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DRM update

DRM update. DRM Development. Sep 96 – Informal meeting between 5 broadcast-related organizations Apr 97 – 1 st formal meeting of Digital Radio Mondiale TM (DRM TM ) Mar 98 – 20 broadcast-related organizations signed the MOU in Guangzhou , as a first step to the official inauguration.

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DRM update

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  1. DRM update

  2. DRM Development • Sep 96 – Informal meeting between 5 broadcast-related organizations • Apr 97 – 1st formal meeting of Digital Radio MondialeTM (DRMTM) • Mar 98 – 20 broadcast-related organizations signed the MOU in Guangzhou, as a first step to the official inauguration

  3. DRM Development • Apr 2001 – DRM's has gained approval by ITU-R's members. The recommendation is now referenced as ITU-R BS.1514 and under standardization process. • Sept 2001 – the European Telecommunications Standards Institute (ETSI) published the technical standard for DRM’s on-air system. The document is called ETSI TS 101 980 V1.1.1

  4. DRM Development • Nov 99 – Evaluation group carried out field test • 2002 – DRM is an international consortium of 72 broadcasters, network operators, manufacturers • 2003 – DRM is scheduled to launch

  5. Digital AM System • iBOC • USA (MW) • In Band On Channel system, analog and digital Tx on same channel • Wider BW requirement than DRM • MPEG2 & OFDM

  6. Digital AM System • DRM • Europe (LW, MW & SW) • Tx on same band, different channels. • Simulcast is underway • MPEG4, QAM & OFDM

  7. IBOC Spectrum Fig 1 – AM Hybrid IBOC Spectrum Fig 2 – AM All digital IBOC Spectrum

  8. IBOC Spectrum Fig 1 – AM Hybrid IBOC Spectrum

  9. IBOC Spectrum Fig 2 – AM All digital IBOC Spectrum

  10. DRM Spectrum

  11. DRM Field Test • Phase 1 • Nov 1999 ~ Mar 2000, point to point SW and MF transmission. • Transmission path testing. • Phase 2A • Jul ~ Aug 2000 • Audio quality and reliability test

  12. DRM Field Test • Phase 2B • Dec 2000, broadcast in MF and LF bands. • 2001, transmission from Canada to Madagascar (13000km)

  13. DRM Field Test • Latest Test • 12 June 2002, Long-term DRM tests from Deutsche Welle and Radio Netherlands Bonaire, Netherlands Antilles are continuing. • The latest phase involves simulcast (analog/digital) mode. • Carrier frequency: 15530kHz

  14. DRM Field Test Commend • BBC – Compliance testing and specification validation  Clear, Complete and Unambiguous

  15. Features • Reinvigorate the use of frequency bands below 30 MHz – Short-Wave, Medium-Wave and Long-Wave • Improve sound quality, FM-like with the AM reach • Reduce interference by digital technique

  16. Features • Wider coverage due to improved S/N • Alternative frequency switching and Single Frequency Network • Value added services: • Program labels • Text messages

  17. Impact • Modification of existing transmission equipment is needed • New digital receivers is needed • Slightly reception improvement with existing output power • Better sound quality

  18. Coming Up • OFTA invite RTHK to conduct a DRM trial test in Peng Chau at 810 kHz

  19. Analogue Vs Digital

  20. DRM System • Non proprietary, open standard • uses existing AM broadcast frequency bands, 9 –10 KHz channel • Support SFN • Not support analog receivers • Simulcast is underway

  21. Technical Info • Audio: • MPEG4 Advanced Audio Coding (AAC) + Spectral Band Replication (SBR)  compressed audio: 20kbps / channel • RF: • QAM & ODFM (similar to DAB)

  22. Spectral Band Replication

  23. Digital Multiplex Audio Data Control signal MSC FAC SDC Multiplex

  24. World wide field test

  25. World wide field test

  26. 72 DRM-Members from 27 countries, 2002 Countries with DRM Members

  27. 16 QAM Constellation Change in amplitude and phase

  28. MPEG-2 AAC • a high quality audio coding standard for 1 to 48 channels at sampling rates of 8 to 96 kHz, with multi-channel and multilingual capabilities. • AAC works at bit rates from 8 kbit/s for a mono speech signal up to 160 kbit/s for very high quality. • Three profiles of AAC provide varying levels of complexity and scalability.

  29. MPEG-4 AAC • Coding and composition of natural and synthetic audio objects at a very wide range of bit rates • The representation for synthesized sound can be derived from text data or so-called instrument descriptions

  30. MPEG-2 AAC Vs MPEG-4 AAC • MPEG-4 AAC has all the tools and functions of MPEG-2 AAC plus the Noise Substitution tool, a Long Term Predictor as well as extensions to support scalability

  31. Useful Web Site • DRM: • official website: www.drm.org • www.ist-radiate.com • IBOC: www.ibiquity.com • MPEG: mpeg.telecomitalialab.com • ETSI Web site: www.etsi.org

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