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Regional Information Meeting and Workshop related to the Regional Information Meeting and Workshop related to the RRC-06 for the administrations of the Arab countriesRRC-06 for the administrations of the Arab countries
Damascus, Syria 16-18 August 2005Damascus, Syria 16-18 August 2005
Planning for DVB-T and T-DAB services
Practical considerations
Pham Nhu HaiRadiocommunication Bureau
RRC information meeting and workshop - Damascus, Syria 16-18 August 2005
OutlineOutline
What’s news in a digital world!Policy objectivesService considerationsSystem considerationsPlanning considerationsConclusions
RRC information meeting and workshop - Damascus, Syria 16-18 August 2005
Digital world!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
Digital world!!Digital world!!
Brick wall reception effect (4 to 1: 2dB)
RRC information meeting and workshop - Damascus, Syria 16-18 August 2005
Digital world!!!Digital world!!!
Reception modes– Fixed– Portable indoor– Portable outdoor–Mobile
RRC information meeting and workshop - Damascus, Syria 16-18 August 2005
Digital world!!!!Digital world!!!!
Single Frequency networks (SFN)
RRC information meeting and workshop - Damascus, Syria 16-18 August 2005
Some policy considerationsSome 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
Planning considerationsPlanning considerations
Minimise interference and disruption to analogue services
Minimise cost to viewers and broadcasters– Use of existing transmitting facilities– Consideration of existing receive
antennasIdentify a minimum of channels
RRC information meeting and workshop - Damascus, Syria 16-18 August 2005
Service considerationsService 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
Service considerations ..Service considerations ..
T-DAB mobile or indoor?– Planning for indoor => mobile– Indoor requires more Tx or more
powers compared to mobileSame coverage as existing analogueNumber of services
RRC information meeting and workshop - Damascus, Syria 16-18 August 2005
Planning for mobile receptionPlanning for mobile reception
Using allotmentsUsing assignments with higher ERP
RRC information meeting and workshop - Damascus, Syria 16-18 August 2005
DVB-T system variants?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
C/N and Data rate vs code rate C/N and Data rate vs code rate (source EBU)(source EBU)
RRC information meeting and workshop - Damascus, Syria 16-18 August 2005
C/N and Data rate vs guard intervalC/N and Data rate vs guard interval (source EBU)(source EBU)
RRC information meeting and workshop - Damascus, Syria 16-18 August 2005
Spectrum considerationsSpectrum 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
Acceptable channelAcceptable 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
Network considerations..Network considerations..
Multi Frequency Network (MFN)Single Frequency Network (SFN)
RRC information meeting and workshop - Damascus, Syria 16-18 August 2005
Multi frequency network MFNMulti frequency network MFN
Each transmitter operates on a different frequency
Overlaps between transmitters possible
Regional or local programmingIdeal for conversion of existing
analogue services
RRC information meeting and workshop - Damascus, Syria 16-18 August 2005
Single frequency network SFNSingle 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
Coverage issuesCoverage issues
Percentage of locations–Within a 100 to 200 m square that
predicted signal is exceededPercentage of time– Predicted signal exceeded during an
average year
RRC information meeting and workshop - Damascus, Syria 16-18 August 2005
Same coverage as analogueSame 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
Calculate minimum median field strengthCalculate 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
Minimum median field strengthMinimum median field strength
RRC-04 and IPG1 Reports (little program)
RRC information meeting and workshop - Damascus, Syria 16-18 August 2005
ERP level?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
Conversion?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
Protection ratiosProtection ratios
DVB-T
T-DAB
Analogue TV
DVB-T
T-DAB
Analogue TV
ITU-R BT. 1368
15 dBITU-R BS. 1660
ITU-R BS. 1660
ITU-R T. 655
ITU-R BT. 1368
RRC information meeting and workshop - Damascus, Syria 16-18 August 2005
Some protection ratiosSome 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
Protection ratios..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
Protection ratios…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
Protection ratiosProtection ratios
RRC information meeting and workshop - Damascus, Syria 16-18 August 2005
One planning approachOne 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
One planning approach..One planning approach..
Calculate available protection ratioAPR=W-U+AD+PDWhere• 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
One planning approach…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
ConclusionsConclusions
Clear policy objectivesConsideration of existing
transmitting and receive facilitiesUse experience from the operation of
analogue servicesCarry out tests if necessary
RRC information meeting and workshop - Damascus, Syria 16-18 August 2005
Thanks for your attentionThanks for your attention