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

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

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

RRC information meeting and workshop - Damascus, Syria August 2005 Digital world!!! Reception modes –Fixed –Portable indoor –Portable outdoor –Mobile

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

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

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

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

RRC information meeting and workshop - Damascus, Syria August 2005 Spectrum considerations MHz –DVB-T and T-DAB –T-DAB only –DVB-T mobile MHz –DVB-T mobile in Band IV –Whole bands –Part of the bands

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

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

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

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

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

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

RRC information meeting and workshop - Damascus, Syria August 2005 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 August 2005 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 August 2005 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 August 2005 Protection ratios

RRC information meeting and workshop - Damascus, Syria August 2005 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 August 2005 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 August 2005 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 August 2005 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 August 2005 Thanks for your attention