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Planning for DVB-T and T-DAB services Practical considerations

Regional Information Meeting and Workshop related to the RRC-06 for the administrations of the Arab countries Damascus, Syria 16-18 August 2005. Planning for DVB-T and T-DAB services Practical considerations. Pham Nhu Hai Radiocommunication Bureau. Outline. What ’ s news in a digital world!

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Planning for DVB-T and T-DAB services Practical considerations

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  1. Regional Information Meeting and Workshop related to the RRC-06 for the administrations of the Arab countriesDamascus, Syria 16-18 August 2005 Planning for DVB-T and T-DAB services Practical considerations Pham Nhu Hai Radiocommunication Bureau

  2. Outline • What’s news in a digital world! • Policy objectives • Service considerations • System considerations • Planning considerations • Conclusions RRC information meeting and workshop - Damascus, Syria 16-18 August 2005

  3. Digital world! • DVB-T and T-DAB based on completely different techniques • Large number of carriers • Several programs bundled into multiplexes. Each multiplex • T-DAB: 6 to 8 programs • DVB-T: 2 to 4 PAL equivalent programs RRC information meeting and workshop - Damascus, Syria 16-18 August 2005

  4. Digital world!! Brick wall reception effect (4 to 1: 2dB) RRC information meeting and workshop - Damascus, Syria 16-18 August 2005

  5. Digital world!!! Reception modes • Fixed • Portable indoor • Portable outdoor • Mobile RRC information meeting and workshop - Damascus, Syria 16-18 August 2005

  6. Digital world!!!! Single Frequency networks (SFN) RRC information meeting and workshop - Damascus, Syria 16-18 August 2005

  7. Some policy considerations • How many? • Quality of service – High Definition • Same number of services throughout the country? or More in urban centres? • Same coverage between digital and analogue? • Simulcasting? How long? • Spectrum for other uses – digital dividend RRC information meeting and workshop - Damascus, Syria 16-18 August 2005

  8. Planning considerations • Minimise interference and disruption to analogue services • Minimise cost to viewers and broadcasters • Use of existing transmitting facilities • Consideration of existing receive antennas • Identify a minimum of channels RRC information meeting and workshop - Damascus, Syria 16-18 August 2005

  9. Service considerations • What reception mode? • Are future services likely to be delivered to portable and mobile receivers? • Trade-offs • Coverage • Number of Tx and frequencies used • Number of programs • Data capacity • Portable for main population • Fixed for outlying areas RRC information meeting and workshop - Damascus, Syria 16-18 August 2005

  10. Service considerations .. • T-DAB mobile or indoor? • Planning for indoor => mobile • Indoor requires more Tx or more powers compared to mobile • Same coverage as existing analogue • Number of services RRC information meeting and workshop - Damascus, Syria 16-18 August 2005

  11. Planning for mobile reception • Using allotments • Using assignments with higher ERP RRC information meeting and workshop - Damascus, Syria 16-18 August 2005

  12. DVB-T system variants? • Fixed reception • 64QAM and 2/3 code rate 1/8 guard interval • 16QAM and 2/3 code rate 1/8 guard interval • Mobile reception • 8K QPSK 2/3 rate and ¼ guard interval • 2K 16QAM ½ rate and ¼ guard interval • Use RPCs RRC information meeting and workshop - Damascus, Syria 16-18 August 2005

  13. C/N and Data rate vs code rate (source EBU) RRC information meeting and workshop - Damascus, Syria 16-18 August 2005

  14. C/N and Data rate vs guard interval(source EBU) RRC information meeting and workshop - Damascus, Syria 16-18 August 2005

  15. Spectrum considerations • 174-230 MHz • DVB-T and T-DAB • T-DAB only • DVB-T mobile • 470-862 MHz • DVB-T mobile in Band IV • Whole bands • Part of the bands RRC information meeting and workshop - Damascus, Syria 16-18 August 2005

  16. Acceptable channel • What is more benefit for administrations? • To determine acceptable channel • Submit with VHF or UHF RRC information meeting and workshop - Damascus, Syria 16-18 August 2005

  17. Network considerations.. • Multi Frequency Network (MFN) • Single Frequency Network (SFN) RRC information meeting and workshop - Damascus, Syria 16-18 August 2005

  18. Multi frequency network MFN • Each transmitter operates on a different frequency • Overlaps between transmitters possible • Regional or local programming • Ideal for conversion of existing analogue services RRC information meeting and workshop - Damascus, Syria 16-18 August 2005

  19. Single frequency network SFN • All transmitters operates on the same frequency and carry the same program • Ideal for national or large regional networks • Low power transmitters can be added if required • Most suited for mobile networks RRC information meeting and workshop - Damascus, Syria 16-18 August 2005

  20. Coverage issues • Percentage of locations • Within a 100 to 200 m square that predicted signal is exceeded • Percentage of time • Predicted signal exceeded during an average year RRC information meeting and workshop - Damascus, Syria 16-18 August 2005

  21. Same coverage as analogue • Limit of analogue reception? • Planned: grade 3 • Unwatchable: grade 1.5 or –7dB below • Suggested rule • Band III: 6-7 dB below analogue • Band IV, V: 10 dB • Conduct measurements RRC information meeting and workshop - Damascus, Syria 16-18 August 2005

  22. Calculate minimum median field strength • Minimum C/N • Receiver noise input power (receiver noise figure and noise bandwidth) • Effective antenna aperture (antenna gain) • Feeder loss • Minimum field strength • Man-made noise • Height loss • Building penetration loss • Location correction factor • Minimum median field strength RRC information meeting and workshop - Damascus, Syria 16-18 August 2005

  23. Minimum median field strength RRC-04 and IPG1 Reports (little program) RRC information meeting and workshop - Damascus, Syria 16-18 August 2005

  24. ERP level? • The advantage and disadvantage of increase the ERP in the draft plan? RRC information meeting and workshop - Damascus, Syria 16-18 August 2005

  25. Conversion? • The advantages of the case when a recorded analogue assignment is converted into digital? RRC information meeting and workshop - Damascus, Syria 16-18 August 2005

  26. Protection ratios ITU-R BT. 1368 DVB-T DVB-T ITU-R BS. 1660 T-DAB T-DAB 15 dB ITU-R BS. 1660 Analogue TV ITU-R BT. 1368 Analogue TV ITU-R T. 655 RRC information meeting and workshop - Damascus, Syria 16-18 August 2005

  27. Some protection ratios • Missing criteria • IPG working assumptions • Nominal figures (continuous) • Co-channel: +35 dB (41 dB) • Lower/upper adjacent: -9/-8 dB (-5 dB) • Image channel (n+10): -22dB (-18dB) RRC information meeting and workshop - Damascus, Syria 16-18 August 2005

  28. Protection ratios.. • Wanted digital – unwanted analogue • Co-channel: 3 dB • Lower/upper adjacent: -35/-38 dB • Image channel – not available RRC information meeting and workshop - Damascus, Syria 16-18 August 2005

  29. Protection ratios… • Wanted digital – unwanted digital • Co-channel: 20 dB • Lower/upper adjacent: -30dB • Image channel – not available RRC information meeting and workshop - Damascus, Syria 16-18 August 2005

  30. Protection ratios RRC information meeting and workshop - Damascus, Syria 16-18 August 2005

  31. One planning approach • Determine minimum median field strength • System variants • Reception mode • Determine ERP required to provide desired coverage • Propagation models • Tx site • Receive antenna RRC information meeting and workshop - Damascus, Syria 16-18 August 2005

  32. One planning approach.. • Calculate available protection ratio APR=W-U+AD+PD Where • W: wanted signal level (dBuV/m) • U: unwanted signal level (dBuV/m) • AD: antenna directivity (dB) • PD: polarisation discrimination (dB) • Use knowledge from existing analogue situation RRC information meeting and workshop - Damascus, Syria 16-18 August 2005

  33. One planning approach… • Determine available channels from comparing Required vs Available protection ratio • Eliminate other channels because of other possible interference mechanisms • Local oscillator • Image RRC information meeting and workshop - Damascus, Syria 16-18 August 2005

  34. Conclusions • Clear policy objectives • Consideration of existing transmitting and receive facilities • Use experience from the operation of analogue services • Carry out tests if necessary RRC information meeting and workshop - Damascus, Syria 16-18 August 2005

  35. Thanks for your attention RRC information meeting and workshop - Damascus, Syria 16-18 August 2005

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