DIGITAL RADIO MONDIALE DRM

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DIGITAL RADIO MONDIALE (DRM)
Intercontinental Hotel, Nairobi, Kenya 19th
December 2006
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Scope

• DRM Overview
• Digital Radio Paradigm shift
• DRM Standards
• DRM System features
• Spectrum implications
• Typical implementation DRM in Africa
• Merits for the broadcaster
• Demerits of DRM
• ChallengesLicensing issues

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1. DRM Overview

• A consortium of broadcasters and equipment
  manufacturers working to bring the benefits of
  digital broadcasting to the radio spectrum
• Currently used by terrestrial AM radio
  broadcasts, including international shortwave
  transmissions.
• Over seventy broadcasters are now transmitting
  programs using the new standard, known as Digital
  Radio Mondiale (DRM), and commercial DRM
  receivers are available.
• DRM's system uses the MPEG-4 based standard
  aacPlus to code the music and CELP or HVXC for
  speech programs. At present, however, these are
  priced too high.

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2. Digital Radio Paradigm shift

• Broadcast transmission as digital pipe
• DRM can cover 50M population from one
  transmitter!

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3. DRM Standards

• DRM is a new, open standard for Digital Radio
  transmission
• Published by ETSI (ES 201 980), and more
  recently through IEC
• Optimized for use in the HF, MF, LF bands
• Already recognised mandated by an ITU
  Recommendation
• Uses same channelling/spectrum as analogue

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4. DRM System features

• Single Frequency Network (SFN) support
• Multi-Frequency Network (MFN) support
• Up to four services in one multiplex usual
  metadata etc..
• DRM is an open standard
• Its very flexible
• Its very versatile

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5. SPECTRUM IMPLICATIONS

• DRM broadcasting can be done on different
  bandwidth in line with the GE 75 plans
• 9 kHz or 10 kHz which are the standard bandwidth
  of an AM broadcasting channel so existing
  frequency plan can be reused.
• 4.5 kHz or 5 kHz which are half channels. The
  idea is to offer a possibility for the
  broadcaster to do simulcast and use half a
  channel for AM and the other half for DRM.
  However the resulting bitrate and audio quality
  is less.
• 18 kHz or 20 kHz which correspond to a coupling
  of two adjacent channels. It offers the
  possibility to offer a better audio quality or to
  multiplex audio channels in the same transmitter.
  

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SPECTRUM IMPLICATIONS Cont
RF Channelling 4.5/5.0 kHz, 9.0/10.0 kHz,
18.0/20.0 kHz
9 or 10 kHz
DRM 1-channel
DRM 1-channel
DRM 1-channel
DRM 2-channel
DRM 1-channel
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SPECTRUM IMPLICATIONS Cont Basis of Automatic
Frequency Switching
If the same material is broadcast synchronously
on two frequencies, the receiver can use a period
of non-audio data to check an alternative
frequency
receiver is using f1 initially
DRM meta-data
Time
frequency f1
audio mux
audio mux
frequency f2
audio mux
audio mux
If f 2 is better, can switch at next gap.
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6. TYPICAL IMPLEMENTATION DRM Typical system
implementation of multiple services
DRM Modulators
Linear PA
f1
f2

f3
f4
F (MHz)
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TYPICAL IMPLEMENTATION ContDRM unique selling
points

• Cost of building analogue VHF/UHF networks to
  provide universal coverage prohibitive
• Even current public service broadcasters unlikely
  to achieve gt95 population coverage
• DRM can
• sustain service across remote areas
• Provide close to 100 geographical coverage

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Typical implementation Cont..DRM in Africa

• Example coverage on short-wave
• Tx 80W transmitter in Karisimbi, Rwanda
• In practice, to replicate analogue coverage, the
  average power requirement for a DRM transmission
  turns out to be 3 (/-3) dB less than the AM
  case.
• During the transition phase, the power of the
  replacement DRM transmission should be 7dB lower
  than the AM case to maintain an equivalent level
  of protection to the remaining AM services
  (Recommendation ITU-R BS.1615).

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7. DRM Merits

• Universal geographical coverage
• Nation-wide road systems even in
  rural/mountainous regions
• Complementary to higher-frequency digital
  systems
• DAB/DMB/DVB-H
• Universal modules chip-sets already develop
• Excellent spectrum efficiency
• One service per frequency, low-bit-rates, very
  flexible
• Can also provide Local and City coverage
• very similar to FM in terms of coverage

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DRM Merits Cont

• Allows broadcasters to provide service with a
  significant advance in audio quality and service
  reliability
• International broadcasters are able to provide SW
  MW which with DRM compare favourably with local
  FM services
• Local and international LW and MW broadcasters
  will benefit from enhanced audio quality and the
  ability to provide simultaneous data services

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8. DRM Demerits

• Its not magic still affected by man-made noise
  etc..
• Need to change frequency with time-not flexible
  for consumer

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9. Regulatory Challenges

• It is believed by industry that a greater public
  benefit should be realised if its introduction is
  planned rather than introduced prematurely while
  international developments are still occurring.

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Other Challenges

• Challenges associated with migration sunk costs
  for the broadcaster
• Costs of receivers for the consumer
• Receiver battery life

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Conclusion

• Content is King! Quality is Queen!
• DRM is a technology of the future and thus we may
  adopt a wait-and-see approach now

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THANK YOU