Regional Information Meeting and Workshop related to the RRC-06 for the administrations of the Arab countries Damascus, Syria 16-18 August 2005 Planning.

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