Filtry
wszystkich: 339
wybranych: 272
Wyniki wyszukiwania dla: IP QOS, MPLS
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Zagadnienia inżynierii ruchu w sieciach NGN bazujących na IMS
PublikacjaSpełnienie wymagań dotyczących szybkości i dokładności dostarczania informacji powoduje konieczność wprowadzenia i poprawnego zaprojektowania sieci telekomunikacyjnych następnej generacji. W tym celu należy wskazać i zastosować odpowiednie modele ruchowe i metody inżynierii ruchu, czemu poświęcono niniejszą pracę. W pracy zaprezentowano standaryzację i architektury koncepcji IMS (IP Multimedia Subsystem) oraz bazujących na niej...
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Call Processing Performance in a Multidomain IMS/NGN with Asymmetric Traffic
PublikacjaIn this paper we continue our research using the previously proposed analytical traffic model of a multidomain Next Generation Network (NGN), which is standardized for delivering multimedia services based on the IP Multimedia Subsystem (IMS). The aim of the model is to assess mean Call Set-up Delay (CSD) and mean Call Disengagement Delay (CDD), which are standardized call processing performance parameters. The output variables...
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Reliable routing and resource allocation scheme for hybrid RF/FSO networks
PublikacjaSignificant success of wireless networks in the last decade has changed the paradigms of communication networks design. In particular, the growing interest in wireless mesh networks (WMNs) is observed. WMNs offer an attractive alternative to conventional cable infrastructures, especially in urban areas, where the cost of new installations is almost prohibitive. Unfortunately, the performance of WMNs is often limited by the cluttered...
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Quality Evaluation of Speech Transmission via Two-way BPL-PLC Voice Communication System in an Underground Mine
PublikacjaIn order to design a stable and reliable voice communication system, it is essential to know how many resources are necessary for conveying quality content. These parameters may include objective quality of service (QoS) metrics, such as: available bandwidth, bit error rate (BER), delay, latency as well as subjective quality of experience (QoE) related to user expectations. QoE is expressed as clarity of speech and the ability...
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Towards More Realistic Probabilistic Models for Data Structures: The External Path Length in Tries under the Markov Model
PublikacjaTries are among the most versatile and widely used data structures on words. They are pertinent to the (internal) structure of (stored) words and several splitting procedures used in diverse contexts ranging from document taxonomy to IP addresses lookup, from data compression (i.e., Lempel- Ziv'77 scheme) to dynamic hashing, from partial-match queries to speech recognition, from leader election algorithms to distributed hashing...
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Prototyp bezprzewodowego systemu informacyjnego do monitorowania i alarmowania o stanie statku.
PublikacjaW artykule przedstawiono opis projektu i realizacji praktycznej prototypu urządzenia informacyjnego do bezprzewodowej wymiany danych pomiędzy systemami pokładowymi statku a telefonem lub tabletem z zainstalowanym systemem Android. Przedstawione urządzenie ma charakter doradczy i służy jedynie do monitorowania i ewentualnego alarmowania użytkownika o przekroczonym poziomie dopuszczalnym wartości mierzonej. Opisano dostępne dotychczas na...
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Metaheuristic algorithms for optimization of resilient overlay computing systems
PublikacjaThe idea of distributed computing systems has been gaining much interest in recent years owing to the growing amount of data to be processed for both industrial and academic purposes. However, similar to other systems, also distributed computing systems are vulnerable to failures. Due to strict QoS requirements, survivability guarantees are necessary for provisioning of uninterrupted service. In this article, we focus on reliability...
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Quality Analysis of Audio-Video Transmission in an OFDM-Based Communication System
PublikacjaApplication of a reliable audio-video communication system, brings many advantages. With the spoken word we can exchange ideas, provide descriptive information, as well as aid to another person. With the availability of visual information one can monitor the surrounding, working environment, etc. As the amount of available bandwidth continues to shrink, researchers focus on novel types of transmission. Currently, orthogonal frequency...
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Analysis of IMS/NGN Call Processing Performance Using Phase-Type Distributions Based on Experimental Histograms
PublikacjaThe paper describes our further research done with the proposed analytical and simulation traffic models of the Next Generation Network (NGN), which is standardized for delivering multimedia services with strict quality and includes elements of the IP Multimedia Subsystem (IMS). The aim of our models of a single IMS/NGN domain is to evaluate two standardized call processing performance parameters, which appropriate values are very...
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Analysis of IMS/NGN call processing performance using phase-type distributions
PublikacjaThis work is a continuation of our research on the traffic model dedicated for design and analysis of the Next Generation Network (NGN), which is standardized for distribution of current and future multimedia services based on the IP Multimedia Subsystem (IMS). Our analytical and simulation models allow evaluation of mean Call Set-up Delay E(CSD) as well as mean Call Disengagement Delay E(CDD) in a single domain of IMS/NGN. Ensuring...
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Analiza i projektowanie wielościeżkowych protokołów wyboru tras dla niskoorbitowych szerokopasmowych systemów satelitarnych
PublikacjaW pracy przedstawiono charakterystykę i budowę niskoorbitowych sieci satelitarnych. Pokazano też szeroki wachlarz możliwych sposobów kierowania ruchem w takich sieciach. Przedstawiono metody optymalizujące przepustowość sieci oraz czasy opóźnień wprowadzanych przez sieć. Dla konkretnych sieci satelitarnych przeprowadzono analizę obciążeń łączy międzysatelitarnych i pokazano, że zastosowanie protokołów routingu wielościeżkowego...
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Dynamiczne sieci VLAN z zastosowaniem mechanizmów silnego uwierzytelniania użytkowników oraz metod ochrony przesyłanych informacji
PublikacjaW pracy zaprezentowano definicje wirtualnych sieci LAN. Klasyfikację algorytmów sieci VLAN przeprowadzono używając kryterium przynależności tzn. port przełącznika, adres MAC, adres sieciowy, adres grupowy IP lub reguły logiczne. Opisano zasady tworzenia sieci VLAN w środowisku wieloprzełącznikowym z użyciem rozwiązań standardu 802.1Q lub protokółu ISL. Scharakteryzowano rozwiązania LANE oraz MPOA umożliwiającego integrację z siecią...
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Thermodynamic and economic analysis of nuclear power unit operating in partial cogeneration mode to produce electricity and district heat
PublikacjaThis paper presents the methodology of techno-economic analysis for a nuclear unit operating in partial cogeneration mode and its application for the case study: a nuclear power plant planned in Poland. The research objectives were: to propose EPR, AP1000 and ESBWR nuclear condensing-extraction turbine systems modifications required for operation in cogeneration, to determine optimal heat production and heat transport line (HTL)...
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Web-based real-time simulation system
PublikacjaThe paper presents the development of a simulation system composed of a real-time plant simulator with real-time controller included in the software-in-the-loop structure using web-based communication. The client-server architecture build in a TCP/IP network environment was introduced, where the server is a computing unit for real-time high temporal resolution plant simulation (and optionally also as controllers' platform) and...
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Open-Source Coprocessor for Integer Multiple Precision Arithmetic
PublikacjaThis paper presents an open-source digital circuit of the coprocessor for an integer multiple-precision arithmetic (MPA). The purpose of this coprocessor is to support a central processing unit (CPU) by offloading computations requiring integer precision higher than 32/64 bits. The coprocessor is developed using the very high speed integrated circuit hardware description language (VHDL) as an intellectual property (IP) core. Therefore,...
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Subjective quality evaluation of 8- and 10-bit MP4-coded video sequences from Netflix
PublikacjaRecently, many researchers have been intensively conducting quality of service (QoS), quality of experience (QoE), and user experience (UX) studies in the field of video analysis. This paper is intended to make a new, complementary contribution to this field. Currently, streaming platforms are key products in relation to delivering video content online. Most often, they include the MP4 video format, which is most widely utilized...
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The influence of the UV irradiation on degradation of virgin rapeseed oils
PublikacjaThis paper presents research which is a continuation of the investigations described earlier. The aim of these studies was to determine the influence of UV irradiation on flavor and the oxidative stability of different rapeseed oils varieties. For the purpose of this study, oil samples underwent accelerated deterioration for 4.5 h under a UV light test. In the obtained sample, characteristic values (peroxide (PV, 1.23–1.62 meq...
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Aplikacje i usługi a technologie sieciowe
PublikacjaObserwując tempo rozwoju technologii sieciowych oraz usług i aplikacji stajemy przed ogromnym dylematem jak wykorzystać istniejące możliwości by modernizować wybrane usługi i aplikacje zgodnie z ciągle zmieniającymi się potrzebami użytkowników. Bardzo często sygnalizowane nowe technologie czy aplikacje mają jednak czysto charakter biznesowy podporządkowany prawom marketingu i nie wnoszą wielu istotnych zmian. Dlatego jest ważne...
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Implementation of failover and load balancing algorithms in SIP PBX High Availability system
PublikacjaGoal of the project was to design a High Availability SIP VoIP system that guarantees access to additional services like auto-attendent and automatic call distribution. The realization of the project required system to have load balancing and failover algorithms implemented. From the end users’ point of view the whole system had to figure as a single element. After taking under consideration the known methods of implementations...
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Outcomes of gynecologic cancer surgery during the COVID-19 pandemic: an international, multicenter, prospective CovidSurg-Gynecologic Oncology Cancer study
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Effect of COVID-19 pandemic lockdowns on planned cancer surgery for 15 tumour types in 61 countries: an international, prospective, cohort study
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Elective surgery system strengthening: development, measurement, and validation of the surgical preparedness index across 1632 hospitals in 119 countries
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