digital radio for all

The Digital Radio
Mondiale (DRM) Standardecnalgat a

What is the Digital Radio Mondiale (DRM) Standard?
DRM digital radio is the global standard that can uniquely offer new broadcasting services to local, regional,
national and international audiences. It is the newest, most complete, and internationally recognised system fordigitising radio in all frequency bands. This means broadcasting radio programmes on short, medium and longwaves (AM frequencies), as well as in the VHF frequencies – usually in the FM bands. DRM brings radio in the 21stcentury ensuring its continued future.
▶ DRM is a non-proprietary, open standard (no company owning the technology), which can be implemented byanyone. It is recommended and endorsed by relevant international organisations such as ITU and ETSI.
▶ The DRM standard allows for transmissions of up to three audio signals, plus data, within one single frequency
as compared with the analogue system which only allows one programme per frequency. This means that DRM
digital radio uses spectrum very efficiently.
▶ Broadcasters can operate their own independent transmitters without having to share with potential competitorsa large multiplex, which is usually operated by a paid third-party organisation.
▶ In addition, the DRM standard in the FM band allows several broadcasters to share the same transmitter andantenna that can carry multiple DRM signals side by side, thus reducing the operating costs and becoming truly
green. Those broadcasters still remain in control of their own broadcasts.
▶ Many existing analogue transmitters can be converted in some instances to digital DRM at relatively modest
costs, while retaining all associated infrastructure, including antennas.
▶ Information, emergency warnings and alerts, education and entertainment can reach every single listener in acountry, regardless of its size and geography, thus fulfilling governments’ mandate to make information (andeducation) accessible to all citizens regardless of where they live.

Unique Advantages of the DRM Standard
DRM IS AN OPEN STANDARD
Apart from the ability to fit in with existing spectrum requirements, the DRM system also benefits from being anon- proprietary open system, in all parts of the broadcast chain. This means that all manufacturers andinterested parties have free access to the complete technical standard and can design and manufacture
equipment on an equitable basis. This is a significant consideration for broadcasters investing in DRM
infrastructure, manufacturers investing in receiver development and production, and even more so for thelisteners who will need to invest in the new DRM-capable receivers.

May 2023

DRM COMPATIBILITY WITH EXISTING FREQUENCY ALLOCATION AND REGULATIONThe DRM broadcasting system has been designed specifically as a digital high-quality audio replacement for
current analogue radio broadcasting in all the AM and FM/VHF bands; as such it can be operated using thesame existing channel and spectrum allocations as currently used by broadcasters in the analogueenvironment.
An overview of the frequency-bands where DRM operates is shown in the figure below.

LF

HF

MF

FM

DRM in
VHF

DRM in AM bands

1 MHz

10 MHz

DRM

DRM

AM

100 kHzUHF

VHF

100 MHz

1 GHz

There are two variants or modes of the DRM standard:a. DRM for wide coverage (in red) for the short, medium and long wave bands below 30MHz(sometimes known as DRM30), replacing analogue Amplitude Modulation (AM)b. DRM for local coverage (in blue) using the VHF bands above 30MHz (sometimes known as DRM+)
replacing analogue Frequency Modulation (FM)DRM is one standard and its features and benefits are the same in both modes(AM and VHF bands)

The way in which signals propagate at different frequencies is the same for DRM as for existing analogue
transmissions. This will range from short wave frequencies that can cover very long distances over any type ofterrain, to VHF that is meant for local coverage. This is illustrated below:

serves all coverage needs

AM bands
Large areacoverage

HF, (MF at night) – many 1000s km

MF daytime – many 100s km

VHF band II (FM)many 10s km
VHF band III
line of sightVHF (FM) bands
Local coverage

www.drm.org

The Digital Radio Mondiale (DRM) Standard | at a glance

The diagram illustrating the coverage needs can be summarised in the following way:a. Medium and Long Wave. Depending on transmitter power, local and regional transmission can beprovided for longer distances of up to 1000km.
b. Short Wave supports large areas for both national and international transmission. See the schedules atwww.drm.org for details of current international and some national broadcasts.
c. In the VHF bands (mainly in FM Band II, but bands I and III can be utilised as well) DRM allows local
broadcasters to be highly focused on smaller areas addressing local communities. In the VHF frequencies,DRM for local coverage can support two or more transmitters with overlapping coverage using the same
frequency. This greatly enhances coverage while not using more spectrum. It is a technique (not available inanalogue) known as the Single (or Multiple) Frequency Network (SFN or MFN), as illustrated below

DRM SFN – Gap Filling

Two or more transmitters broadcasting:
1 The same content
2 At the same time
3 On the same frequency

SMOOTH TRANSITION FROM ANALOGUE TO DRM DIGITAL TRANSMISSION
During the transitional period from analogue to digital, transmitters can broadcast in DRM while still putting out
existing analogue signals for existing analogue radio sets. This dual transmission method is called Simulcast. It
is highly recommended that this period be as short as possible.
Broadcasters can determine their own migration path to digital transmission by exploring how the simulcast
mode will work best for them. One of the options is to broadcast from the same transmitter in both theanalogue and digital modes at different times of the day. The other option is to broadcast the same programme
both in analogue, as well as in DRM, during the same period of the day by splitting the transmission power
between analogue and digital. This may affect the coverage area. Therefore, in the transition period, it isrecommended to use option one, so that the coverage area is not affected.

The Benefits of the DRM Standard
COVERAGE FLEXIBILITY
DRM, by using all frequencies, allows large, medium sized and smaller broadcasters to use effectively thefrequencies best suited to target their interest region and audiences. No other digital open standard can dothat.
a. Therefore, DRM is ideal for smaller broadcasters wishing to transmit programmes to listeners in certain areasof choice and in a certain language or dialect, whereas another ‘neighbouring’ broadcaster can target awww.drm.org

The Digital Radio Mondiale (DRM) Standard | at a glancedifferent area and listener group using theother languages or dialects of that region
without interference. This scenario is true
for communities being serviced bycommunity stations using the DRM
standard in the FM band.

DRM
coverageb. By contrast, larger commercial
broadcasters or national broadcasters
may use DRM in the AM bands (likemedium wave and shortwave) to coverlarge to very large areas of a country. It
can be very expensive to equip andmaintain many FM transmitters deployed
for covering large areas. Therefore, one
DRM shortwave or medium wave
transmitter can provide the necessarylarge area coverage, as illustrated here. The small circle shows the localised FM coverage, whereas the large
circle illustrates the very large area by using DRM in medium wave.

ENERGY EFFICIENCY
Broadcasters benefit from reduced power
consumption in digital DRM of between 50%
and 80%. DRM transmitters use significantly
less power than analogue ones in both theAM and FM frequencies. Here is an example ofa comparison between the analogue and thedigital DRM efficiency in the VHF band. If in
the traditional analogue FM mode
broadcasters need a 10kW transmitter for justone programme to cover some 70km ofdistance, in digital DRM 1kW transmitter issufficient to broadcast three audio
programmes, plus a data channel, to cover thesame geographical area.

Coverage and Power Consumption DRM ←→ FMFM
1 audio programme

DRM in VHF

1 data channel
3 audioprogrammes

10kW

10 : 1 power(up to 100:1Optimum conditions)

1kW

SUPERIOR SOUND QUALITY WITH THE LATEST AUDIO CODING TECHNOLOGYDRM delivers for the first time Short Wave and Medium Wave broadcasts in FM-like mono or stereo soundquality without the noise and distortion of analogue, in the home or in the car. Local digital broadcasts (of FMstations) also enjoy superior surround sound without fading or crackling. DRM is so far the only global digitalstandard which can use the latest audio codec xHE-AAC at low to very low bit rates being thus aligned to themobile industry.

BROADCASTERS CAN OFFER MORE CONTENT CHOICE
DRM has the potential to bring new, exciting content and more programmes on one single frequency while
delivering spectrum savings, as already mentioned. In the FM bands for instance, DRM uses half the current
stereo FM spectrum (100 kHz and not 200 kHz), whilst offering reduced transmission power, increased
coverage, and additional programmes and services.
These new programmes, complemented with multimedia content, can be made available in several languages
and/or dialects. Whether the programmes are broadcast in DRM in the AM or VHF bands, listeners can staytuned to the same station, without loss of signal, as they cross regional or national or even internationalboundaries. DRM allows also important traffic information to be broadcast when necessary.

www.drm.org

The Digital Radio Mondiale (DRM) Standard | at a glanceEMERGENCY WARNINGS AND ALERTS (EWF)
DRM enables the delivery of emergency and alert programmes containing both audio and text in several
languages/dialects simultaneously. The Emergency Warning Functionality (EWF) is an integral part of thestandard and radio receivers can also function as EWF alert points. The DRM digital radio can be woken up ifin sleep mode by the emergency signal. The picture below illustrates how a transmitter (blue) outside of thedisaster area (light green) can transmit information to the digital receivers about the situation in the disasterarea.

DRM EWF – Functional Overview
Digital Radio EWF –Emergency Warning Feature

Emergency alerts sent toall digital radio receivers
in the affected area
Supporting
long-distance
EWF coverage
from outsidedisaster area

Emergency Information
can be broadcast in

Affecteddisasterarea
1

any language or
dialect in both audio
and text on screen

Receiver switches on and/or retunes automatically

2 Visual/acoustic signalling
3 Alarm announcement and multi-lingual look-up text instructions via
Journaline (serving non-native speakers and the hearing impaired)

DRM IS NOT DEPENDENT ON THE INTERNET OR ELECTRICITY SUPPLYThe DRM radio is an advanced modern product which does not require an internet connection or a Wi-Fi spotfor tuning in. It is portable, therefore mobile, and can be used with long lasting batteries (up to 12 hours ormore), too. However, DRM can bring to the listeners the content of internet (RSS feeds or through theenhanced text messages system called Journaline) on the larger radio screens.

DRM ALLOWS THE CREATION OF JOB OPPORTUNITIES AND OF REVENUE STREAMSFOR KEY STAKEHOLDERS
DRM means additional digital services, which can generate new revenue streams (through advertising, as well)without compromising the existing content offer. More varied content means also more journalistic andtechnical jobs at the actual radio stations. There are opportunities in software and R&D development,
distribution, retailing and a new kind of journalism.
The DRM digital radio standard is a strategic opportunity for the local industry to increase their businesses andprofits.

www.drm.org

The Digital Radio Mondiale (DRM) Standard | at a glance

The local production of DRM radio receivers for desktops, tablets, laptops,for mobile phones and especially cars ensures new jobs and wealth creation.

DRM Implementation Considerations
A clear decision needs to be taken about the introduction of the DRM standard in a country. Then the major
stakeholders (the Ministry, the Regulator, the Public Broadcaster, the commercial and community broadcasters,
the manufacturing industry) need to come all together and plan the roll-out of the DRM digital standard by first
deciding a “launch-date” of digital radio in the country (not to be mistaken with a switch-off date, which may
happen much later, meaning the complete replacement of analogue transmissions by the digital ones!).
The launch date needs to be communicated very clearly to the manufacturing industry first and then toretailers, as they need to have the certainty that DRM digital radio will be firmly launched and rolled out. The
manufacturers need to plan the production of radio receivers (whether desktops, in cars or in mobiles), produce
them and, in co-operation with retailers, make them available in shops. Listeners also need to be informed about
the impeding roll out of digital radio but only a few months before the actual digital radio launch, so that they getfamiliar with the new modern radio technology and learn about the benefits of digital radio. They need to getexcited about the prospect of buying such advanced receivers in shops. And when they decide to do that, thosereceivers must be available.

For more information on the DRM standard, its features, and benefits, please visit our website atwww.drm.org and access freely the full DRM Handbook (handbook.drm.radio).
For a detailed technical insight and access to proprietary information, as well as additional benefits
and implementation steps, we would recommend any potential stakeholder to join the DRM
Consortium, thus being able to participate in our special events and network opportunities.
Please contact us by email at: projectoffice@drm.org

www.drm.org

The Digital Radio Mondiale (DRM) Standard | at a glance