Institute of Electron Technology
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2189 research outputs found
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100/1000 Gbit/s Ethernet and beyond, Journal of Telecommunications and Information Technology, 2009, nr 1
Get PDF100 Gbit/s Ethernet is foreseen in metro and access by 2014, while 1 Tbit/s Ethernet is forecasted for trunklinks before 1020. This paper reviews the advantages and constraints of the optical networking and discusses how they meet the 100 Gbit/s Ethernet needs
Karnoprawna ochrona usług świadczonych drogą elektroniczną na zasadzie dostępu warunkowego. Telekomunikacja i Techniki Informacyjne, 2009, nr 1-2
Get PDFPrzedstawiono karnoprawne oraz karnoadministracyjne aspekty odpowiedzialności z tytułu naruszenia uprawnień przedsiębiorców świadczących drogą elektroniczną usługi oparte lub polegające na dostępie warunkowym, w świetle obowiązującego prawodawstwa krajowego oraz unijnego. Wyjaśniono w szczególności pojęcie usług chronionych oraz zakres odpowiedzialności z tytułu świadczenia usług niedozwolonych oraz posiadania, używania, wytwarzania i wprowadzania do obrotu tzw. urządzeń niedozwolonych, tj. sprzętu lub oprogramowania zaprojektowanego lub przystosowanego do korzystania z usług chronionych bez uprzedniego upoważnienia usługodawcy
Modulo N Backoff Scheme for Effective QoS Differentiation and Increased Bandwidth Utilization in IEEE 802.11 Networks, Journal of Telecommunications and Information Technology, 2009, nr 2
Get PDFThe paper presents a new modulo N channel access scheme for wireless local area networks (WLANs). The novel solution derives from the distributed coordination function (DCF) of the IEEE 802.11 standard, further elaborated as enhanced distribution channel access (EDCA) by the 802.11e draft specification. The main innovation concerns improvement of the binary exponential backoff scheme used for collision avoidance in 802.11 networks. The most appealing feature of the new modulo N backoff scheme is that it outperforms the original 802.11 solution in terms of channel utilization ratio under any traffic conditions. Furthermore, the modulo N proposal can be naturally augmented with QoS differentiation mechanisms like 802.11e extensions. The prioritized modulo N scheme achieves better throughput-delay characteristics for multimedia traffic when compared with the original 802.11e proposal. At the same time, the new solution retains backward compatibility and includes all features which have made IEEE 802.11 networks extremely popular nowadays
Hierarchical Multiobjective Routing in MPLS Networks with Two Service Classes – A Meta-Heuristic Solution, Journal of Telecommunications and Information Technology, 2009, nr 3
Get PDFThe paper begins by reviewing a two-level hierarchical multicriteria routing model for MPLS networks with two service classes (QoS and BE services) and alternative routing, as well as the foundations of a heuristic resolution approach, previously proposed by the authors. Afterwards a new approach, of meta-heuristic nature, based on the introduction of simulated annealing and tabu search techniques, in the structure of the dedicated heuristic, is described. The application of the developed procedures to a benchmarking case study will show that, in certain initial conditions, this approach provides improvements in the final results especially in more “difficult” situations detected through sensitivity analysis
Simple Dynamic Threshold Decryption Based on CRT and RSA, Journal of Telecommunications and Information Technology, 2009, nr 2
Get PDFIn the paper we present a simple threshold decryption system based on the RSA cryptosystem. Our model avoids the application of the Shamir secret sharing protocol and is based only on the Chinese reminder theorem. The flexibility in the threshold level is attained due to the suitable preparation of the input data. The second part of the article describes a modification of the basic model, which admits the sender’s impact on the choice of the real receiver’s group
Laser Beam Attenuation Determined by the Method of Available Optical Power in Turbulent Atmosphere, Journal of Telecommunications and Information Technology, 2009, nr 2
Get PDFThis work is focused on the atmospheric turbulence effect and a new method for determining optical signal attenuation caused by turbulence is presented here. A new method of power budget of optical links comes from optical intensity distribution in a laser beam after the beam passed through turbulent atmosphere. Results given by this method are compared with Rytov approximation which is nowadays the most frequently used method for determining turbulent attenuation. Results for communication wavelength of 850 nm and 1550 nm are presented as well as the results for a wavelength of 633 nm
Model for Balancing Aggregated Communication Bandwidth Resources, Journal of Telecommunications and Information Technology, 2009, nr 3
Get PDFIn this paper we present a multicommodity bandwidth exchange model for balancing aggregated communication bandwidth resources (BACBR) that allows us to aggregate similar offers. In this model offers submitted to sell (or buy) the same, similar, or equivalent network resources (or demands for end-to-end connections) are aggregated into single commodities. BACBR model is based on the balancing communication bandwidth trade (BCBT) model. It requires much less variables and constraints then original BCBT, however the outcomes need to be disaggregated. The general model for disaggregation is also given in the paper
