Digital Radio Mondiale (DRM)
2008-Q2	DRM field trials — for urban coverage planning in Spain
	Unai Gil, David Guerrar, Luis del Amo and Juan Masdeu (1189 kB)
	In 2007 the Spanish broadcaster Sociedad Española de Radiodifusión (SER) carried out DRM (Digital Radio Mondiale) experimental tests in close collaboration with other companies experienced in broadcasting: Vimesa Axión and the University of the Basque Country. This article sums up the results obtained from these experimental tests. Firstly, an introductory section describes the transmission and reception infrastructures. Subsequently, the test results are summarized in three sections: Simulcast, Monocast DRM and Monocast DRM Indoor Reception.
306	DRM — The BBC World Service distribution chain Julian Cable (416 KB)
	Broadcasters, both international and domestic, are busy turning their pilot DRM transmissions into real services. Meanwhile, the receiver manufacturers are trying hard to get their DRM radios into the shops as quickly as possible. This article gives an insight into the DRM distribution chain used by BBC World Service, which is made up of a mixture of professional equipment and in-house developments. Playing an important role in the BBC’s overall DRM strategy is the use of open-source software, wherever possible.
305	The AM Signalling System, AMSS — does your radio know what it is listening to? Andrew Murphy and Ranulph Poole (507 KB)
	The AM Signalling System (AMSS) adds a small amount of digital information to existing analogue AM broadcasts on short-, medium- and long-wave, giving similar functionality to that provided by the Radio Data System (RDS) on the FM bands. The system has been designed within the Digital Radio Mondiale (DRM) consortium, primarily to ease the transition from analogue to digital broadcasting. A suitably-equipped receiver will allow selection of the AM service by name as well as the choice of re-tuning to other frequencies carrying analogue or digital versions of the same or a related service. Several AMSS transmissions are already on air and some, if not all, of the first consumer DRM receivers will incorporate AMSS decoding.
296	DRM — a summary of the field trials James Briggs (771 KB)
	Field testing of the Digital Radio Mondiale transmission system has been in progress since 1999. This article reports on the results of these comprehensive trials which have included NVIS propagation near the equator, long-range propagation over distances up to 23,000 km, and tests with SFNs.
293	DRM — progress on the receiver front Peter Jackson (677 KB)
	The Digital Radio Mondiale (DRM) system provides a universal, non-proprietary, digital transmission system – designed to replace, eventually, the current analogue transmissions in the LW, MW and SW bands. This article provides information on the DRM receivers that were demonstrated at IBC- 2002 during September. It also oulines the work being carried out within a number of projects which aim to enable the early introduction of DRM consumer receivers.
291	CT-aacPlus — a state-of-the-art audio coding system Martin Dietz and Stefan Meltzer (186 KB)
	CT-aacPlus is a combination of Spectral Band Replication (SBR) technology – a bandwidth-extension tool developed by Coding Technologies (CT) in Germany – with the MPEG Advanced Audio Coding (AAC) technology which, to date, has been one of the most efficient traditional perceptual audio-coding schemes. CT-aacPlus is able to deliver high-quality audio signals at bit-rates down to 24 kbit/s for mono and 48 kbit/s for stereo signals. The forthcoming Digital Radio Mondiale (DRM) broadcasting system, among others, will use CT-aacPlus for its audio-coding scheme. CT-aacPlus will enable DRM to deliver an audio quality, in the frequency range below 30 MHz, that is equivalent to – or even better than – that offered by today’s analogue FM services. This article describes the principles of traditional audio coders – and their limitations when used for low bit-rate applications. The second part describes the basic idea of SBR technology and demonstrates the improvements achieved through the combination of SBR technology with traditional audio coders such as AAC and MP3.
286	DRM — key technical features Jonathan Stott (344 KB)
	Digital Radio Mondiale is a system which promises to re-invigorate the use of the broadcasting bands below 30 MHz. It offers a dramatic improvement in audio quality, not only improving the audio bandwidth and signal-to-noise ratio, but also countering the effects of selective fading and audible interference from other stations. It is also designed to support various features that will make receiver operation more user-friendly. This article describes the basic “mechanics” of DRM and its features, which include station identification, alternative frequency lists and support for time-varying frequency schedules – of particular importance in HF broadcasting..
286	DRM — implementation issues Mike Cronk (185 KB)
	Implementing a new technology around the globe is not straightforward. History provides us with few examples of a successful roll-out on day one of a global launch – with perhaps the exception of some new electronic toys. To penetrate new markets, even on a small scale, is a challenge for any organization involved in bringing a new product to market. Multiply this by the vast range of different market conditions that a new technology – with global aspirations – will face, and it becomes a serious issue. This article talks about some of the challenges facing the launch of Digital Radio Mondiale (DRM) and the route that is now being planned to enable the implementation to be a successful one. It focuses particularly on the end listener, and the issues that will be faced by DRM in getting this new digital service to the consumer.
Digital Television (General)
306	An introduction to revenue sharing Kris Van Bruwaene (246 KB)
	Sharing the revenue between content providers and network operators is a recurring problem in media business modelling. It is generally a matter of negotiation between the parties, but those negotiations often lack a clear basis and have limits. This introduction will try to determine the limits of “fair, reasonable and non-discriminatory” revenue sharing, based on a simplied model. It does not presuppose any economic expertise from the reader.
302	The challenge of QoS for digital television services Denis Abraham, Dominique Méry et al. (253 KB)
	Quality of Service (QoS) in digital television broadcasting has been the subject of many studies during the last decade. This has led to the establishment of various standards and recommendations by organisations such as ETSI and the ITU. More than twenty relevant parameters and associated measurement methods have been specified by ETSI for DVB but their interpretation, usage and exploitation are often considered “difficult” – in that they require a high level of expertise. This article describes how three “synthetic” parameters (SAE, SDE and SIE) have been developed to make assessment of QoS considerably easier. They could represent the keystone of QoS in digital TV services.
269	Television in the digital era George T. Waters (145 KB)
	The Royal Television Society recently opened one of its Centres in the Republic of Ireland and the inaugural lecture was given by Dr. George T. Waters (Technical Director, EBU). This article summarizes Dr. Waters' lecture which was delivered at the University College, Dublin, on 15 May 1996.
268	World Vision 2000: a proposed worldwide forum on the emerging television environment M.I. Krivocheev (76 KB)
	Beginning with the observation that broadcasting is at a critical point in its development – with the adoption of digital technologies for programme – making and delivery, and increasing competition in all sectors of the industry – the Author states the case for the establishment of a worldwide forum on interactive multimedia television broadcasting. Known provisionally as "World Vision 2000", the forum would bring together all the major industries claiming a stake in the audiovisual markets of the 3rd millennium. World Vision 2000 would draw back from the situation and ask questions on how convergence can be made to happen, how the new media will shape society, and how to help the world become less of a place with information "haves" and "have nots". Above all, the forum would be an opportunity for broadcasters, the computer and telecommunications industries, publishers, and others from the developed and developing countries to lay open the fears and promises of digital television and to try to understand the new environment.
266	A functional model of a conditional access system for use with digital television broadcasts EBU Project Group B/CA (76 KB)
	EBU Project Group B/CA has developed a functional model of a conditional access system for use with digital television broadcasts. It should be of benefit to EBU Members who intend to introduce encrypted digital broadcasts; by using this reference model, Members will be able to evaluate the different conditional access systems that are available. The model is not intended as a specification for a particular system. Rather, it provides a framework for defining the terms and operating principles of conditional access systems and it illustrates some of the conflicts and trade-offs that occur when designing such systems.
264	Digital broadcasting demonstrations by HD-SAT and dTTb at Montreux '95 A. Oliphant and L. Combarel (82 KB)
	Two RACE projects on show at Montreux '95 – HD-SAT and dTTb – gave the first complete integrated demonstration of MPEG-2 digital television broadcasting – terrestrially, by cable and by satellite. Visitors to the stand were able to watch four widescreen SDTV or one HDTV programme being broadcast in an 8 MHz UHF channel, in a single-frequency network. Another demonstration showed a very high-quality HDTV programme being broadcast via a satellite channel in the 20 GHz band, with a fallback operation which allowed graceful picture degradation if the HDTV signal could not be received satisfactorily due to heavy rainfall. A third demonstration showed the terrestrial and satellite signals being broadcast, without loss of quality, over the Montreux cable television network.
259	A Global Approach to studies in television broadcasting M.I. Krivocheev (145 KB)
	Detailed technical investigations are in progress, worldwide, concerning new television broadcasting systems. These range from relatively simple enhancements of today's systems, to futuristic concepts for digital stereoscopic and 3-D HDTV. It is necessary to establish a clear view of the opportunities presented by these varied developments, and the time is right to formulate the tasks and strategies that will pave the way into the 21st century. The world forum for standard- setting in this field is the ITU Radiocommunication Sector (ITU-R), and Study Group 11 (Television broadcasting) in particular. Here, in a wide- ranging reflection on options and opportunities for the immediate and longer-term future, the Chairman of Study Group 11 first outlines the work now being carried out within the ITU. There follows a discussion on the new approaches and strategies that characterize the forthcoming Study Period (1994-95), and on the challenges that lie ahead.
256	European perspectives in digital television broadcasting — Conclusions of the Working Group on Digital Television U. Reimers (97 KB)
	In Europe, a coordinated activity was started in early 1992, which aims at the design of a common system for digital television broadcasting. Under the auspices of a European Launching Group composed of members of eight countries representing a range of organizations involved in the business of television, the Working Group for Digital Television Broadcasting (WGDTB) has defined system approaches for such a digital service. The findings of the WGDTB are reported and the three systems proposed for study and future implementation are presented. All three are multi-layer systems, which include two or more service levels which are inter-related either in a hierarchical or in a multicast mode.
256	European perspectives in digital television broadcasting — Quality objectives and prospects for commonality D. Wood (44 KB)
	In Europe, a series of collaborative projects are developing elements of digital terrestrial and satellite broadcasting systems. Efforts are being made to encourage these projects to work towards a common standard for Europe. The article outlines some of the proposals already made for an initial target system. Particular explanations are given of the current quality goals, and how they were established. Other issues considered are coverage problems, commonality of terrestrial with satellite, common multiplexing, and conditional access.
256	European activities on digital television broadcasting — From company to co-operative projects B. Marti, N. Lodge, P. Bernard and R. Schäfer (88 KB)
	This contribution focusses mainly on the channel aspects of some European digital television projects, the source coding aspects being dealt with mainly in the framework of a larger standardization effort within MPEG. The channel-related studies in Europe take account of a particularly difficult situation as regards frequency planning, and are aiming at single frequency networking as a means of achieving maximum economy of frequencies. Continuing the approach adopted for Digital Audio Broadcasting, COFDM is the favoured system in Europe and is the basis of the digital terrestrial television broadcasting (dTTb) project funded by the European Commission. The first results are very encouraging, although the feasibility of portable reception – a specific feature of terrestrial broadcasting that cable and satellite systems cannot offer – remains to be fully established.
256	Digital multi-programme TV/HDTV by satellite M. Cominetti, A. Morello and M. Visintin (276 KB)
	The progress of digital technology since the WARC'77 is considered and the perspectives of future applications via satellite channels are identified. Among these, digital multi-programme television systems, with different quality levels (EDTV, SDTV) and possible evolution to HDTV, are evaluated in terms of picture quality and service availability on the satellite channels of the BSS bands (12 GHz and 22 GHz) and of the FSS band (11 GHz) in Europe. A usable channel capacity of 45 Mbit/s is assumed, as well as the adoption of advanced channel coding techniques with QPSK and 8PSK modulations. For high and medium-power satellites, in operation or planned, the receiving antenna diameters required for correct reception are reported. High-level modulations (16QAM, 32QAM, 64QAM) are considered for distribution of the satellite signal in cable networks.
256	Digital broadcasting of studio-quality HDTV by satellite in the 21-GHz frequency range and by coxial cable networks C. Dosch (167 KB)
	Backed up by extensive research and demonstrations, the frequency band 21.4 - 22 GHz was finally allocated to the broadcasting satellite service by WARC-92. The band is intended to be used for near studio-quality digital HDTV with associated multi-channel surround sound. Digital transmission can cope with the propagation conditions in this band, which are more difficult than those encountered in the 11 or 12 GHz downlink bands, and allows more flexibility for frequency planning than analogue schemes. In cable networks, digital multi-level modulation permits the use of relatively narrow-band transmission channels. The article gives an overview of the current state of development.
Digital Television (terrestrial)
2008-Q3	DTV transmitter power efficiency – new opportunities for reducing costs and environmental impact
	Keith Pruden (587 kB)
	The worldwide introduction of digital terrestrial TV systems will lead to significant numbers of new transmitters being installed over the next few years. With the recent rise in energy prices, and increasing concerns over the environmental impact, it is important that these new transmitters are as energy-efficient as possible. This article discusses various issues relating to the power efficiency of digital TV transmitters, and describes how Envelope Tracking technology could make a significant contribution to reducing the operational costs and environmental impact of new digital networks.
2008-Q1	The roll-out of DTT in France — not just SD ... but HD and mobile TV services as well
	Aurélien Louis and Matthieu Roger (491 kB)
	Despite the rather late launch of DTT services in France compared to some neighbouring countries, they are already being adopted widely by the viewers, thanks to a long tradition of terrestrial television reception. By increasing the number of services and the transmission quality, the digital television landscape is maintaining its rapid evolutionary pace. This article gives a brief description of the current DTT situation in France and of its soon-to-come evolution: HDTV and mobile TV launches. In the longer term, terrestrial broadcasting networks will develop further, as a result of a national scheme to re-allocate the frequencies freed up by the digital switchover process.
295	Field evaluations in Taiwan of the DVB-T COFDM and ATSC 8-VSB digital TV systems Chi-Fang Huang, The Nan Chang and Chau-Yun Hsu (1106 KB)
	This article presents the results of field evaluations carried out in Taiwan on the two principal digital TV broadcasting systems in use today – ATSC 8-VSB (developed in North America) and DVB-T COFDM (developed in Europe). The evaluations were carried out in February and March 2001 in the Northern area and the Taipei metropolis of Taiwan. Based on the subsequent report (which forms the basis for this article), the Taiwan telecommunications authority agreed to deregulate DTV broadcasting and adopt the DVB-T transmission standard. DVB-T is now being used by the five terrestrial television broadcasters in Taiwan.
273	The inductive output tube — The latest generation of amplifier for digital terrestrial transmission Roy Heppinstall, Graham Clayworth (576 KB)
	The inductive output tube (IOT) is the latest generation of amplifying device for use in high-power transmitters. It entered service in 1991 and is now used world-wide as a more efficient replacement for the klystron at UHF. The performance of the IOT in analogue television transmitters is outlined here. The article also presents and discusses the results of its performance as the final amplifier in the new generation of digital terrestrial television transmitters.
270	Digital television comes down to earth Stan Baron and David Wood (55 KB)
	In this article, the Authors provide a progress report on the world-wide studies of digital terrestrial television broadcasting, carried out by ITU-R Task Group 11/3. The final meeting of Task Group 11/3, held in Sydney during November 1996, was highly productive and extremely successful. International agreements – defining a complete digital terrestrial broadcasting system – were finalized. The Reports and Recommendations (standards) have now been forwarded to the parent bodies of Task Group 11/3 for formal approval, which is expected later this year (1997).
260	The conventional planning approach applied to digital terrestrial television K.J. Hunt (94 KB)
	This article continues and expands upon the discusion started in [3]. It is becoming ever more clear that the future of broadcasting, and that of television in particular, is digital. The transfer to digital is already taking place in the studio; many contribution circuits are already digital; the final stage in this process involves the transmission and reception part of the overall chain. The potential benefits are considerable. The greater spectrum economy of digital signals will provide the capacity for more services, while also providing higher technical quality for the pictures displayed in viewers' homes. The main difficulty lies in finding the spectrum in which to introduce the digital services, while maintaining the existing analogue services in operation for what could be an extended transition period.
257	Planning aspects of digital terrestrial television G. Petke (146 KB)
	New bit-rate reduction techniques and the development of powerful modulation schemes offer the possibility of squeezing one or even more digital television programmes into an 8-MHz wide television channel. The article gives an overview of the availability of frequency bands, including the use of the so-called "taboo channels". The situations in Europe and the United States are compared. Protection ratios and minimum usable field-strength values, including margins for reliable operation of a digital service, are discussed. Using the OFDM technique, a digital service can be operated as a single-frequency network. It is shown that in addition to frequency efficiency, the SFN offers further advantages compared to other approaches.
257	Planning for terrestrial digital television K.J Hunt and R.I. Black (155 KB)
	This article is intended as a companion to that prepared by Mr. Petke and which also appears in this issue of EBU Technical Review. It describes some of the work being undertaken within the general area of EBU Sub-group R2 and, in particular, its Specialist Group R2/DTV. The latter was set up specifically to study the possibilities open to digital television transmission in the bands allocated for terrestrial use by television services. It has rapidly been established that there are short-term as well as long-term possibilities. In the short-term, the limitations imposed by the need for coexistence between analogue and digital services give rise to difficulties which must not be underestimated. In the long term, almost everything seems to be possible!

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