|DIGITAL RADIO MONDIALE, DRM
By Chris Gill
Summary of lecture given at the conference of the National Association of Shortwave Broadcasters, USA, November 2000
Published in the Electronic DX Press
Considerable uncertainty exists as to
which emerging technologies are likely to succeed for a sustained
period. We can be certain of some things as regards the future
of broadcasting: the choice of new technologies will be even greater
in the future than it is today; in most markets, the listener
will be increasingly tempted by improved audio quality; however
good the content, the listener will also be looking for choice;
of all the new technologies offered, some will not succeed. The
challenge facing international broadcasters is making the right
choice. In the past, it was possible to compete (mostly with mediumwave
and shortwave) on the basis of the quality of the content of a
broadcast, with audio quality being a secondary issue. In the
future, expectations will be for a higher level of audio quality.
With the proliferation of outlets for programs such as FM, cable, the Internet, and satellite, we must form a reasonably accurate view of how our listeners will access our "content" in the future. Many believe that satellite and the Internet will be the major "content" providers of the future. With the wide choice of "content" available, broadcasting is moving more and more into narrowcasting, with content tailored to specific interests. The Internet, in particular, offers the possibility for self-assembled, on-demand personalised content. However, radio will continue to be a significant means of getting audio to the listener for many years to come. However much the choices may expand, whatever the range of new technologies available, there will still be many occasions during the day when we can't look at a screen, or sit down at the computer, or use the Internet types of technology. Radio still fills an important gap.
Mike Cronk (of the BBC and DRM) suggests that radio of the future should meet these criteria: easy operation for the listener; simple designations for different "channels"; possess good audio quality with good dynamic range; economical transmission requirement; the signal must cover a large land mass without reception being hampered by obstructions such as hills or buildings; fading and interference must be minimised; broadcasters should be able to control the "gateway"; maximise use of previous investments and minimise costs of required new investments; receivers shouldn't be much more expensive than present receivers; must be workable within present spectrum allocations.
In March 1998, a group of broadcasters, transmitter and receiver manufacturers, network operators, and research bodies signed a "Memorandum of Understanding" to develop a system with characteristics as described above. Later that year a formal consortium agreement was completed, putting in place a body committed to the development of a digital standard for the AM bands below 30 MHz. Digital Radio Mondiale (DRM) was established.
The DRM Technical Committee, working in a very tight time frame, developed a standard sufficiently robust to submit to the ITU. Also, they conducted a series of propagation tests using five converted transmitters around the world. These tests were for the purpose of proving that the theory would work out in practice. In future months, the DRM will be encouraging adoption of the proposed standard, as well as continuing the more detailed development work, and testing the system.
Estimates from the transmitter industry indicate that modern transmitters could be converted to digital at a cost of about $100,000 per transmitter.
They aim to have digital receivers in the marketplace in late 2001 or early 2002. One of DRM's goals is that a receiver bought anywhere in the world will work anywhere in the world. For this to succeed, it is important that a standard emerges from the work of the ITU that meets the needs of the broadcasting industry around the world. As a result, DRM has started to work with USADR to promote the adoption of a global standard. This will reduce the cost of new receivers and make the product more attractive to the consumer.
Gill's research indicates that there are an estimated 2.5 billion receivers in the world, of which 60% are estimated to have shortwave on them. In the ITU listings, there are 169 organisations using HF on a wide scale, broadcasting from 593 locations around the world.
Although it may not be possible to arrive at a single world-wide standard for digital broadcasting, it is hoped that there will be sufficient coordination that a single receiver will be capable of receiving any of the systems that get into actual use.
One very possible development of the near future is a single portable device that will provide music, news, commentary, e-mail, web-access, video, and such, all via digital transmission. If broadcasters are not fully on digital platforms, they may not be part of this delivery system. DRM is an opportunity for broadcasters to achieve that digital presence.
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East Broadcasting Company, Herald Broadcasting Syndicate, High
Adventure Ministries, LeSea Broadcasting Corporation, Radio Miami
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