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DEVELOPMENT OF VHF AND UHF SPECTRUM OPTIMIZATION FOR DIGITAL SERVICES IN SELECTED STATES OF NIGERIA

by GBENGA-ILORI, ABIODUN OMOWUNMI, PhD


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7.2 Project Outcome 129
7.3 Recommendations 130
7.3.1. Recommendations to Government and Policy Makers 131
Appendix A: Transmitter Parameters from Nigerian Broadcasting Commission 133
Appendix B: Standard Deviation in Excel 135
Appendix C: GE 06 Data (Analogue and Digital Television) 137
Appendix D: Publications 152
References 202

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LIST OF FIGURES
Figure 1.1: Radio Frequency Spectrum 1
Figure 2.1 Plane-Earth Reference Model 14
Figure 2.2: Fresnel Zone 16
Figure 2.3 (a): Diffraction loss with positive h 17
Figure 2.3 (b): Diffraction loss with negative h 17
Figure 2.4: Bullington – Multiple Knife-edge approximation 19
Figure 2.5: Epstein-Peterson – Multiple Knife-Edge 20
Figure 2.6: Deygout - Multiple Knife-Edge Approximation 21
Figure 2.7: Diffraction by a rounded obstacle 21
Figure 2.8: Effect of vegetation 23
Figure 3.1 Locations of Field Strength Measurements 34
Figure 3.2 Actual Television Field Strength Measurement setup 35
Figure 3.3 Block Diagram for Measurement Experiment set-up 38
Figure 3.4: Deygout’s Construction 44
Figure 3.5: Modified Deygout Construction 44
Figure 3.6: Terrain Profile Separated by ∆ 47
Figure 3.7: Digitization Process 52
Figure 3.8: UBS 56
Figure 3.9: SILVERBIRD 56
Figure 3.10: NTA Channel 10 Lagos 56
Figure 3.11: NTA Channel 5 Lagos 57
Figure 3.12: MITV 57
Figure 3.13: MINAJ 57
Figure 3.14: LTV 58
Figure 3.15: Galaxy 58
Figure 3.16: DBN 58
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Figure 3.17: Channels Television 59
Figure 3.18: AIT 59
Figure 3.19: Kwara State Television 59
Figure 3.20: Kwara State Television – Ilorin city and environs 60
Figure 3.21: NTA Patigi 60
Figure 3.22: NTA Ilorin 60
Figure 3.23: NTA Ilorin – Ilorin City and Environs 61
Figure 3.24: NTA Oshogbo 61
Figure 3.25: NTA Oshogbo - Oshogbo and environs 61
Figure 3.26: OSBC 62
Figure 3.27: OSBC – Oshogbo and environs 62
Figure 3.28: NTA Ile-Ife 62
Figure 3.29: NTA Akure 63
Figure 3.30: NTA Akure – Akure City 63
Figure 3.31: NTA Okitipupa 63
Figure 3.32: OSRC 64
Figure 3.33: OSRC – Akure 64
Figure 3.34: NTA Channel 12 Abeokuta 64
Figure 3.35: NTA Channel 12 Abeokuta – Abeokuta 65
Figure 3.36: NTA Ijebu-Ode 65
Figure 3.37: NTA Imeko 65
Figure 3.38: OGTV 66
Figure 3.39: OGTV – Abeokuta 66
Figure 3.40: BCOS 66
Figure 3.41: Galaxy, Ibadan 67
Figure 3.42: NTA Ibadan 67
Figure 3.43: NTA Ogbomosho 67
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Figure 3.44: NTA Ogbomosho – Ogbomosho 68
Figure 3.45: NTA Oyo 68
Figure 3.46: NTA Saki 68
Figure 3.47: Broadcasting Service of Ekiti 69
Figure 3.48: Broadcasting Service of Ekiti – Ado-Ekiti 69
Figure 3.49: NTA Ado-Ekiti 69
Figure 3.50: NTA Ado-Ekiti – Ado-Ekiti city 70
Figure 3.51: KSTV 70
Figure 3.52: KSTV – Lokoja 70
Figure 3.53: NTA Kaaba 71
Figure 3.54: NTA Lokoja 71
Figure 3.55: NTA Lokoja – Lokoja city 71
Figure 3.56: Prediction Errors for all the considered states 72
Figure 3.57: Prediction Errors for the Urban/Suburban Areas 73
Figure 3.58: Prediction Errors for the Rural Areas 74
Figure 3.59: Clutter Effect Lagos-ROUTE 1 76
Figure 3.60: Clutter Effect Lagos -ROUTE 2 76
Figure 3.61: Clutter Effect Oshogbo-ROUTE 1 76
Figure 3.62: Clutter Effect Oshogbo -ROUTE 2 77
Figure 4.1: Analogue Television Interference-Limited Coverage .
Map for Selected States 85

Figure 4.2: Digital Television (Simulcast) Interference-Limited Coverage Map
for Selected States 91
Figure 4.3: Digital Television (Switch-off) Interference-Limited Coverage Map
for Selected States 94
Figure 5.1: Present number of analogue terrestrial television stations in Nigeria 100
Figure 5.2: Gain of statistical multiplexing 107

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LIST OF TABLES
Table 3.1: Comparison of Measured and Predicted Field Strength 54
Table 3.2: Result for Urban and Suburban Areas 73
Table 3.3: Result for Rural Areas 74
Table 4.1: Minimum Field Strength for Analogue Television Planning 80
Table 4.2: Minimum Field Strength for Digital Television Planning 81
Table 4.3: Result of Spectrum Used by Each State with Analogue Television 86
Table 4.4: Digital Television Protection Ratio 87
Table 4.5: Result of Spectrum Used by Each State with Digital Television (Simulcast) 92
Table 4.6: Result of Spectrum Used by Each State with Digital Television (Switch-Off) 95
Table 5.1: Analogue Television Spectrum Utilization Efficiency 101
Table 5.2: Predicted Digital Television Spectrum Utilization Efficiency 102
Table 5.3: Number of Programs with Fixed Reception in the Present 109
Table 5.4: Number of Programs with Fixed Reception in the future 110
Table 6.1: Television Spectrum in Selected States 114
Table 6.2: Compatibility Level of Services Competing for Digital Dividend 117
Table 6.3: Revenue Potential 120
Table 6.4: Summary of Social Evaluation 125
Table 6.5: Proposed Use of Digital Dividend 126

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GLOSSARY OF TERMS
ATV Analogue Television
BBC British Broadcasting Corporation
DEM Digital Elevation Model
DTV Digital Television
DVB-H Digital Video Broadcasting – Handheld
DVB-T Digital Video Broadcasting – Terrestrial
FWA Fixed Wireless Access
GE 06 Geneva 2006
GIS Geographic Information System
GPRS General Packet Radio Service
GPS Global Positioning System
GSM Global System for Mobile Communications
HDTV High Definition Television
ICT Information Communication Technology
IRT Institut für Rundfunktechnik
ITM Irregular Terrain Model
ITU-R International Telecommunication Union – Radio communication Sector
MBMS Multimedia Broadcast Multicast Service
MFN Multi Frequency Network
MPEG Moving Picture Expert Group
NTA Nigerian Television Authority
PR Protection Ratio
QAM Quadrature Amplitude Modulation
SAR Synthetic Aperture Radar

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SDTV
SFN
SRTM
TIREM
UMTS
USB
WiMAX
3G

Standard Definition Television
Single Frequency Network
Shuttle Radar Topography Mission
Terrain Integrated Rough Earth Model
Universal Mobile Telecommunication System
Universal Serial Bus
Worldwide Interoperability for Microwave Access
Third Generations

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CHAPTER 1

INTRODUCTION

1.1 BACKGROUND TO THE STUDY

The desire to have reliable means of communication anywhere and at anytime has led to new
innovations in digital communication technologies. Some of these new digital technologies
include mobile television and enhanced mobile phone services, digital television, wireless
broadband, security and surveillance, environmental monitoring, and distance learning. All of
these require the use of part of the electromagnetic spectrum for communication purposes.
These new developments in digital communication technologies have increased the pressure
on the part of electromagnetic spectrum known as radio frequency spectrum.

The electromagnetic spectrum is the range of all possible frequencies of electromagnetic
radiation. The electromagnetic spectrum is divided into sections based on wavelength and it
extends from frequencies used for electric power at the long wavelength to frequencies for
gamma radiation at the short wavelength, [1]. The frequency ranging from 3 Hz to 300 GHz
is generally referred to as the radio frequency spectrum, [2]. This part of the spectrum is
further divided into frequency bands as shown in figure 1.1 below.

VLF LF MF HF VHF UHF SHF EHF
3 30 300 3 30 300 3 30
300

kHz MHz GHz

Figure 1.1: Radio Frequency Spectrum.

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Most communication technologies use the radio spectrum however, the Ultra High Frequency
(UHF) is particularly attractive to newer technologies because lower frequencies are very
prone to interference and higher frequencies have problems of limited signal range because of
the difficulty signals have in penetrating buildings. For these reasons, the UHF band is highly
competitive. The radio spectrum is a natural resource which can be reused and can only
accommodate a limited number of simultaneous users. This competition can lead to
congestion of the band and this can result in harmful interference that can degrade signals or
interrupt communication services if the spectrum is left unplanned.

Before the existence of the new digital services, the Very High Frequency (VHF) and Ultra
High Frequency ( UHF) bands were primarily used for terrestrial analogue television
broadcasting services. The agreed bandwidth of an analogue television channel is 8MHz in
the VHF and UHF frequency bands III, IV and V. There have been questions on how much
spectrum is actually needed by television broadcasting services and how much has been
allocated in the past when there was no competition for the UHF spectrum. Some spectrum
managers are of the opinion that analogue television services has been allocated more
spectrum than needed and that with careful optimization and re-planning of the frequency
bands, some spectrum can be released for new services, [4].

Asides the issue of spectrum resource allocation, analogue television’s use of the spectrum is
inefficient compared to newer terrestrial digital television technology. Digital television is
the sending and receiving of moving images and sound by discrete (digital) signals, in
contrast to the analogue signals used by analogue television, [5]. Due to compression
technology employed in digital television broadcasting, signals can be compressed to allow
more information to be aired using less spectrum space compared to analogue television. The
use of less spectrum means that some spectrum can be freed up and made available to new
digital services.
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The efficient use of the spectrum by digital television has led to the worldwide campaign on
transition from analogue to digital television broadcasting television by spectrum regulators.
In Nigeria, a set date of 17th June, 2012 has been given by the Federal Government for the
transition to digital television, [6]. The transition to digital in Nigeria, as in most countries,
would not be a sudden switch off of analogue television but there would likely be a period of
simulcast when analogue and new digital television services would co-exist. Many countries
that have commenced digital television broadcasting services started with a period of
simulcast transmission of both types of signals. The length of the simulcast period is
dependent on a number of factors. Cost, to both broadcasters and viewers, is a major
determinant of the length of the simulcast period. In order to receive terrestrial digital
television, viewers need either a digital television set or convert signals. The cost of digital
television set or the set-up box will not encourage entire and immediate switch over to digital
television especially for a developing country like Nigeria.

For the reasons above, there is the need to optimize the use of spectrum by present analogue
television services and estimate to the amount of spectrum that can be released for new
digital services during simulcast transmission of both signals and also after switchover to
digital. The freed-up spectrum is referred to as the ‘digital dividend’ and it is defined as the
spectrum over and above the frequencies which are required to support existing analogue
broadcasting services in a fully digital environment, [7].

The size of digital dividend has been estimated in some developed countries, [7], and there is
also the need to assess or predict the size of this future digital dividend in Nigeria too. This
will help administrators and regulators to use and manage the released spectrum efficiently
since there are many competing services for its use. Also, there is need to estimating the size
of this future digital dividend ahead of time because if the VHF and UHF bands are not
available on time for these new digital services, other spectrum would have to be used and
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