WWORD-145 от 08.12.2007

This programme I devote to Digital Radio Mondiale (DRM) theme.

On November 27-th, the DRM meeting was held in Kyiv, Ukraine. The meeting was organized by Deutsche Welle DRM team and the Concern of Radio, Radiocommunications and Television (RRT) of Ukraine.

The Digital Radio Mondiale (shortly DRM) is the digital broadcasting system for the broadcasting bands below 30MHz (long, medium and short waves). It has been endorsed by the International Telecommunication Union (shortly ITU).

While DRM currently covers the broadcasting bands below 30 MHz, the DRM consortium is extended the system to the broadcasting bands up to 108 MHz. This system extension has the internal project name DRM+. On the same day with the meeting in Kyiv, DRM was also approved by ITU for tropical band shortwave broadcasting.

The first presentation in Kyiv was made by Peter Senger, DRM-Chairman, Deutsche Welle Director on DRM. He noted that the digital transmission system for long-, medium- and short-waves (from 150 kHz to 30 MHz) is ready for usage, and the extension up to 108 MHz is now under test. Among the well-known advantages of DRM for listeners are the following: the receiver tunes on station name, though frequency is not known, and switches automatically to the best frequency without interruption.

The DRM consortium includes now 106 DRM members from 34 countries, and 76 DRM supporters from 21 countries. Unfortunately, Ukraine is not represented in these numbers.

The commercial radio station RTL from Luxemburg rates first in terms of the amount of DRM broadcasting hours per day, it occupies almost 90 hours from the total 737. Then, Deutschlandradio with Deutschlandfunk broadcast about 50 hours per day, and then in descending order: Telediffusion de France, Deutsche Welle, BBC, Voice of Russia, and the others.

The DRM system features up to 4 services on each frequency: each service consists of radio programme (audio) plus DRM text messages and multimedia applications.

But the DRM receiver situation is most interesting for radio listeners. So I will dwell on this question in more detail.

Today all receivers are based on a Digital System Processor, or computer. And this computer includes a chip which costs 50-60 dollars. Therefore this radio cannot be cheap; it must cost about 150 euro. The Fraunhofer institute in Hannover has developed the chipset, and together with ST Microelectronics from Italy they can soon fabricate it. That chipset will be made of silicon wafer which includes 1000 chips, each of them costs about 1 euro.

The well-known is now Radioscape RS500. It is the world’s first multistandard DAB/DRM software radio module developed in the UK, which enables to receive stations on DAB band III and L-band, DRM and AM stations on AM bands from 150 kHz to 30 MHz, FM stations. RS503 module is planned.

As to DRM receivers in the full sense, which are available now, they were presented in the Peter Senger presentation by Morphy Richards, Starwaves HiFi-Set Surround Sound, Digital Wave Traveler, and Himalaya 2009, made in Hong Kong . The receivers available in 2008 will be Himalaya 2008, the Russian receiver Orlyonok, Roberts (Sangean) MP40, Bosh-Blaupunkt multi-band car receiver, TechniSat multi-band receiver, and ADI prototype DRM receiver (BlackFin) from India. The company Kenwood is interested in the production of car DRM receivers too. The new antennas for cars were tested.

Two receivers were presented at the meeting in Kyiv: Himalaya 2009 and Orlyonok. Both receivers ensure reception in DRM and DAB modes, on FM, Long-, Medium- and Shortwave bands. Himalaya 2009 is similar to a contemporary carrying stereo set, and Orlyonok is done in the mono retro-style. But it is interesting that at the Kyiv meeting Himalaya 2009 rather long time was incapable to receive any DRM station, unlike Orlyonok, which coped with such task easily – it was able to receive Deutsche Welle on 15725 kHz. For example, here is the recording of the Deutsche Welle programme in English, directed to Europe (Sorry that the recording was spoiled by voices of the meeting members):
(Audio)

But some moments later, Orlynok began to “stammer”, and the sound disappeared.
(Audio)

Nevertheless, towards the evening, the Himalaya awaked and received Radio Netherlands with excellent quality. Then Peter Senger handed it with a solemnity to Anatoliy Antonenko, who is the President of the Concern RRT and the host of the DRM meeting.

The second presentation was made by Albert Waal from the Hannover University. The first part of his lecture was about DRM technology for the local broadcasting in the towns with high population density on the 26 MHz band, that is 11 meterband. The term “local” is applicable to a range of about 50 kilometers from a transmitter.

DRM here uses the narrow band multiplex system with 10 kHz frequency band for 1 channel and the bit rate of up to 26 kilobit per second, which allows transmitting on it 4 programmes simultaneously. In the range from 25.67 to 26.1 MHz the 43 DRM radio channels go in.

The peculiarity of this band is a lesser man-made noise than on Medium Waves, but, unfortunately, there is a possibility of interference from remote radio stations due to ionospheric reception in the period of high sun activity and sporadic propagation via Es layer of ionosphere. To avoid this kind of interference, 2 frequency transmissions of the same programme with two transmitters were offered, or another method: 1 transmitter can be automatically retuned from the interfered frequency to another one in 2 seconds, and so does the receiver.

The broadcasting on 26 MHz band is already available in Europe. The HFCC frequency list B07ALL has 22 frequency allocations occupied by broadcasters from the Great Britain, France, Germany, Luxembourg, Vatican and even Bulgaria.

In the second part of his lecture, Albert Waal told about digital broadcasting on FM bands. Now there are 3 systems of such broadcasting: HD-Radio, FMeXtra and DRM+. The latter is more preferable.

The system DRM+ is intended for Hi-Fi broadcasting on the first TV band from 47 to 68 MHz, on the East European UKW band from 66 to 74 MHz, on Japanese FM band from 76 to 90 MHz, and on World FM band from 87.5 to 108 MHz. This system needs only about 96 kHz frequency space, which is lesser than that of analog FM signal with its 250 kHz space, and of HD-Radio with 400 kHz. Four stereo programmes with the data and the data rate of 186 kilobit per second can be transmitted on one channel. This system is independent, flexible and meets the needs of local broadcasting.

FMeXtra system is analogue, not digital. The data rate is from 40 to 48 kilobit per second. It is not perspective system.

That was the first part of my information about the DRM meeting in Kyiv. In the next issue of WWORD I’ll continue it.