EBU Technical Review : No. 281 (Autumn 1999)
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Complete issue in PDF format |
(1719 KB) |
| Editorial | |
| Scanning
by numbers? |
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| News Acquisition | |
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Newsgathering and future technology |
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The Head of BBC Newsgathering considers the lessons of Kosovo and looks at future technical requirements for newsgathering, issuing a challenge for equipment manufacturers and developers. |
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| Mobile Multimedia | |
| Multimedia on the move overview of relevant
ACTS projects |
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The demand for information and entertainment on the move has grown spectacularly in recent years. The ubiquitous mobile phone meets some of these needs, but in a very limited way. Mobile multimedia services would meet our needs much more effectively. Multimedia services are bandwidth-hungry and require much more downstream capacity than upstream capacity. A cost-effective approach to delivering such services can be offered by combining digital broadcasting technology, for the high-capacity downstream links, with relatively low-speed mobile telecoms technology for the upstream links. The EU’s ACTS programme has made major contributions to enhancing the technology, and to providing visions of the mobile interactive broadband services that could be offered to customers during the next decade. This article offers an overview of those achievements. |
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| Interactive mobile streaming services the convergence
of broadcast and mobile communication |
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In this article, the authors discuss some of the challenges and opportunities resulting from the convergence of broadcast and mobile communication services. Starting with an overview of DAB, DVB and the emerging third-generation mobile communication networks – with a special focus on UMTS – the advantages that result from a combination of UMTS with data broadcast facilities, as provided by DAB and DVB, are discussed. This allows us to provide mobile users with interactive mobile IP streaming services, thereby opening the door for a lot of interesting mobile applications. The enabling of new services is not enough, however, if we take into account the limited spectrum allocation for mobile communication systems. Hence the article discusses the possibilities for efficient and flexible spectrum utilization. Mechanisms for dynamic spectrum and service allocation are introduced, which can be seen as a prerequisite, not only for efficient spectrum utilization, but also as an enabling technology towards more flexible communication services than we have today. |
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| DVB | |
| DVB-T transmissions interference with adjacent-channel
PAL services |
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In the UK, many of the new digital television (DVB-T) services are broadcast in adjacent channels to existing PAL services. There have been reports of PAL reception suffering as a result, possibly because the maximum DVB-T sideband levels have been incorrectly specified. This article describes how to calculate the PAL picture impairment arising from the presence of DVB-T sidebands. It also compares the calculated predictions with experimental data. The conclusion is that the sideband specification is correct: critical viewers would just notice worst-case interference. However, it is possible to misinterpret the specification. An allowance must be made for the difference in effective radiated powers between the DVB-T and PAL transmissions. An example is given of how a mistake could be made. |
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| Eurovision | |
| Eurovision network security through access
control and watermarking |
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| This study explores various issues that are important to transmission security on networks such as the EBU’s Eurovision network. The study will be presented in two parts - the present article introduces the problems associated with transmission security, and a second article (in the next issue) will detail the technical aspects of the proposed security system, based on EBU studies within the OCTALIS project | |
| MPEG-2 | |
| MPEG-2 4:2:2 and 4:2:0 comparative subjective
tests at low bit-rates |
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| This article reports on subjective test carried out by Swedish Television (SVT) in order to find a possible crossing point where MPEG 4:2:0 becomes superior to MPEG 4:2:2 encoding. The test were performed with the objective of extending the results reported in EBU Technical Review No. 279 to bit-rates of 5 Mbit/s and below. | |
| Bookshelf | |
| Video coding /// Speech and audio signal processing | |
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| * | Head of Publications and Internet Co-ordinator: | P. Jaquin |
| * | Editeur Responsable: | P.A. Laven |
| * | Editor: | M.R. Meyer |
| * | French Editor: | E. Piraux |
| European Broadcasting Union Case postale 45 Ancienne Route 17A CH-1218 Grand-Saconnex Geneva Switzerland techreview@ebu.ch |
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