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PL
W artykule przedstawiono koncepcję adaptacyjnej metody zarządzania zasobami multipleksu w radiofonii cyfrowej DAB+. Dokonano analizy profilu programów radiowych na podstawie treści realizowanych audycji. Omówiono wyniki badań symulacyjnych dla czterech multipleksów o odmiennej konfiguracji i zawartości programów. Przedstawiono koncepcję demonstratora technologicznego, w pełni kompatybilnego ze standardem DAB+.
EN
In this paper we present the concept of an adaptive multiplex resource allocation method in the DAB+ broadcast system. We provide an analysis of profiles of a radio program with respect to transmitted content. We discuss simulation results of four multiplexes, with different configurations and programs. We describe the concept of a technological demonstrator, fully compatible with the DAB+ standard.
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.
EN
In this paper the quality aspects of bitrate and loudness in digital broadcasting and webcasting systems are examined. The authors discuss a survey concerning user preferences related with processing and managing audio content. The coding efficiency of a popular audio format is analyzed in the context of storing media. An objective study on a representative group of signal samples, as well as a subjective study of the perceived quality of real-time broadcasted and webcasted radio programs are performed.
PL
W artykule omówiono rolę komunikacji bezprzewodowej w życiu współczesnego człowieka. Dokonano analizy wybranych technologii w zakresie pełnionych funkcji. Przedstawiono wyniki badań przeprowadzonych na grupie 100 osób, uwzględniając aspekty społeczne, ekonomiczne oraz techniczne, w zestawieniu z globalnymi trendami na rynku usług oraz sprzętu mobilnego i bezprzewodowego.
EN
In this paper we discuss the role of wireless communications in the life of a modern man. We perform an analysis of selected technologies in terms of their impact on society. We present results of a research study performed on a group of 100 people, taking into account the social, economical and technical aspects, with respect to global trends on the market of services, as well as mobile and wireless devices.
EN
Broadcasting services seek to optimize their use of bandwidth in order to maximize user’s quality of experience. They aim to transmit high-quality digital speech and music signals at the lowest bitrate. They intend to offer the best quality under available conditions. Due to bandwidth limitations, audio quality is in conflict with the number of transmitted radio programs. This paper analyzes whether the quality of real-time digital DAB+ broadcasted radio programs surpasses the quality offered by analog FM radio. We also perform a subjective and objective quality assessment comparative study of the HE-AAC v2 audio codec used in DAB+. The subjective studies were carried out using the MOS test methodology, whereas the objective tests were realized using the ViSQOLAudio metric. These studies were followed by a questionnaire concerning the migration from analog to digital radio domain.
EN
In the age of digital media, delivering high quality content to consumers is one of the most demanding tasks. There exist numerous broadcasting standards, with different pros and cons, and the DAB/DAB+ (Digital Audio Broadcasting) system is one of the most popular among them. From an engineer’s perspective, efficient resource management under limited bandwidth conditions has always been a challenge. In this paper a subjective quality assessment study of the DAB and DAB+ broadcasting system is performer on a representative group of signal samples. It describes the radio link, including a fully functional transmitter designed for the purpose of this test, as well as the receiver side representing a commercially available consumer device, for a truly real-time and end-to-end quality evaluation.
PL
Referat zawiera opis uzyskanych rezultatów projektowych i konstrukcyjnych systemu lokalizacyjnego przeznaczonego do monitoringu i prezentacji położenia osób w obiektach (budynki, budowle), w których proces lokalizacji metodami radiowymi jest utrudniony. Przedstawione zostały elementy składowe systemu oraz uzyskane parametry użytkowe.
EN
This paper contains a brief description of an indoor positioning system designed to work in closed environments, where navigation based only on radio wave propagation may be inefficient. We present design and construction features, as well as system components and performance characteristics.
PL
W artykule opisano pomiary jakości transmisji rzeczywistych programów radiowych nadawanych w standardzie DAB+. Omówiono badania ankietowe dotyczące przełączenia emisji programów radiowych z techniki analogowej FM na cyfrową DAB+. Dokonano analizy typów audycji prowadzonych w godzinie największej słuchalności pod kątem efektywnego zarządzania ograniczonymi zasobami częstotliwościowymi. Zaproponowano metodę adaptacyjnego doboru przepływności przydzielanych poszczególnym programom radiowym.
EN
In this paper we examine the quality of real-time DAB+ broadcasted radio programs. We discuss a survey concerning the migration from analog FM to digital DAB+ radio domain. We analyze the type of content transmitted over different radio programs during primetime. We propose an adaptive bitrate assignment method for DAB+ broadcasted radio programs.
EN
In recent years, many alternative technologies of delivering audio content have emerged, with different advantages and disadvantages. In this paper pros and cons of digital audio broadcasting and webcasting transmission techniques in a network quality perspective are described. A case study of user expectations with respect to currently available services is analyzed, and the perceived quality of real digital broadcasted and webcasted radio stations is examined.
EN
Radio is by far the most accessible medium. With its mobility and availability, it attracts listeners by its simplicity and friendliness. The present information situation is characterized by the convergence of computers, mobile devices, telecommunication and broadcasting technologies and the divergence of different ways of delivering and storing media. Consumers are overwhelmed by new electronic gadgets appearing every year. They are astonished by new technical innovations that are being designed to ease their life and change their habits. Even the broadcasting sector itself is facing significant changes, especially a growing competition between the private and public sector. This article reviews the current status of analog and digital broadcasting technologies. It analyzes a case study of user expectations related with today’s digital media, particularly radio transmission. We discuss the principal possibilities, limitations and user expectations related with digital audio broadcasting, as well as the economic, technological, regulatory and frequency management factors.
PL
W artykule omówiono rolę mediów elektronicznych w życiu współczesnego człowieka. Dokonano analizy wybranych mediów w zakresie pełnionych funkcji. Przedstawiono wyniki badań przeprowadzonych na grupie 45 osób, uwzględniając aspekty społeczne, ekonomiczne oraz techniczne.
EN
In this paper we discuss the role of electronic media in the life of a modern man. We perform an analyzis of selected media in terms of their impact on society. We present results of a research study performed on a group of 45 people, taking into account the social, economical and technical aspects.
PL
Dokonano przeglądu wybranych usług lokalizacyjnych przeznaczonych dla służb ratowniczych. Opisano metody pozycjonowania łączące technikę radiową oraz inercyjną a także mechanizmy przetwarzania informacji wykorzystywane w środowisku wewnątrzbudynkowym.
EN
In this paper we present a survey on selected LBS services dedicated to emergency services. We describe positioning methods including radio and inertial techniques, as well as Information processing mechanisms applied in indoor environments.
13
Content available Quality Expectations of Mobile Subscribers
EN
Mobile systems, by nature, have finite resources. Radio spectrum is limited, expensive and shared between many users and services. Mobile broadband networks must support multiple applications of voice, video and data on a single IP-based infrastructure. These converged services each have unique traffic holding and quality requirements. A positive user experience must be obtained through efficient partitioning of the available wireless network resources. The 3rd Generation Partnership Project (3GPP) has developed a comprehensive Quality of Service (QoS) parameter to address this problem. The regular control of service quality is critical for operators to ensure user Quality of Experience (QoE), establish new business models and monetize services. It enables operators to employ fair-use resource policies and maintain network performance during peak traffic times. Wireless mobile communication is tending towards an integrated system of Internet and telecommunication technologies, where mobile users move freely anytime and everywhere. They desire to communicate with any device using the best service available. In this paper QoS management issues in mobile communication are described. The authors present an insight into subscriber behavior and related factors that affect the QoE of mobile data services.
14
Content available Survey of Radio Navigation Systems
EN
At present, there is a growing demand for radio navigation systems, ranging from pedestrian navigation to consumer behavior analysis. These systems have been successfully used in many applications and have become very popular in recent years. In this paper we present a review of selected wireless positioning solutions operating in both indoor and outdoor environments. We describe different positioning techniques, methods, systems, as well as information processing mechanisms.
PL
Przedstawiono technologię radia programowalnego jako nowoczesną platformę dydaktyczną. Zaproponowane podejście umożliwia efektywniejsze planowanie stanowisk laboratoryjnych, skrócenie czasu realizacji etapów związanych z projektowaniem, symulacją i testowaniem działania łącza radiowego, a także elastyczną zmianę stanowisk laboratoryjnych zgodnie z dynamicznym rozwojem współczesnych systemów radiokomunikacyjnych.
EN
In this paper we present a SDR platform as a new approach for teaching communications. This approach makes planning and performing laboratories more efficient. It can shorten the execution time steps involved in design, simulation and testing radio links. It also enables to flexibly in change laboratory stands in accordance with the dynamic development of modem radio systems.
PL
Przedstawiono przegląd wybranych komercyjnych systemów radiolokalizacyjnych pracujących w środowisku wewnątrzbudynkowym oraz zewnątrzbudynkowym. Opisano podstawy i zasady działania usług lokalizacyjnych oraz mechanizmy przetwarzania informacji w systemach GIS.
EN
In this paper we present a currently available radio location systems operating in both indoor and outdoor environments. We explain the fundamentals and operating principles of location-based services as well as information processing mechanisms in GIS systems.
EN
The paper deals with determining theoretical minimum of conductive heat losses possible in the Warsaw district heating network as a result of modernization of pipelines. In the first part of the article, two calculation methods of the current heat losses are presented. In the second part, the losses are calculated for different modernization scenarios. The results presented are a part of the graduate work at the Warsaw University of Technology. The work has been funded by Dalkia Warszawa and technically supported by Heat-Tech Centre, R&D Centre of Dalkia Group located in Warsaw.
PL
Artykuł jest poświęcony określeniu teoretycznych minimalnych strat ciepła przez przewodzenie jakie mogą zostać osiągnięte w warszawskiej sieci ciepłowniczej w wyniku modernizacji rurociągów. W pierwszej części artykułu przedstawiono dwie metody obliczania istniejących straty ciepła. W drugiej części obliczone są straty ciepła przy różnych scenariuszach modernizacji rurociągów. Zaprezentowane rezultaty obliczeń są częścią pracy dyplomowej obronionej na Politechnice Warszawskiej. Praca była finansowana przez Dalkia Warszawa przy wsparciu technicznym Heat-Tech Center, Ośrodek R&D grupy Dalkia, zlokalizowany w Warszawie.
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