Wyniki wyszukiwania - Biblioteka Nauki

1

Design and Analysis of EDF Scheduling Algorithm for a Chosen Network Traffic Problem: Implementation and Simulation Analysis

100%

Ighodaro J.

Journal of Applied Computer Science Methods

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2015

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tom Vol. 7 No. 1

43--52

EN

Workstations, CPU etc are in a period of transition, moving from a relatively slow network links and data oriented services to a high set fibre optic services and more diverse services. As such many of the hard and soft real time will not only demand high bandwidth but also a predictable and guarantee Quality of Service (QoS) along side ,which is not offered in a best effort network (BE). The provision and terms of (QoS) to real-time applications is a key issue in promising broadband packet switched networks and network of other sorts. Applications such as voice and video typically require QoS guarantees in terms of end-to-end data transfer delays. Supporting the diverse and of course, heterogeneous delay requirements of applications with widely varying characteristics requires packet scheduling schemes more sophisticated than First-In-First-Out (FIFO) at each switch in the network(2) are one of most accepted examples of such scheduling schemes. This points to the convincing need for a QoS, which apportion a high network utilization to be realized.In this paper, we focus on the EDF scheduling scheme, since it is known to provide the optimal delay performance (2), in the deterministic environment, and can for this reason be expected to perform well in the real time setting as well. The large amount of bandwidth as promised by the future network also offer the integration of real time applications, hard or soft.

2

Transmission Quality Measurements in DAB+ Broadcast System

88%

Gilski P. , Stefański J.

Metrology and Measurement Systems

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2017

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tom Vol. 24, nr 4

675--683

EN

In the age of digital media, delivering broadcast content to customers at an acceptable level of quality is one of the most challenging tasks. The most important factor is the efficient use of available resources, including bandwidth. An appropriate way of managing the digital multiplex is essential for both the economic and technical issues. In this paper we describe transmission quality measurements in the DAB+ broadcast system. We provide a methodology for analysing parameters and factors related with the efficiency and reliability of a digital radio link. We describe a laboratory stand that can be used for transmission quality assessment on a regional and national level.

3

Обзор протокола управления доступом buffer-to-buffer credits

88%

Беленькая М. , Креймер А. , Прохоров Д.

Zeszyty Naukowe WSEI. Seria Transport i Informatyka

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2017

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tom T. 7, nr 1

27--36

RU

В статье описано значение протоколa управления доступом, используемого в разных операционных системах, мультимедийных системах и сетях хранения данных. Также представлен протокол Buffer-to-Buffer и его функции.

EN

The article describes the importance of the admission control protocols used in various forms of operating systems, multimedia systems, and storage area networks. Discusses the Buffer-to-Buffer Credits protocol and its features.

4

Study on transmission quality in cellular 4G and 5G networks between 2019–2021: Impact of the COVID-19 pandemic on the level of provided services by operating base transceiver stations

75%

Falkowski-Gilski P. , Uhl T.

Zeszyty Naukowe Akademii Morskiej w Szczecinie

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2023

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tom nr 73 (145)

54--63

EN

The COVID-19 pandemic has significantly limited user mobility, not least among students. Remote learning had a particular impact on resource allocation in relation to using terrestrial cellular networks, especially 4G systems in urban agglomerations. This paper presents the results of a quality evaluation of an outdoor environment, carried out between 2019 and 2021 on the campus of a technical university. Annual studies are conducted using our own custom-built mobile application, installed on 50 mobile devices (i.e., smartphones) running Android OS. This study aims to determine the impact of reduced user mobility on access parameters in mobile networks, that is, both download and upload throughput as well as delay (ping), with a particular focus on serving base transceiver stations (BTSs). This research scenario involves long-term evolution (LTE) compatible user equipment (UE) that operates under four Polish mobile network operators (MNO), which includes roaming connections and the newly launched 5G standard.

5

Analiza jakości transmisji treści audio-wideo w symulowanym łączu telekomunikacyjnym z wykorzystaniem techniki OFDM

63%

Zamłyńska M. , Falkowski-Gilski P.

Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

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2022

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tom nr 4

219--223

PL

Wdrożenie niezawodnego systemu komunikacji audio-wideo przynosi wiele korzyści. Z uwagi na fakt, że ilość dostępnego pasma stale się kurczy, badacze koncentrują się na nowatorskich metodach transmisji. Obecnie technika OFDM (Orthogonal Frequency Division Multiplexing) jest szeroko stosowana zarówno w mediach przewodowych, jak i bezprzewodowych. W pracy przedstawiono badania jakości QoS (Quality of Service) symulowanego łącza transmisji danych, przy zmiennych poziomach SNR (Signal-to-Noise Ratio) oraz BER (Bit Error Rate).

EN

Application of a reliable audio-video communication system brings many advantages. As the amount of available bandwidth continues to shrink, researchers focus on novel types of transmission. Nowadays, OFDM (Orthogonal Frequency Division Multiplexing) is widely utilized both in wired and wireless media. In this paper we investigate the QoS (Quality of Service) parameters of a simulated data transmission system, including SNR (Signal-to-Noise Ratio) and BER (Bit Error Rate).

6

User experience evaluation study on the quality of 1K, 2K, and 4K H.265/HEVC video content

63%

Falkowski-Gilski P. , Uhl T. , Hoppe C.

Zeszyty Naukowe Politechniki Morskiej w Szczecinie

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2024

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tom nr 77 (149)

38--46

EN

Nowadays, most content creators focus on distributing rich media at the highest possible resolution. Currently, the majority of sold consoles, media players, computer hardware, as well as displays and TVs are advertised as 4K-compatible. The same trend is observed in the case of popular online streaming services and terrestrial TV broadcasts. Generally speaking, it is assumed that higher bitrates provide higher subjective judgements. In this paper, we present the results of a user experience (UX) evaluation study on the quality of video content coded and transmitted in different resolutions in the internet protocol (IP) environment. The image resolutions include 1K (1920×1080 pixels; full-HD), 2K (2560×1440 pixels; wide-QHD), and 4K (3840×2160 pixels; ultra-HD) content that are processed in the H.265/HEVC (high-efficiency video coding) format. A subjective evaluation is carried out in a laboratory consisting of 20 iMacs with a 21.5-inch 4K Retina (4096×2304 pixels) display. The group of viewers included 28 individuals aged between 21‒35 years old, comprising people with and without visual impairments. The obtained UX results are compared with previous experiments, including both objective quality of service (QoS) and subjective quality of experience (QoE), as well as the impact of downscaling to 1K from 2K and 4K. The outcomes of this study may be of particular interest to any party interested in video content processing and distribution, as well as consumption and storage.

7

Badanie jakości transmisji w sieciach komórkowych na przestrzeni lat 2019-2021: wpływ pandemii COVID-19 napoziom świadczonych usług

51%

Falkowski-Gilski P. , Uhl T.

Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

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2022

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tom nr 4

206--209

PL

Pandemia COVID-19 znacząco ograniczyła mobilność użytkowników, a w szczególności studentów. Nauka zdalna miała szczególny wpływ na sposób przydziału zasobów w sieciach komórkowych. Niniejsza praca przedstawia wyniki badań dotyczących jakości transmisji w środowisku zewnątrzbudynkowym. Kampanię pomiarową w latach 2019-2021 przeprowadzono na terenie kampusu uczelni technicznej. Każdego roku badania wykonano przy użyciu własnej autorskiej aplikacji mobilnej, zainstalowanej na 50 smartfonach działających pod kontrolą systemu Android.

EN

The COVID-19 pandemic has significantly limited user mobility, mainly students. Remote learning had a particular impact on resource allocation in case of cellular networks. This paper presents results of a quality evaluation in an outdoor environment. The measurement campaign between 2019-2021 was carried out at the campus of a technical university. Each year studies were performed using our own custom-build mobile application, installed on 50 smartphones running Android OS.

8

Badanie jakości sieci komórkowych w przededniu technologii 5G na wybranym przykładzie

51%

Falkowski-Gilski P. , Uhl T.

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tom nr 7-8

338--341, CD

PL

Wraz z rosnącą popularnością i dostępnością urządzeń mobilnych, zwiększa się liczba abonentów w sieci. Fakt ten prowadzi do wzrostu świadomości użytkowników, pod kątem jakości treści, które konsumują. Wielu dostawców usług oraz operatorów skupia swoje działania na monitorowaniu parametrów jakościowych QoN (Quality of Network) i QoS (Quality of Service). Niniejsza praca przedstawia wyniki badań przeprowadzonych na terenie kampusu uniwersyteckiego, uwzględniając ogólną wydajność sieci komórkowych w przededniu technologii 5G.

EN

With the raising popularity and availability of mobile devices, the number of network users continues to grow. This fact has raised user awareness, considering the quality of content they consume. Many service providers and operators focus on monitoring QoN (Quality of Network) and QoS (Quality of Service) parameters. This paper presents a study, carried out on a university campus, considering the overall performance of cellular networks on the eve of 5G.

9

Rola techniki MPLS w podnoszeniu jakości usług telekomunikacyjnych [QoS] w korporacyjnych sieciach IP

44%

Chmielewski J. M.

ABC Jakości

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2011

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nr 3-4