. Scheme smoothing the input load is a set of values of the maximum number of requests (the sequence {ki}), arriving at the input of the system in a short time interval in a given sequence. Number of elements in a sequence of n is chosen so that the equation was carried out , where t - the average time of the system. It’s necessary to choose a sequence {ki} to satisfy conditions: 1. Applications that are both served by the system must use the volume V of resources close to the total maximum number of resource Vmax. Dispersion sequences such amounts shall be minimized. 2. Dispersion elements of the sequence {ki} should be minimal. The method of solution of choice sequence {ki} by using genetic algorithm. When using the proposed scheme smoothing the input load is provided by the maximum allowable flow uniformity requests. Since overlooked the sequence of operations performed on the application server to the mobile operator, the amount of resource that is required for these operations. Selected sequence of maximum permissible values of number of applications coming into the system in a short period of time.Item Багатоканальна система передачі даних у сплайнових базисах(Видавництво Львівської політехніки, 2014) Кутін, А. І.Запропоновано принцип побудови багатоканальної системи передавання даних з використанням сплайнів та проаналізовано статистичні результати дослідження побудованої моделі. The article deals with multichannel digital data transmission system in which the digital signal is transmitted through the manipulation of the harmonic function which performs subcarrier function with different frequency for different channels. However, so far as the video signal with rectangular shape is characterized by a wide spectrum, the resulting signal also has a wide spectrum, which is not acceptable for most of communication systems with a large number of channels. In order to limit the occupied bandwidth in the filter the Hermitian cubic spline filter’s function is used. The quantity of the points of spline filter is defined according to the task of smoothing of harmonic subcarrier’s sampling frequency of different channels. In this paper an analysis of the amplitude-frequency characteristics of spline filters for oddly even number of points has been conducted and the dependence of the filter’s bandwidth extension with the points quantity decrease has been revealed. Low slope recession and respectively bad filtering of copies of discrete signal are also typical for the spline’s characteristics with the points quantity less than 64. Total signal is the sum of values which come in succession from the interpolators of each of the channels. On the receiving side the separation of channel signals is done by Savitsky-Golay filters. Spline functions which were used for the interpolation on the transmission side (LSS-decomposition) are the basis of given filters. Since the spline filter’s frequency response corresponds in shape to a low pass filter the filter’s bandwidthes with different numbers of points intersect. But that does not prevent the exercise of the corresponding channel selection signal if you follow the order of separation from a more narrowband channel to a more broadband one. For the estimation of stability of the described system of transmission to the operation of additive Gaussian noise and violation of synchronization a two-channel model was built. 128 function points for the channel with higher transmission rate and 512 – for the channel with slower rate were used. The frequencies of the harmonic functions and the sampling frequencies of the channels were selected: F128 = 16 Hz, fs128 = 64 Hz, for a channel with the number of points 128 and F512 = 1 Hz, fs512 = 16 Hz, for a channel with the number of points 512. Shift keying period corresponds to the sine waves period what eliminates the open-phase fault. The results of the conducted analysis show transmission system’s high stability to the noises but low stability to the deviation of synchronization in the form of a considerable growth of error probability to bit.Item Контроль малих деформацій багатомодового полімерного волокна шляхом аналізу спекл-картин на його виході(Видавництво Львівської політехніки, 2014) Варищук, В. І.; Бобицький, Я. В.Запропоновано та розглянуто метод контролю малих деформації полімерного оптичного волокна вимірюванням коефіцієнта кореляції спекл-картин. Досліджено схему та принцип роботи волоконно-оптичного давача деформації на основі багатомодового полімерного оптичного волокна. Проаналізовано залежності коефіцієнта кореляції спекл-картин від параметрів оптичного волокна та довжини хвилі випромінювання. Запропонований метод може бути ефективно використаний для контролю механічних напружень будівель та інженерних споруд. In this paper an optical scheme and the operation principle of strain monitoring based on the interference between guided modes in multimode polymer optical fiber is investigated. The possibility of measuring of the relative strain by processing of speckle patterns at the exit face of multimode fiber is studied theoretically and experimentally. The algorithm of correlation processing of speckle pattern is developed too. The recent progress of polymer technology allowed the application of plastic optical fiber in sensor design. Polymer optical fibers (POFs) have many advantages for sensing applications, including high elastic strain limits, high fracture toughness, high flexibility in bending, high sensitivity to strain. Polymers also have excellent compatibility with organic materials, giving them great potential for structural health monitoring. The most schemes of POF sensors were constructed using single-mode fiber, because it has high technical parameters. But, optical schemes of single-mode POF sensors are very complex. Multimode POF sensor can be constructed using only one fiber and digital camera. This simple scheme is based on the phenomenon of interference between modes in multimode optical fiber. The features of the low cost sensing technique for small strain measuring with using multimode POF were considered. This investigation shows that relative strain of conventional polymer optical fiber can be measured with high accuracy by correlation processing of speckle patterns formed at the exit face of fiber. The correlation method considered in the paper allows one to measure an axial elongation of the fiber within 0 to 50·10-7 m for typical multimode polymer optical fiber with the core diameter 980 μm. The interval between measurements is a few seconds, are needed to stabilize of speckle pattern. The measuring range of such strain sensor depends on properties of fiber used as sensitive element of sensor and using wavelength. The sensitive of sensor is determined by the changes of refractive index and temperature variations due to fiber deformation. Device sensitivity may easily be modified to coincide with required measurement sensitivity through careful choice of the active sensing fiber parameters. The sensing technique presented in this paper is simple, effective and inexpensive solutions to the problem of small strain measurements.Item Теоретичні аспекти та практичні особливості багатокритеріальної оптимізації процесів забезпечення якості реа на стадії виготовлення(Видавництво Львівської політехніки, 2014) Бобало, Ю. Я.; Бондарєв, А. П.; Кіселичник, М. Д.; Недоступ, Л. А.; Тарадаха, П. В.Висвітлені теоретичні та практичні аспекти моделювання та оптимізації забезпечення процесів якості РЕА на стадії виробництва. Описано програмне забезпечення для завдань оптимізації ТП і приклади його застосування. One of the most important scientific and technical problems is to ensure the quality and reliability of technical objects. In this paper the theoretical and practical aspects of modeling and optimization of quality assurance processes of radio electronic equipment (REE) at the manufacturing stage are presented. In modern conditions a hard economic situation of the problem complements the requirement of rational usage of available resources. REE quality modeling requires the accounting of many processes at all life cycle stages (design, manufacturing, maintenance). Such processes form given, required and relevant properties of REE. The problem is solved by the modeling and optimization of technological processes (TP) of REE manufacturing, in particular by optimization of control procedures on technical and economic criterions. Mathematical feature of optimization methods using for such TP is a very large number of parameters. Each of parameters (for example, depth of control at all technological operations (TO)) is vectorial, therefore optimization even in one parameter becomes multiparameter. The adaptation of formal mathematical optimization methods to real processes is an independently, difficult and responsible task. Also in this paper the software (program-methodical complex) for optimization problems of TP and examples of its application are shown. This complex was used to solving problems of modeling, research and optimization of real REE manufacturing processes. This program has been tested on examples of typical manufacturing TP of printed circuit boards with six different technologies, integration chips, the universal oscilloscopes, liquid crystal indicators and other products. Optimization results open the possibility of process control by choosing the optimal (rational) structure, the optimal structure of the system control, formation of appropriate directory of the technological, control and measuring equipment. This generally guarantees the most rational using of all kinds material and technical resources. The results of sensitivity of account technological processes parameters to parameter values of technological operations showed additional opportunities of a program-methodical complex OPTAN on practical results implementation of TP optimization. The received results give the chance by development or upgrade of TP conscious to evaluate risks and the expenses caused by a deviation from best parameters values. These results give opportunity to define the most responsible links of process, quickly to estimate influence of TO parameters correlations of different physical nature on processes expenses of manufacturing and guarantee maintenance.Item Комплексний підхід до підвищення стійкості електронних апаратів домеханічних дестабілізуючих факторів(Видавництво Львівської політехніки, 2014) Матвійків, М. Д.; Матвійків, Т. М.Розглянуто взаємодоповнювальні способи підвищення стійкості електронних апаратів (ЕА) до дії ударів та вібрацій, які за механічних впливів є основними дестабілізуючими факторами. В разі механічних ударів інерційне перевантаження становить 5..15 одиниць. У багатьох випадках верхня границя енергетичного спектра прискорень досягає 50..150 м/с2. Під час ударів і вібрацій в елементах ЕА і, передусім, у контактах виникають незворотні зміни, які закінчуються руйнуванням. Оскільки повністю позбутись впливу механічних дестабілізуючих факторів не вдається, то необхідно приймати рішення про можливість підвищення стійкості електронних засобів. Комплексний підхід означає одночасне застосування декількох відомих засобів підвищення стійкості ЕА до ударів та вібрацій. Дослідження показали, що саме такий підхід дає найкращі результати. The paper considers complex ways to improve the stability of electronic devices (ED) to shocks and vibrations, which are the main destabilizing factors among mechanical effects. In mechanical shock, the inertial overload may reach up to 5..15 units. In many situations, the upper limit of the energy spectrum of acceleration reaches 50..150 m/s2. Such large inertial overload very quickly (in tens or hundreds of beats) causes the destruction of regular ED. Vibrations are general companion of shocks, or may be generated by regular sources, like propellers, moving vehicles or various motor devices - electrical, mechanical or internal combustion engine. In the presence of shocks and vibrations, in the elements of ED and, most of all, in their contacts appears irreversible changes that finally lead to the destruction. Engineers are trying to mitigate the impact of shocks and vibrations. Since the influence of mechanical destabilizing factors on the ED can not be completely solved, it is necessary to make decision on the possibility of increasing the stability of electronic devices. Various studies have shown that a differential approach, that concentrates on the use of only certain types of compensations for mechanical effects, such as shock absorbers, damper pads, various gels - do not give the desired results. At-first, they do not eliminate the influence of mechanical factors completely, and, secondly, they increase the weight and overall indicators of ED. On the contrary, an integrated complementary approach means the simultaneous use of several known means for increasing the stability of ED to highly energetic shocks and vibrations. A complex approach means the simultaneous use of several, supported each other, technical means of increasing the stability of ED to shocks and vibrations. The regular practice is following: ready ED are placed on dampers, matched according to their weight, operating conditions and the nature of mechanical forces, which that reduces the negative effect of mechanical destabilizing factors. The second set of questions concerns the choice of components mounting technics. Currently, for the connection of electrical elements most manufactures use sital, ceramic or polyimide substrates – they have a higher resistance to shocks and vibrations. The results of our research shows that: 1. Drilling columns at low frequency has large amplitude oscillations, and, hence, a wide energy range, which cause rapid destructions, primarily – electronic tools, and drilling telemetry systems, as well. 2.Wide studies have shown that only a complementary approach can improve the stability of ED and provide the best results in case of aggressive mechanical destabilizing factors.Item Особливості планування радіорелейних систем умережах мобільного зв’язку(Видавництво Львівської політехніки, 2014) Семенко, А. І.; Шокотько, А. А.Показано актуальність використання радіорелейних систем у мережах мобільного зв’язку, які дають змогу створювати розгалужену мережу доступу з великою пропускною здатністю і з достатньо гнучкою для зміни топологією без великих втрат коштів і часу. Зазначено, що ефективна робота радіорелейних мереж досягається технічно правильним плануванням обладнання, частот, ємностей прольотів і їх параметрів, забезпеченням прямої видимості прольоту, стійкості конструкції до вітрових навантажень, стабільності електроживлення, мінімальних завад через інтерференцію сигналів у мережі. Підкреслюється здатність радіорелейного обладнання працювати в гібридному режимі з одночасним використанням стандартів PDH/SDH спільно з IP пакетами і цим досягати універсального рішення для передавання даних на рівні доступу мобільних мереж. Showing the relevance of the use of microwave systems in the mobile networks, which make it possible to create developed access layer of the transmission network with large bandwidth and flexibility enough to change topology without great loss of time and money. It’s very actual to use the modern microwave equipment, which works in the range of frequencies, which are called E-band (70-80 Ghz), and it is possible to reach the transmission speed rates up to 2.5 Gb/s. Such transmission speed is enough to satisfy the need not only of 3G base station, but LTE as well. It is noticed, that in the countryside and in small towns concentration of base stations is reduced in comparison with cities, as each station can cover a large area due to fewer obstacles to propagation of radio waves and a low density of subscribers. In such cases, microwave equipment that combines the advantages of low cost and high performance with characteristics that can compete with the wire communications, also is the best solution for the deployment of transmission networks on access levels. It is noted that the effective operation of microwave networks is achieved technically by the correct technical planning of the equipment, frequencies, capacities spans and their parameters, providing direct visibility of the microwave link, stable design of the supporting structure considering its wind loads, power sources stability, minimal losses caused by interfering signals in the network. In the current work the main requirement to the microwave networks structure and performance in the mobile operators transmission networks during the planning and implementation stages are described. The mains point and stages of the microwave transmission networks planning process are listed. The features of microwave transmission systems are described: signal in a radio link can be transmitted with vertical or horizontal polarization, vertical polarization signal is less affected by natural rainfall, but during the frequency planning it is often necessary to use horizontal polarization signal, the microwave stations are commonly used parabolic antennas with aperture diameter up to 2m. Depending on the microwave network geographical position it is necessary to take into the account local terrain and climate conditions, which have strong impact on the microwave links performance and microwave network planning. Also, it is possible to estimate microwave planning quality by calculating special indexes which can show the microwave network work availability, frequency planning efficiency. Emphasized the ability of microwave equipment to work in hybrid mode while using the standard PDH/SDH together with IP packets and thus achieving universal solution for data -level access to mobile networks.Item Система динамічного радіомоніторингу параметрів навколишнього середовища(Видавництво Львівської політехніки, 2014) Стрихалюк, Б. М.; Пелішок, В. О.; Ріппенбейн, В. В.Проведено дослідження систем динамічного моніторингу з відображенням отриманих результатів на виділеному сайті в мережі Інтернет та використанням мобільних вимірювальних пристроїв. Показано, що при цьому виникають дві додаткові проблеми порівняно з використанням лише стаціонарних вимірювальних пристроїв. Для вирішення однієї проблеми – зменшення завантаженості безпровідного каналу зв’язку – запропоновано використання попередньої обробки послідовних результатів вимірювання в мобільних вимірювальних пристроях. Спростити вирішення другої проблеми – зменшення трудомісткості обробки всіх результатів для їх відображення на виділеному сайті – запропоновано забезпечити заміною логічних операцій графічними побудовами з використанням запропонованого методу. The environmental monitoring systems that display the obtained results on a dedicated site in the Internet are considered. The most common systems consist of one or more measuring devices that form the measuring system located in a controlled stationary object. Such objects can be large settlements and ecologically dangerous enterprises. Each measuring device generates data about the coordinates of it’s location (longitude, latitude) and the levels of controlled environmental parameters. Measuring devices transmit preformed information through the main communication channel to the center of data collection and processing. However, the known system monitors only a few fixed points, which may be not enough within the state. There may be cases when the fixed points of the environmental parameters will not exceed the permissible limits but between them the situation could be alarming. Therefore it’s necessary to create a system of dynamic radiomonitoring of the environmental parameters with increased informativeness about points carrying radiomonitoring by ensuring that the system can function not only with stationary measuring devices but also mobile. As a result, there are two problems: a significant increasing of the workload of the wireless communication channel and the increasing amount and complexity of the results of processing in order to reflect them on a dedicated website. Thus it’s necessary significant system improvements. For significantly reduction of the wireless channel’s workload the sequential preprocessing of measurement results in mobile measuring devices is proposed. If some parameters (latitude, longitude and measured parameter) for two consecutive measurements differ slightly, that is within acceptable limits, only label is transmitted that indicates the parameters’ immutability. Then in the data centre according to the brief supplied label the restoration of primary needable to displaying information is done. This dramatically change the amount of information about the results of measurements at a certain time from each of the measuring devices. This system construction requires a single complication of each measuring device, which in general leads to a permanent reduction of the workload of the wireless communication channel. In order to reduce the complexity of processing all the results to display them on a dedicated website offered a replacement logic operations graphical construction. The fact is that for results displaying it’s needable to check each of them for exceeding or not exceeding the permissible level. This test requires the use of logical operations that are quite time consuming, so require certain time costs. Therefore, an important issue is the reduction of the indicated time costs. For the above stated purpose in the data center the advanced data processing is using, which consists in replacing the logic checks by graphical constructions. This construction is based on the use of the proposed method “2D-3D-2D/”.Item Оцінювання взаємоспектральних компонентів періодично нестаціонарних випадкових сигналів(Видавництво Львівської політехніки, 2014) Юзефович, Р. М.Проаналізовано властивості оцінок взаємоспектральних компонентів, що знаходять на основі перетворень Фур’є згладжених оцінок взаємокореляційних компонентів. Виведено формули для зміщення та дисперсії оцінок, що описують залежність цих величин від довжини відрізка реалізації, точки усічення корелограми, форми згладжувального вікна та спектральних характеристик сигналу. Наведено приклад оцінювання взаємоспектральних компонентів амплітудно- та фазомодульованих сигналів. stationarity. In the case of periodically non-stationary random processes (PNRP) correlate harmonics distant one from another on frequencies, what multiple to value T, T - period of non-stationarity [1, 2]. Since faults appearance in rotating elements of mechanical systems leads to periodical non-stationarity of vibration signals when searching of correlations between harmonic components can lay in the base for defects detection [1, 3–5]. For description of such correlations used spectral components, which are Fourier coefficients of varying spectral density and at the same time are the Fourier transformations of correlation components. For widening of vibration diagnostics capabilities reasonable to provide a cross-spectral analysis of vibration signals measured at different points of mechanical system. It gives possibility to investigate spatial properties of signals and to solve tasks of defects localization with higher effectiveness [6, 7]. The properties of cross-spectral components estimators, based on Fourier transformation of smoothed estimators of cross-correlation components, are analyzed. The formulae for estimator bias and variance, which describe dependence of these values on realization length, point of correlogram cutoff, smoothing window form and signal spectral characteristics, are derived. The examples of cross-spectral components estimation for amplitude- and phase modulated signals are given. It is proved that variances of cross-spectral components estimators depend on all of spectral components, which are present in Fourier decomposition of varying spectral density of periodically non-stationary random processes. It is shown that statistical analysis of stationary approximation of PNRP can not be made within stationary model but only within the PNRP, which approximation it is.Item Моделювання каналу Гілберта–Еліота у системі зв’язку CDMA2000 в умовах міської інфраструктури(Видавництво Львівської політехніки, 2014) Вакула, Ю. Я.Розглянуто основні переваги використання алгоритму Гілберта–Еліота для моделювання бітових помилок у каналі зв’язку в мобільних мережах стандарту CDMA2000. Подано характеристику основних чинників, що спричиняють появу бітових помилок, та шляхи їх подальшого математичного моделювання. Розроблено математичний апарат моделі станів для каналу зв’язку із “пакетом помилок” в середовищі програми MatLab 2013 R2. На основі проведених досліджень запропоновано модель зі значним виграшем ефективності порівняно із базовою версією. Any radio channel transferring information is a subject to data corruption. Especially it’s important for 3G mobile networks that use high frequency carrier wave and significantly increased data rate in channel. In this case data loss prediction mechanism gives a lot of opportunities for new network designing as well as for existed network improvement. Statistically a communication channel with error processes can be modelled regarding to one of the predefined patterns which describe particular environment influence on measured parameters of transferred data with a sufficient accuracy. Also some kind of improved models with memory can be implemented for channels where digital packet data are carried. In this paper the main advantages of Gilbert-Elliot algorithm for bit errors simulation in communication channel of cdma2000 mobile network are described. This algorithm is widely used in simulation development of data. The Gilbert-Elliott model is a simple binary case of finite state Markov channel with two states marked as “good” (G) and “bad” (B) states. Each of the states may generate errors with its own error rate eG and eB, respectively. As result it is a binary symmetric channel (BSC) with transition probabilities q to switch over from “good” state to “bad” state and p for reverse transition. The article shows that it’s possible to display error grouping in packets only if transition probability is much smaller than probability to stay in the same state. Otherwise errors occurring will be observed in random ordering. Error possibility in current state depends on the previous state. In that way the channel gets the memory feature. Few external factors can cause data corruption in radio channel of cdma2000 radio system. They are occurred as result of user movement, multi-path propagation, interaction with large obstacles, interaction with other sources of radio waves or noises, etc. It’s free space loss, slow fading, fast fading, interference and noise. Review of these factors that cause bit error occurrence and ways to further mathematical modelling are given. CDMA system involves a lot of recently developed accomplishments in radio engineering and telecommunication areas. It’s the results of impressive improvement of technical characteristics and software acceleration, which moved today cellular systems to absolutely new performance level. But in the same time it requires a professional solution to develop high quality data models. As result a mathematical model of state machine for communication channel with errors burst is developed with MatLab 2013 R2b environment. Simple version of developed model provides good statistical data. But it requires few calculations per each bit of data. It causes a low system performance. Based on the investigation a model with significant performance improvement in comparison with the basic version of model is given.Item Титульний аркуш до Вісника «Радіоелектроніка та телекомунікації» № 796(Видавництво Львівської політехніки, 2014)Item Дослідження оптичних волокон методом цифрової голографічної інтерферометрії(Видавництво Львівської політехніки, 2014) Петровська, Г. А.; Варищук, В. І.; Фітьо, В. М.Запропоновано метод цифрової голографічної інтерферометрії для дослідження фазових мікрооб’єктів. Створено макет голографічного інтерференційного мікроскопа з цифровою реєстрацією голограм. Розроблено методику дослідження оптичних волокон, подано експериментальні результати визначення розподілу показника заломлення у поперечному перерізі оптичного волокна. The purpose of this paper is investigation the possibilities of applying methods of digital holographic interferometry to study the internal structure of the optical fiber, including the distribution of the refractive index in the cross -section. Modern development of micro-and nanotechnology requires the development of new approaches and methods for the diagnosis properties of mediums and objects, and research processes and structural changes that are taking place under the influence of external factors. In particular, diagnosis and metrology are important in the field of fiber technique since it is known that increasing the density of information that is transmitted through the optical fiber requires their micro- and nanostructuring. Optical microscopy is the classical method studying of the micro- and nanoscale mediums, phenomena and processes. However, main disadvantages are limitation of the spatial resolution due to diffraction effects, and the inability (or technical complexity) 3D imaging of phase microscopic objects. The coherent-optical methods including methods of holographic interferometry received the high actuality with the appearance of the coherent radiation sources which are the most promising tools for experimental investigation of the materials characteristics and properties of the phase and diffuse macro- and micro objects. At the same time, application of the holographic interferometry to study microscopic objects is only possible at combining it with classical microscopy. This combination allows produce the qualitative and quantitative diagnosis with a high sensitivity and precision as well as achieving image magnification. Indicated disadvantages will be disappeared when holographic interferometry and classical microscopy will be combined. This combination allows produce the qualitative and quantitative diagnosis with a high sensitivity and precision as well as achieving image magnification. In this work method of digital holographic interferometry to research the phase microobject are presented. Model of holographic interference microscope with a digital recording of holograms and receiving interferogram by subtracting two video signals has been developed. Technique investigation the distribution of refractive index in optical fibers has been developed. Experimental results of the distribution of the refractive index in the optical fiber are presented. It is shown that the sensitivity of the developed digital interference microscope depends on the characteristics of CCD and microscope zoom.Item Метод диференційованого мультипотокового керування трафіком у транспортних програмно-керованих мережах(Видавництво Львівської політехніки, 2014) Климаш, М. М.; Шпур, О. М.; Багрій, В. О.; Швець, А. Л.Запропоновано спосіб динамічної адаптації пропускної здатності віртуальних каналів транспортної мережі операторів зв’язку. Розроблено метод диференційованого мультипотокового керування трафіком, який реалізує гнучкий механізм управління мережевими ресурсами. Для перерозподілу та балансування трафіку метод використовує алгоритм зваженого справедливого розподілу ресурсів фізичних каналів, що забезпечує ефективність використання їх пропускної здатності на рівні 90 %, уникаючи перевантаження. Для перевірки ефективності запропонованого методу розроблено імітаційну модель та проведено дослідження, в результаті яких підтверджено доцільність упровадження методу на транспортній мережі оператора зв’язку. In this paper is proposed a solution to the problem of low efficiency of bandwidth usage of physical channels. In the beginning adducted a necessity to implement proposed solutions at transport network. The main problem of transport networks is low level of utilization of optical channels resources. As a result it is often very expensive to exploit such a network due to high capital and operational costs. The method of distributed multi-flow traffic engineering in software-defined networks based on means and mechanisms of flow processing by Openflow switches has been developed. This method ensures optimal dynamic redistribution of physical channel bandwidth among several logical flows in the network, thus it achieves more than 90 % of bandwidth utilization. The method uses sophisticated methods and algorithms of traffic engineering. Method using Hurst index allows evaluation of future network state and redistribution of logical flows over a different physical channels while supporting utilization efficiency of these channels above 90 %. The method of load balancing uses as a basis priorities of physical branches of one logical channel. Thus this method allows the network to adapt to dynamically-changing incoming traffic, based on mechanism of prognostication the traffic rate using Hurts index. As a result algorithm of the method consists of two stages that ensure effective traffic redistribution: traffic prognostication and load balancing. Searching for optimal physical routes for one logical channel is based on Gallaher multi-path data transfer model. The method of calculating the efficiency of utilization of provided bandwidth for a particular physical channel as the basis for the mechanisms of redistribution of the total bandwidth between various logical channels is developed. Using mechanism of redistribution of flows into different physical channels controller can unload and set it to stand-by mode those segments of the network that are low-utilized. To verify the effectiveness of the proposed method of load balancing simulation model was created based on distributed system of servers and software models of SDN components developed using C++ language. The result of modeling confirmed the expediency of introduction the method on a real transport network.