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New Metric for World Wide Web Service Quality , Journal of Telecommunications and Information Technology, 2014, nr 2
Get PDFThe main topic of this paper is the quality of the WWW service evaluation. The authors present well-known measurement methods, and present the new “Power” metric for quality, advocating it as a method of assessing the quality of such service. This metric is based on the most important network parameters that affect any assessment of the WWW service, i.e. Web page opening time and download data transfer rate. The new method is easy to implement, fast in operation, and provides stable and repeatable result
System zdalnego monitorowania medycznego osób starszych i niepełnosprawnych – EDFAS. Telekomunikacja i Techniki Informacyjne, 2014, nr 3-4
Get PDFW artykule przedstawiono wyniki prac projektu EDFAS, realizowanego w ramach międzynarodowego programu EUREKA, obejmującego zdalne monitorowanie parametrów życiowych osób starszych i niepełnosprawnych za pomocą specjalizowanego systemu komputerowego
An Incentives Model Based on Reputation for P2P Systems, Journal of Telecommunications and Information Technology, 2013, nr 4
Get PDFIn this paper an incentive model to improve the collaboration in peer-to-peer networks is introduced. The proposed solution uses an incentives model associated with reputation issues as a way to improve the performance of a P2P system. The reputation of the all peers in the system is based on their donated resources and on their behavior. Supplying peers use these rules as a way to assign its outgoing bandwidth to the requesting peers during a content distribution. Each peer can build its best paths by using a best-neighbor policy within its neighborhood. A peer can use its best paths to obtain best services related to content search or download. The obtained results show that proposed scheme insulates the misbehaving peers and reduces the free-riding so that the systems performance is maximized
Predictive Modeling in a VoIP System, Journal of Telecommunications and Information Technology, 2013, nr 4
Get PDFAn important problem one needs to deal with in a Voice over IP system is server overload. One way for preventing such problems is to rely on prediction techniques for the incoming traffic, namely as to proactively scale the available resources. Anticipating the computational load induced on processors by incoming requests can be used to optimize load distribution and resource allocation. In this study, the authors look at how the user profiles, peak hours or call patterns are shaped for a real system and, in a second step, at constructing a model that is capable of predicting trends
Telemaco: A Language Oriented Tool for Graph-based Models Layout Optimization, Journal of Telecommunications and Information Technology, 2013, nr 4
Get PDFProgress of ICT is shifting the paradigm of systems organization towards a distributed approach, in which physical deployment of components influences the evaluation of systems properties. This contribution can be considered as a problem of graph layout optimization, well-known in literature where several approaches have been exploited in different application fields with different solving techniques. Then again, complex systems can be only studied by means of different formalisms which codification is the aim of language engineering. Telemaco is a tool that supports a novel approach for the application of graph layout optimizations to heterogeneous models, based on the OsMoSys framework and on the language engineering principles. It can cope with different graph-based formalisms by exploiting either their core graph nature or their different specialized features by means of language hierarchies. In this paper Telemaco is introduced together with its foundations and an example of application to Wireless Sensor Networks (WSN) deployment
Elastyczne sieci optyczne. Telekomunikacja i Techniki Informacyjne, 2013, nr 1-2
Get PDFArtykuł przybliża koncepcję elastycznej sieci optycznej i charakterystyczne zagadnienia związane z jej implementacją. Przedstawiono w nim standardy styków optycznych sieci Ethernet 40 Gbit/s i 100 Gbit/s zawarte w dokumencie IEEE 802.3ba. Następnie opisano szczelinowy charakter widma elastycznej sieci optycznej, porównując ze sztywnym podziałem częstotliwości DWDM. Nakreślono problem planowania i dynamicznej alokacji zasobów w sieci
The Development of Kalman Filter Learning Technique for Artificial Neural Networks, Journal of Telecommunications and Information Technology, 2013, nr 4
Get PDFThe paper presents an idea of using the Kalman Filtering (KF) for learning the Artificial Neural Networks (ANN). It is shown that KF can be fully competitive or more beneficial method with comparison standard Artificial Neural Networks learning techniques. The development of the method is presented respecting selective learning of chosen part of ANN. Another issue presented in this paper is the author’s concept of automatic selection of architecture of ANN learned by means of KF based on removing unnecessary connection inside the network. The effectiveness of presented ideas is illustrated on the examples of time series modeling and prediction. Considered data came from the experiments and situ measurements in the field of structural mechanics and materials
Statistical Analysis and Modeling of SIP Traffic for Parameter Estimation of Server Hysteretic Overload Control, Journal of Telecommunications and Information Technology, 2013, nr 4
Get PDFThe problem of overload control in Session Initiation Protocol (SIP) signaling networks gives rise to many questions which attract researchers from theoretical and practical point of view. Any mechanism that is claimed to settle this problem down demands estimation of local (control) parameters on which its performance is greatly dependent. In hysteretic mechanism these parameters are those which define hysteretic loops. In order to find appropriate values for parameters one needs adequate model of SIP traffic flow circulating in the network under consideration. In this paper the attempt is made to address this issue. Analysis of SIP traffic collected from telecommunication operator’s network is presented. Traffic profile is built. It is shown that fitting with Markov Modulated Poisson Process with more than 2 phases is accurate. Estimated values of its parameters are given
Call and Connections Times in ASON/GMPLS Architecture, Journal of Telecommunications and Information Technology, 2013, nr 3
Get PDFIt is assumed that demands of information society could be satisfied by architecture ASON/GMPLS comprehended as Automatically Switched Optical Network (ASON) with Generalized Multi-Protocol Label Switching (GMPLS) protocols. Introduction this solution must be preceded by performance evaluation to guarantee society expectations. Call and connections times are in ASON/GMPLS architecture important for real-time applications. Practical realization is expensive and simulations models are necessary to examine standardized propositions. This paper is devoted to the simulation results of ASON/GMPLS architecture control plane functions in OMNeT++ discrete event simulator. The authors make an effort to explore call/connection set-up times, connection release times in a single domain of ASON/GMPLS architecture
Dual-band Multi Slot Patch Antenna for Wireless Applications, Journal of Telecommunications and Information Technology, 2013, nr 2
Get PDFIn this paper a novel configuration of broadband multi slot antenna for C/X bands is presented and analyzed. By cutting two diamond slots in the middle of the rectangular patch and three triangular slots in the right side of the patch, resonances can be created. Microstrip feed line is used in the down side region of the patch. Antenna characteristics were simulated using a finite element method (HFSS). According to simulations, the proposed multiple slot antennas can provide two separated impedance bandwidths of 970 MHz (about 11.96% centred at 8.11 GHz band) and 890 MHz (about 9.76% centred at 9.42 GHz band) and stable radiation patterns, promising for satellite systems