Browsing by Author "Красько, О. В."

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Аналіз параметрів оптичного сигналу в повністю оптичній мережі з комутацією за довжинами хвиль
(Видавництво Львівської політехніки, 2014) Красько, О. В.; Демидов, І. В.; Брич, М. В.
Наведено результати розрахунків OSNR, основані на отриманій аналітичній моделі для частини повністю оптичної мережі, а також надано рекомендації для розробників оптичних мереж. This paper is devoted to the analysis of optical signal to noise ratio (OSNR) for all optical networks (AON) with wavelength switching at the cascade switching of optical amplifiers and optical cross connectors, including modelling of transient interferences in optical cross connectors, due to the impact of which there is an additional communication lines’ power penalty appears. In order to create economically profitable all optical net or to increase the throughput capacity of existent one considering its high performance, it is necessary to review such architectural and wavelength routing factors as network’s physical layers restrictions. Available publications omitted any effective solutions of the wavelength routing task on the criterion of the structural cost and BER minimization in the respective optical wavelength path. Despite it, while designing (logically or physically) an optical network with wavelength switching in the most optimal way, we need to be sure that physical technology of the network will grant us with the acceptable level of negative impact from network elements’ physical parameters. That’s why the investigation of the AON physical layer impact by means of OSNR analysis in the optical channels with wavelength switching at the real transmission parameters is the scope of this work. It is shown, that optical signal probably should pass the set of optical cross connectors (OXC), distributed optical amplifiers and interconnected optical fibers that definitely will worsen the quality of the signal. This is due to the decrease in signal power within optical fiber attenuation, crosstalks in OXC and summing the useful signal with noise of Amplified Spontaneous Emission (ASE) in optical amplifiers. This article contains the result of OSNR calculation after the AON section analytical simulation and recommendations for network designers were presented. Resulted analytical expressions allow making justified choice of the AON with wavelength switching structure based on a given set of input parameters and optimize this structure on the criterion of maximum OSNR values on the corresponding wave transmission paths. It is also shown that FEC technology according to G.709/Y.1331 is applicable when we need to make our AON structure more scalable in the spatial dimension and more powerful when more sophisticated switching core needed to be realized. We could also conclude that worsening of OSNR value is under strong impact of the number of optical amplifiers used, and in the less scale under impact of the OXC number..
Методика побудови мережі наземного телевізійного мовлення
(Видавництво Львівської політехніки, 2010) Колодій, Р. С.; Поліщук, А. В.; Красько, О. В.
Досліджено мережі наземного телевізійного мовлення і розроблено методику проектування зон впевненого прийому наземного телевізійного мовлення з врахуванням рельєфу місцевості і умов проходження радіохвиль у вільному просторі. The article devoted to research networks terrestrial television broadcasting design and development methods zones confirm receiving terrestrial television broadcasting with regard to terrain and conditions of radio waves in free space.
Оцінка параметрів мережі на етапі проектування оптичної транспортної системи
(Видавництво Львівської політехніки, 2013) Красько, О. В.
Since the primary network is nothing more than a set of channels, behavior and standards do not go beyond the network layer protocols, which includes a description of channels and methods of switching. Emerging of new solutions for access network FFTx and wideband mobile access network brings on a rapid growing of packet traffic, transmitted over transport network. For successful interaction between different access networks, the channels of the backbone network should be standardize according to the PDH and SDH hierarchy. Initially, the development of transport networks assumed that there are only primary channels data. The backbone network considered as a set of channels. Further separation of network traffic segments and segments greatly enhanced the access network scalability. Solutions for transport networks and access networks have become less formal and less standardized, compared with the solutions for the primary and secondary networks. The main problem that arises when transmitting packet traffic over SDH network is inconsistency throughputs of Gigabit Ethernet networks with a capacity of payload that can be transport by STM. This mismatch significantly reduce the efficiency of channel resources while packet traffic transmitted. One of the possible mechanisms of solving this problem is to use virtual concatenation (VCAT) in conjunction with general framing procedure (GFP) and link capacity adjustment scheme (LCAS). The concatenation principle leads in combining of multiple virtual containers. As result, their combined capacity used as a block for transmission of data, which size exceeds the size of single container. There are two types of concatenation – contiguous and virtual. Concatenation of both types forms a path of bandwidth is n times greater than the rate of a single container CVC, but with different principle of transmission between two nodes. The set of containers that deliver IP-traffic between two nodes A and B called contiguous concatenation (CCG) or virtual concatenation (VCG) group. The disadvantage of contiguous concatenation is that permissible speed transmission is strictly defined standard SDH hierarchy. The virtual concatenation utilizing channel resources more flexible by non-hierarchical speeds. The paper presents a hybrid mechanism for virtual concatenation (H-VCAT), which allows increasing channel utilizing by 10% compared with virtual concatenation and by 50–70% in comparison with contiguous concatenation. The evaluation of network parameters at the stage of optical transport system designing provided. The optimum set of containers for transferring traffic from FTTx access networks with 99.7% channel utilizing was proposed. Запропоновано механізм гібридної віртуальної конкатенації, який дозволяє підвищити ефективність використання каналу на 10% порівняно зі звичайною віртуальною конкатенацією та на 50–70% порівняно із суміжною конкатенацією. Оцінено параметри мережі на етапі проектування транспортної системи. Визначено оптимальні набори конкатенованих контейнерів для передавання трафіку від мереж доступу FTTx з швидкостями 1 Гбіт/с та 10 Гбіт/с.
Розрахунок параметрів якості транспортних мереж
(Видавництво Львівської політехніки, 2011) Красько, О. В.; Корецький, О. В.
Роботу присвячено аналізу методів розрахунку параметрів якості оптичних мереж та дослідженню проблем, що виникають під час переходу до фотонних мереж. The work devoted to research of methods for calculating the quality parameters of optical networks and research issues that arise during the transition to photonic networks.