15,082 research outputs found
A survey of digital television broadcast transmission techniques
This paper is a survey of the transmission techniques used in digital television (TV) standards worldwide. With the increase in the demand for High-Definition (HD) TV, video-on-demand and mobile TV services, there was a real need for more bandwidth-efficient, flawless and crisp video quality, which motivated the migration from analogue to digital broadcasting. In this paper we present a brief history of the development of TV and then we survey the transmission technology used in different digital terrestrial, satellite, cable and mobile TV standards in different parts of the world. First, we present the Digital Video Broadcasting standards developed in Europe for terrestrial (DVB-T/T2), for satellite (DVB-S/S2), for cable (DVB-C) and for hand-held transmission (DVB-H). We then describe the Advanced Television System Committee standards developed in the USA both for terrestrial (ATSC) and for hand-held transmission (ATSC-M/H). We continue by describing the Integrated Services Digital Broadcasting standards developed in Japan for Terrestrial (ISDB-T) and Satellite (ISDB-S) transmission and then present the International System for Digital Television (ISDTV), which was developed in Brazil by adopteding the ISDB-T physical layer architecture. Following the ISDTV, we describe the Digital Terrestrial television Multimedia Broadcast (DTMB) standard developed in China. Finally, as a design example, we highlight the physical layer implementation of the DVB-T2 standar
Interactive television or enhanced televisiion? : the Dutch users interest in applications of ITV via set-top boxes
This paper is both an analysis of the phenomenon of interactive television with background concepts of interactivity and television and a report of an empirical investigation among Dutch users of set-top-box ITV. In the analytic part a distinction is made between levels of interactivity in the applications of ITV. Activities labelled as selection, customisation, transaction and reaction reveal low levels of interactivity. They may be called ‘enhanced television’. They are extensions of existing television programmes that keep their linear character. Activities called production and conversation have the potential of higher interactivity. They may lead to ‘real’ interactive television as the user input makes a difference to programmes. It is suggested that so-called hybrid ITV– TV combined with telephone and email reply channels- and (broadband) Internet ITV offer better opportunities for high interactivity than set-top-box ITV. \ud
The empirical investigation shows that the demand of subscribers to set-top-box ITV in the Netherlands matches supply. They favour the less interactive applications of selection and reaction. Other striking results are that young subscribers appreciate interactive applications more than the older ones and that those with a low level of education prefer these applications more than high educated subscribers. No significant gender differences were found
Evidence-informed regulatory practice: an adaptive response, 2005‑15
Overview: In this occasional paper, the ACMA reflects on its regulatory practice over the past 10 years; specifically, the role of research in evidence-informed decision-making and regulation. It looks at how the ACMA has used research in an environment of ongoing change to document and build evidence, inform public debate about regulation, and build capability among our stakeholders to make communications and media work in Australia’s national interest
On Content-centric Wireless Delivery Networks
The flux of social media and the convenience of mobile connectivity has
created a mobile data phenomenon that is expected to overwhelm the mobile
cellular networks in the foreseeable future. Despite the advent of 4G/LTE, the
growth rate of wireless data has far exceeded the capacity increase of the
mobile networks. A fundamentally new design paradigm is required to tackle the
ever-growing wireless data challenge.
In this article, we investigate the problem of massive content delivery over
wireless networks and present a systematic view on content-centric network
design and its underlying challenges. Towards this end, we first review some of
the recent advancements in Information Centric Networking (ICN) which provides
the basis on how media contents can be labeled, distributed, and placed across
the networks. We then formulate the content delivery task into a content rate
maximization problem over a share wireless channel, which, contrasting the
conventional wisdom that attempts to increase the bit-rate of a unicast system,
maximizes the content delivery capability with a fixed amount of wireless
resources. This conceptually simple change enables us to exploit the "content
diversity" and the "network diversity" by leveraging the abundant computation
sources (through application-layer encoding, pushing and caching, etc.) within
the existing wireless networks. A network architecture that enables wireless
network crowdsourcing for content delivery is then described, followed by an
exemplary campus wireless network that encompasses the above concepts.Comment: 20 pages, 7 figures,accepted by IEEE Wireless
Communications,Sept.201
Optical network technologies for future digital cinema
Digital technology has transformed the information flow and support infrastructure for numerous application domains, such as cellular communications. Cinematography, traditionally, a film based medium, has embraced digital technology leading to innovative transformations in its work flow. Digital cinema supports transmission of high resolution content enabled by the latest advancements in optical communications and video compression. In this paper we provide a survey of the optical network technologies for supporting this bandwidth intensive traffic class. We also highlight the significance and benefits of the state of the art in optical technologies that support the digital cinema work flow
Molto+Media: Digital Culture Funding
This report profiles nine organizations identified by grantmakers and independent research as adventurous in their use of digital media. They represent a mix of arts disciplines, geographies, organizational sizes and media purposes. Some are using digital tools to extend organizational capacities in new ways while others are creating, documenting and disseminating the art itself.Conversations with these nine organizations revealed common themes:Organizations describe the work as building capabilities, not "doingprojects." Digital tools and platforms are now essential building blocksin an organization's work and need to be created accordingly.Leading digital culture entrepreneurs want grantmakers to makebigger bets on organizations with strong track records. Building newcapabilities is expensive, particularly at the scale of large culturalinstitutions.There is a sense that, globally, U.S. organizations lag. The E.U. hassupported open culture, digital initiatives aggressively, making Europe,in particular, a hotbed of digital cultureOrganizations are looking for much greater risk-taking from thefunding community. "Grantmakers still expect only home runs," saidmore than one organization, and they point out that in for-profitindustry many tech projects failDigital culture projects are helping organizations reach massaudiences as well as niches. Both are important.Several of the organizations in our profiles had received no dedicatedfunding for their work. "Our funders are not ready to do this, so wehave to do it ourselves," said interviewees.The most important theme of this report, though, is the incredible creativity and energy of these digital culture entrepreneurs. Cultural organizations and artists are using digital media to invent new ways to create and distribute art and to reach and engage audiences
High definition systems in Japan
The successful implementation of a strategy to produce high-definition systems within the Japanese economy will favorably affect the fundamental competitiveness of Japan relative to the rest of the world. The development of an infrastructure necessary to support high-definition products and systems in that country involves major commitments of engineering resources, plants and equipment, educational programs and funding. The results of these efforts appear to affect virtually every aspect of the Japanese industrial complex. The results of assessments of the current progress of Japan toward the development of high-definition products and systems are presented. The assessments are based on the findings of a panel of U.S. experts made up of individuals from U.S. academia and industry, and derived from a study of the Japanese literature combined with visits to the primary relevant industrial laboratories and development agencies in Japan. Specific coverage includes an evaluation of progress in R&D for high-definition television (HDTV) displays that are evolving in Japan; high-definition standards and equipment development; Japanese intentions for the use of HDTV; economic evaluation of Japan's public policy initiatives in support of high-definition systems; management analysis of Japan's strategy of leverage with respect to high-definition products and systems
Compendium of Applications Technology Satellite user experiments
The achievements of the user experiments performed with ATS satellites from 1967 to 1973 are summarized. Included are fixed and mobile point to point communications experiments involving voice, teletype and facsimile transmissions. Particular emphasis is given to the Alaska and Hawaii satellite communications experiments. The use of the ATS satellites for ranging and position fixing of ships and aircraft is also covered. The structure and operating characteristics of the various ATS satellite are briefly described
CellTV - on the Benefit of TV Distribution over Cellular Networks A Case Study
As mobile IP-access is becoming the dominant technology for providing
wireless services, the demand for more spectrum for this type of access is
increasing rapidly. Since IP-access can be used for all types of services,
instead of a plethora of dedicated, single-service systems, there is a
significant potential to make spectrum use more efficient. In this paper, the
feasibility and potential benefit of replacing the current terrestrial UHF TV
broadcasting system with a mobile, cellular data (IP-) network is analyzed. In
the cellular network, TV content would be provided as {one} of the services,
here referred to as CellTV. In the investigation we consider typical Swedish
rural and urban environments. We use different models for TV viewing patterns
and cellular technologies as expected in the year 2020. Results of the
quantitative analysis indicate that CellTV distribution can be beneficial if
the TV consumption trend goes towards more specialized programming, more local
contents, and more on-demand requests. Mobile cellular systems, with their
flexible unicast capabilities, will be an ideal platform to provide these
services. However, the results also demonstrate that CellTV is not a
spectrum-efficient replacement for terrestrial TV broadcasting with current
viewing patterns (i.e. a moderate number of channels with each a high numbers
of viewers). In this case, it is doubtful whether the expected spectrum savings
can motivate the necessary investments in upgrading cellular sites and
developing advanced TV receiver required for the success of CellTV
distribution.Comment: To appear on Trans. Broadcasting 201
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