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NETWORK CONFIGURATIONS

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BR Seminar 18-19 September 2003

Jean-Jacques GUITOT

ANFR - DPSAI – Dépt Planification – Etudes prospectives

Guitot@anfr.fr

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Which Reception Mode?

Hand portable?

Portable outdoor or indoor?

Mobile?

Fixed?HDTV ou portable?

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Minimum required field strength Illustration of scheme of different receiving conditions for DVB-T

DVB-T Transmitter

Rice channel

Fixed reception

---------- 10m

Location correction

factor = 9dB

(C/N)f

Portable reception

Height loss dB

---------- 10m

Penetration loss dB

---------- 1,5m

Rayleigh channel

(C/N)p

Mobile reception

Location Correction

factor = 9.1 or 13 dB---------- 1,5m

---------- 10m

Height loss dB

(C/N)m

Rayleigh channel

Location Correction

factor = 4dB

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Minimum required field strength

Minimum median equivalent field strength for a location probability of 95% of locations

• +4dB for 99% of locations• + 11 to 15 dB for indoor coverage

DVB-T Mode QPSK ½ QPSK 2/3 16 QAM ½ 16 QAM 2/3 64 QAM ½ 64 QAM 2/3C/N {dB} 8 10.5 14 16.5 18 22

Frequency {MHz} Band III200 MHz

Height loss {dB} 10Emed {dBµV/m} 53 55.5 59 61.5 63 67

Frequency {MHz} Band IV500 MHz

Height loss {dB} 12Emed {dBµV/m} 60 62.5 66 68.5 70 74

Frequency {MHz} Band V800 MHz

Height loss {dB} 12Emed {dBµV/m} 64 66.5 70 72.5 74 78

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Illustration of services(source Jorn Andersen DK)

Fixed antenna, 70%, 17200 sqkm

Fixed antenna, 95%, 12100 sqkm

Portable antenna, outdoor, 70%, 4540 sqkm

Portable antenna, indoor, 70%, 2460 sqkm

Portable antenna, outdoor, 95%, 2830 sqkm

Portable antenna, indoor, 95%, 1020 sqkm

Transmitter data: 25 kW, 300 m, 500 MHz

Modulation: 64QAM, Code rate 2/3

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• Size of service area

• Shape of service area

• Percentage of Location probability

Which coverage?

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• OFDM, VSB

• If OFDM : 2 k, 8K

• System variants– Hierarchical , non-hierarchical modulation– QPSK, 16 QAM, 64 QAM– Code rate– bitrate

Which DTTB Systems?

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1. MFN : Multi Frequency Network• different frequencies assigned to each site• Coverage provided by a transmitter

2. SFN : Single Frequency Network• The same frequency assigned to each site

• Synchronised• Same content

• Self interference to be taken into account for portable and mobile (size limited)

• Every transmitter contribute to provide the coverage and cannot operate independently

Which Network Configuration?

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• Network Configuration– MFN, SFN

• With technical parameters to be taken into account– Antenna height– Antenna directivity– E.r.p.– Distance between sites for MFN or SFN

• Re-use of existing sites;• Re-use of existing sites and creation of sites• Complete creation of sites

For providing a service coverage

Which choice of network?

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DTTB ServiceReception mode

Reception Coverage (% location probability)

System; 2K or 8 K,

VariantHierarchical; non-hierarchical

Network configuration

imply

Optimisation of network choice

Process for a choice of network

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Network Configurations in Planning

• Configuration modes– MFN – SFN With technical parameters

• Antenna heights• Antenna patterns• E.R.P.

– Distance between sitesand /or

– Width and shape of service area

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Configurations modes in Planning

• MFN : • SFN : implementation by

– Few high power stations– More stations but lower radiated power – Main stations complemented by gap-filler (low power

stations)

• Mixed MFN and SFN– In a same country some coverage are provided by

MFN and by SFN– In adjacent countries, one is implementing MFN type,

the other SFN type

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MFN (and gap-filler SFN)

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SFN

       synchronous signal        same RF channel         same content

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• Guard interval– has a major implication on the topology of

SFN implementation– Duration governs the maximum echoes delay

admissible by the system : maximum possible distance between co-channel transmitters

• More or less Large SFN

SFN parameters

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OFDM signal parameters

 

That for non-directive antenna

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SFN Reference structure (Open or Closed)

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Width of the coverage area

Separation distance

Area to be covered Transmitter

Unwanted transmitter Wanted transmitter

MFN Reference structure

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• Take into account requirements to describe configuration networks

• Use technical bases for calculation• Transmitter distances between co-channel for

MFN• Separation distances between SFN

Frequency Planning

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Thank you for your attention…