UNIVERSITY OF NAIROBI

Transcription

1 UNIVERSITY OF NAIROBI DEPARTMENT OF ELECTRICAL AND INFORMATION ENGINEERING CASE STUDY ON RADIO FREQUENCY SPECTRUM MANAGEMENT IN KENYA PROJECT NO: PRJ69 BY CHESANG K. ANTHONY REG NO: F17/1796/2006 SUPERVISOR: Dr. CYRUS WEKESA EXAMINER: Dr. V.K ODUOL THIS PROJECT REPORT IS SUBMITED IN PARTIAL FULFILMENT OF THE REQUIREMENT FOR THE AWARD OF A BACHELOR OF SCIENCE DEGREE IN ELECTRICAL AND ELECTRONIC ENGINEERING. 18 TH MAY 2011

2 DEDICATION To my family i

3 ACKNOWLEDGEMENT My heartfelt gratitude first goes to Dr. Cyrus Wekesa Snr. Lecturer University of Nairobi, who supervised this project; I am impressed by his guidance and simplicity of suggestions, which really contributed to the success of this project work. I would like to thank my lecturers in the Department of Electrical and Information Engineering for the enriched knowledge they imparted on me for the past five years. More thanks to Eng. L.K Boruet, Mr. Kibe and Eng. Kandagor of CCK, for the helpful information they provided me with regards to my project. Thanks to all my classmates for their support during the development of this project. ii

4 DECLARATION Except where indicated and acknowledged, I certify that the information presented in this report is my original effort and has not been presented before for a degree award in this or any other university to the best of my knowledge... CHESANG K. ANTHONY F17/1796/2006 This report has been submitted to the Dept. of Electrical and Information Engineering, University of Nairobi with my approval as a supervisor: Dr. CIRUS WEKESA Date: 18 th May, 2011 iii

5 TABLE OF CONTENTS Page ACKNOWLEDGEMENT... ii 1 CHAPTER 1: INTRODUCTION Problem Definition Objectives Report Organization CHAPTER 2: LITERATURE REVIEW Radio frequency spectrum Electromagnetic wave propagation Line-of sight propagation Ground wave propagation Sky wave propagation Nomenclature of RF bands CHAPTER 3: SPECTRUM MANAGEMENT IN GENERAL Introduction Objectives of Spectrum Management Radio Spectrum users International Telecommunication Union (ITU) ITU Radio Regulations ITU R Recommendations World Radio Conferences (WRCs) Regional Regulatory Conferences (RRCs) ITU Regions Spectrum planning Spectrum engineering analysis and standards Prediction of radio wave propagation Protection ratio Transmitter equipment specification Interference analysis Necessary radio frequency bandwidth iv

6 3.6.6 Receiver equipment parameters CHAPTER 4: SPECTRUM MANAGEMENT IN KENYA Introduction National Table of Frequency Allocation Mechanisms for dividing up access to spectrum SPECTRUM PRICING Spectrum pricing requirements Annual Current frequency spectrum fee schedule in Kenya SPECTRUM AUTHORIZATION Parameters notified to ITU-R after assigning spectrum to a user Administrative Methods of assigning spectrum Market Methods Current spectrum utilization in Kenya [source CCK database] Unlicensed Spectrum Spectrum monitoring and inspection Spectrum Monitoring Technology Monitoring Equipment Designing Spectrum Monitoring Systems Spectrum monitoring capabilities in Kenya Radio spectrum management and monitoring system layout in Kenya CHAPTER FIVE: IMPACT OF INTRODUCTION OF DIGITAL BROADCSTING ON SPECTUM UTILIZATION IN KENYA Introduction Current Broadcasting Situation Analog FM broadcasting analysis Analogue television broadcasting analysis Digital Terrestrial Television DVB-T2 analysis Benefits of Digital Broadcasting Digital Signal distribution CHAPTER 6: CONCLUSIONS RECOMMENDATIONS Conclusions and Recommendations v

7 7 APPENDIX vi

8 List of tables Table 1.1 nomenclatures of RF bands... 5 Table Table 3.4 Broadcast stations fee per transmitter Table 4.5 of bands for broadcasting Services and the planned digital service Table 5.5 Comparison of parameters between DVB-T and DVB-T Table 6.5 Number of television programmes per multiplex (8 MHz channel) for fixed reception with DVB-T, 16-QAM,code rate2/3,fft 8K,Guard interval 1/4 and DVB-T2 with16-qam,code rate 5/6, FFT 16K,Guard interval 1/8 [6] List of figures Figure 1.1 electromagnetic wave... 2 Figure 2.1 Huygens Principle for (a) a plane wave and (b) a spherical wave... 3 Figure 3.1 Line-of sight propagation... 3 Figure 4.1. Ground wave propagation... 3 Figure 5.1 Sky wave propagation... 4 Figure 6.3 ITU Regions... 9 Figure 7.4 monitoring antenna with vertical dipole Direction finding antennas Figure 8.4mobile monitoring station Figure 9.4Image of triangulation location of a transmitter page vii

9 LIST OF ABBREVIATIONS CCK ICT ITU RF ELF SLF ULF VLF LF MF HF VHF UHF SHF EHF db dbµv/m BW TRXs MHz GHz KHz Hz KShs. Communications Commission of Kenya Information Communication Technology International Telecommunication Union Radio Frequency Extremely Low Frequency Super Low Frequency Ultra Low Frequency Very Low Frequency Low Frequency Medium Frequency High Frequency Very High Frequency Ultra High Frequency Super High Frequency extremely high frequency decibel decibel micro-volts per meter Bandwidth Transmitters Megahertz Gigahertz Kilohertz Hertz Kenya shillings viii

10 ISM RRC T-DAB DVB-T HD-720P HD-1080i MPEG AVC OFDM SFN MFN WRC Industrial Scientific Medical Radio Regulations Conference Terrestrial Digital Audio Broadcasting Terrestrial Digital Video Broadcasting High-definition progressively-scanned TV format of 1280 x 720 pixels High-definition interlaced TV format of 1920 x 1080 pixels Moving Picture Expert Group Advanced Video Coding Orthogonal Frequency Division Multiplexing Single Frequency Network Multi-Frequency Network World Radiocommunication Conference ix

11 ABSTRACT Radio frequency spectrum is a natural resource that can be used to increase the efficiency and productivity of a nation. It is used to provide a wide variety of radio-communication services including personal and corporate communications, radio navigation, aeronautical and maritime radio, broadcasting, public safety and distress operations, radio location and amateur radio. Frequency spectrum management tasks call for planning and coordination of frequency spectrum usage at international and national levels; allocating and assigning spectrum nationally, monitoring, inspection and resolving radio frequency interference. In this project, various spectrum management activities carried out in Kenya to achieve efficient and effective spectrum utilization are described. These activities cover the spectrum planning, pricing, authorization, monitoring and inspection. The impact of introduction of digital broadcasting in Kenya on spectrum utilization is also analyzed. x

12 1.1 Problem Definition 1 CHAPTER 1: INTRODUCTION Frequency spectrum management is an ever increasing challenge due to ever increasing number of users of the existing radio services and the number of new radio based services. Radio frequency spectrum is a limited natural resource. Anytime or anyplace a portion of it is used precludes the use of that portion at that time or place. Without spectrum management, the development of the ICT will be hindered resulting into economic impact to the country. Only well organized spectrum management maximizes the benefits of its use. Spectrum must be managed centrally to ensure consistent and logical approach to all frequencies. Radio frequency unlike other resources; Cannot be polluted, can only be subjected to harmful interference of which can be purified for reuse once the source of this interference is eliminated Cannot be depleted through use 1.2 Objectives Read and understand spectrum management in general To carry out a case study on frequency spectrum management in Kenya Study the impact of introduction of digital broadcasting in Kenya on spectrum utilization 1.3 Report Organization Chapter 2 covers a review on literature about radio frequency spectrum. The author then goes on to develop a theoretical framework on spectrum management in general. Chapter 4 covers spectrum management in Kenya. Chapter 5 analyses the impact of introduction of digital broadcasting in Kenya on frequency utilization, then finally a conclusion and recommendations documented. 1

13 2 CHAPTER 2: LITERATURE REVIEW 2.1 Radio frequency spectrum. Radio frequency spectrum is a subset of the electromagnetic waves that is between 3 KHz to 300 GHz that is used for wireless communications. Electromagnetic wave comprises electric and magnetic fields propagated by oscillating at perpendicular planes to each other at a velocity of m/s in vacuum. As shown in fig 1.1 Figure 1.1 electromagnetic wave The velocity of propagation is given by expression c=f λ where c= m/s, f is the frequency in Hz and λ is the wavelength in meters. According to the propagation characteristic, spectrum using higher frequencies reaches shorter distances but has a larger carrying capacity while spectrum using lower frequencies reaches longer distances but has a lower carrying capacity. This characteristic limits the application of spectrum in various services. [1] 2.2 Electromagnetic wave propagation Electromagnetic waves propagate as a series of expanding wave fronts. This can be best understood by applying Huygens Principle of wave theory. This principle states that each element of the expanding wave fronts act as a source of radiation sending out a secondary radiation from all elements of the original wave add up to form a new wave front,each element of which re-radiates in turn. This illustrated in the figure 1.2 [1] 2

14 Figure 2.1 Huygens Principle for (a) a plane wave and (b) a spherical wave Line-of sight propagation Transmitting and receiving antennae are in sight of each other Figure 3.1 Line-of sight propagation Ground wave propagation Signals follow curvature of the earth. Can propagate considerable distances. Frequencies up to 2 MHz Figure 4.1. Ground wave propagation 3

15 2.2.3 Sky wave propagation Signal reflected from ionized layer of atmosphere back to earth. Signal can travel a number of hops, back and forth between ionosphere and earth s. surface Cover large distances. Figure 5.1 Sky wave propagation 4

16 2.3 Nomenclature of RF bands The table 1.1 shows the nomenclature of RF bands Table 1.1 nomenclatures of RF bands Band Symbols Frequency Range Wavelength Range Example of uses Number 1 ELF 3 to 30 Hz 10,000 to 100,000 km deeply-submerged submarine communication 2 SLF 30 to 300 Hz 1000 to 10,000 km submarine communication, ac power grids 3 ULF 300 to 3 khz 100 to 1000 km earth mode communication 4 VLF 3 to 30 khz 10 to 100 km near-surface submarine communication, 5 LF 30 to 300 khz 1 to 10 km AM broadcasting, aircraft beacons 6 MF 300 to 3000 khz 100 to 1000 m AM broadcasting, aircraft beacons 7 HF 3 to 30 MHz 10 to 100 m Sky-wave long range radio communication: shortwave broadcasting, military, maritime, diplomatic, amateur two-way radio 8 VHF 30 to 300 MHz 1 to 10 m FM radio broadcast, television broadcast, DVB-T 9 UHF 300 to 3000 MHz 10 to 100 cm television broadcast, GPS, mobile phone communication (GSM, UMTS, 3G, HSDPA), WLAN (Wi-Fi b/g/n), Bluetooth 10 SHF 3 to 30 GHz 1 to 10 cm DBS satellite television broadcasting, WLAN (Wi-Fi a/n), microwave relays, WiMAX, radars 11 EHF 30 to 300 GHz 1 to 10 mm microwave relays, intersatellite links, high resolution radar, directed-energy weapon, Security screening 5

17 3 CHAPTER 3: SPECTRUM MANAGEMENT IN GENERAL 3.1 Introduction Frequency spectrum management refers to various administrative and technical procedures that are intended to ensure the operation of radio stations of different radiocommunication services at any given time without causing or receiving harmful interference. It takes place at two levels: national and international level. Spectrum management involves planning, allocating, assigning, monitoring and inspection of spectrum 3.2 Objectives of Spectrum Management To ensure rational, equitable, efficient and economic use of the radio frequency spectrum by all radio communication services. To maximizes spectrum use by allowing maximum number of users, while keeping interference and congestion manageable. To ensure spectrum is utilized in a manner that meets the country s goals. 3.3 Radio Spectrum users Civil Telecommunications (Fixed, Mobile & Satellite). Military communications and radars. Aeronautical communications and radars. Maritime communications and radars. Broadcasting. Space Science Services. Radio Astronomy. Earth Exploration Satellites. Amateur Radio. Industrial, Scientific and Medical applications. 6

18 3.4 International Telecommunication Union (ITU). Propagation of radio waves travels across national borders and therefore effective spectrum management requires regulation starting right from international level. International Telecommunication Union (ITU) is a specialized agency of the United Nations which is responsible for regulation of spectrum use at the international level and in particular, its Radiocommunication Sector (ITU-R). Its rules are written by its member states and administered by the ITU s Radiocommunication Bureau (BR) and the conformity with the rules supported by regulations at the national level. ITU is based in Geneva, Switzerland, and its membership includes 192 Member States and around 700 Sector Members and Associates. Kenya became a member of ITU on In summary, the functions of ITU-R include: Organize worldwide and regional exhibitions, forums and conferences on radio spectrum management. Coordinate the shared global use of the radio spectrum. ensure rational, equitable, efficient and economic use of the radio frequency spectrum by all radio communication services study and adopt recommendations on radio communication matters ITU Radio Regulations The Radio Regulations are the international treaty governing the use of the radio-frequency spectrum. They provide the overall global framework for spectrum use, including the International Frequency Allocation Table, which allocates spectrum to broad categories of service such as fixed, mobile, broadcasting or radionavigation. The Radio Regulations are agreed at World Radio Conferences and Member States who do not abide by the Regulations will not be protected from any interference for the service concerned.[2] 7

19 3.4.2 ITU R Recommendations ITU-R Recommendations provide guidance on the use of radio spectrum by specific services and apparatus, including technical criteria for planning coverage and avoiding interference. These Recommendations do not have the same legal status as the Radio Regulations - they are intended to be advisory rather than mandatory. However, most national administrations take them sufficiently serious that they are widely acknowledged and implemented in practice. Use of these recommendations ensures that the same methods are used in spectrum engineering practice (including terminologies) and thus easier coordination of frequency across various countries World Radio Conferences (WRCs) WRCs are held every two to three years. Their purpose is to review and revise the radio regulations. Revisions are made on the basis of an agenda determined by the ITU Council, which takes into account recommendations made by previous WRCs. [2] Regional Regulatory Conferences (RRCs) RRCs are conferences of either an ITU Region or a group of countries with a mandate to develop an agreement concerning a particular radiocommunication service or frequency band. RRCs cannot modify the Radio Regulations unless subsequently approved by a WRC. Final acts of RRC are only binding on those countries that are party to the agreement. [2] 8

20 3.4.5 ITU Regions The International Telecommunication Union (ITU) divides the world into three regions for the purposes of efficient management of the global radio spectrum. Each region has its own set of frequency allocations. Region 1 comprises Europe, Africa, Middle East, Iraq, former Soviet Union and Mongolia. Region 2 covers the America, Greenland and some of the eastern Pacific Islands. Region 3 comprises Asia, east of and including Iran Figure 6.3 ITU Regions 9

21 3.5 Spectrum planning Spectrum Planning is carried out to ensure efficient and effective use of the spectrum resource to the fullest extent possible. At the international level, agreements are formed amongst nations on spectrum use and technical specifications to aid coordination of services globally. Planning is usually undertaken for long-term, medium-term and short-term timeframes. Long-term planning (10 to 20 years) is required to foresee spectrum requirements far into the future. Medium-term planning (5 to 10 years) is carried out to determine what changes should be made on spectrum policies to meet the changing needs of users and evolving technologies. Short-term planning (below 5 years) is carried out to make changes to spectrum policies and adjust earlier decisions. Forecasting future spectrum use is very important if future spectrum needs are to be met. This is normally done through projections on historical growth through monitoring of new technologies noting their spectrum requirements and consulting with the spectrum users as they are usually in the best position to forecast growth in their sector. It is also important to know the current uses of spectrum as a baseline for future planning. This can be ascertained from existing records of frequency use across the entire radio spectrum. Frequency registers and computer-automated tools are also used to aid planning. 3.6 Spectrum engineering analysis and standards In order to ensure electromagnetic compatibility among various services and stations, good and sound engineering practices are essential. The following factors and standards are considered Prediction of radio wave propagation Propagation loss is a key parameter in determination of the coverage area of the radio systems and the extent of potential of harmful interference. In general, Basic transmission loss between two isotropic antennas due to the dispersion of energy which takes place as the wave travels away from the transmitter is given by the equation: Ao = -20log10 [1.1] (Ao= free-space attenuation (db), λ=wavelength in kilometers, d=distance in kilometers) 10

22 3.6.2 Protection ratio Protection ratio is the minimum value of the wanted-to-unwanted signal ratio, usually expressed in db or in dbµv/m, at the receiver input, needed to achieve a satisfactory reception quality of the wanted signal at the receiver output. This is defined in various ITU recommendations to ensure electromagnetic compatibility among various services. For example the protection ratio for vision carrier from the unwanted sound carriers in TV broadcasting is -9dB, and the minimum field strength to be protected in TV Bands IV and V is 65 dbµv/m and 70 dbµv/m [2] Transmitter equipment specification Spectrum use state transmitter equipment technical standard requirements for the efficient use of a specified frequency band. These standards are used in testing and certification of the transmitter equipment. These include: Tolerance This is the maximum permissible departure from the center frequency of the frequency band occupied by an emission from the assigned frequency. It is expressed in Hz. Deviation must be small, ideally 1% of channel bandwidth or less. Table of tolerance of various radiocommunication services in various frequency bands is given in appendix [B] Spurious emissions These are unwanted emissions of transmitters. They are emissions outside the necessary bandwidth and which the level may be reduced without affecting the corresponding transmission of information. Spurious emissions include; harmonic emissions Parasitic emission Intermodulation product emission frequency conversion products 11

23 generally spurious emission limit must be: log (P), or 70 dbc, whichever is less stringent. Where P=carrier power [ITU] Spurious emissions of some selected services is given in appendix [A] Interference analysis The radio regulations define interference as: The effect of unwanted energy due to one or a combination of emissions, radiations or inductions upon reception in a radiocommunication system, manifested by any performance degradation, misinterpretation or loss of information which could be extracted in the absence of such unwanted energy [3] Interference occurs as a result of; Harmonics, spurious and parasitic emissions, Co-channel interference, Adjacent channel interference Receiver desensitization, Intermodulation products Necessary radio frequency bandwidth This is the width of the frequency band which is just sufficient to ensure the transmission of information at the rate and with the quality required under specified conditions. The Radio Regulation requires that RF bandwidth of emissions to be kept as small as possible to ensure maximum frequency utilization. The ITU-R SM. 853 gives the various formulas for determining the necessary RF emission bandwidths of various services. For instance the necessary RF bandwidth BW for a single channel analogue FM system is BW =2M+2D where M is the maximum modulating frequency and D is the peak frequency deviation.[3] 12

24 3.6.6 Receiver equipment parameters Receiver sensitivity. Receiver sensitivity is the lowest modulated carrier signal strength required to give minimum signal to noise and distortion ratio after detection. This is measured at 12dB SINAD, in the following relationship. (signal+noise+distortion)/(noise+distortion)=12db Digital receivers suffer from the same effects as analogue receivers, but have some capacity to reconstitute the digital signal, making effects less noticeable. [3] Receiver selectivity. This is the measure of receiver ability to receive a modulated signal in the presence of modulated signals which differ in frequency from the standard input signal frequency by a spacing of one channel. Receiver with a high selectivity can effectively ignore the presence of out-of-band signals [3] Receiver desensitization This is the ability of a receiver to operate in the presence of a much higher power signal level for example when a transmitter is operated close to a receiver, the relatively high signal strength from the transmitter can overload the receiver input circuits, and reduce the sensitivity of the receiver to wanted signals, even though the transmitter is on another frequency. In frequencies above 30MHZ, the minimum adjacent selectivity and desensitization should be 70dB or better measured at 12 SINAD [3] 13

25 4 CHAPTER 4: SPECTRUM MANAGEMENT IN KENYA 4.1 Introduction Frequency Spectrum management in Kenya is carried out by communications commission of Kenya (CCK). Functions of communications commission of Kenya Establishment of national table of frequency allocations Long-term spectrum management policy and planning to determine and periodically update the existing and future requirements for the various radio communications services. Assignment of frequencies ensuring electromagnetic compatibility of all proposed or requested assignments with regard to existing assignments on a national or international basis. Protect the country's radio communication systems from potential interference from another country's assignments. Record-keeping of frequency assignments for effective national and international coordination, licensing and enforcement activities, policy formulation, investigations on interference and resolution, and financial considerations. Carry out radio spectrum monitoring and inspection. 4.2 National Table of Frequency Allocation Kenya has developed its own table of frequency allocation within the framework of the ITU's Radio Regulations. This table allocates a given frequency spectrum band to a given service for example fixed, mobile maritime or aeronautical. This is one of the first steps in long and medium-term planning. Once a national frequency allocation table has been developed, further sub-allocations of use are often made in order to group similar technologies and similar users in a given frequency band. Greater spectrum efficiencies are obtained when uses with similar technical parameters share the same frequency band, for instance lumping high power applications with other high power applications. 14

26 4.3 Mechanisms for dividing up access to spectrum. Frequency spectrum is a limited natural resource. There is a higher demand than supply and therefore accommodating many users calls for frequency band sharing. The following are various techniques employed to achieve frequency band sharing. Geographical sharing In this case a user is given a license to transmit on part of the country. A different user is given a license to use the same frequencies in a different part of the country. The two users needs to be sufficiently far apart so that they will not interfere with each other on the boundary of their operations. In practice, this implies either a guard zone between coverage areas or some restrictions on emissions near the boundary. Band sharing In this case, different users are allowed in the same spectrum. A typical example is satellite transmission and fixed links. Because both users have directional antennas and as the satellite antennas point somewhat vertically whereas the fixed link antennas point horizontally, there is a fair degree of isolation between them. However, it is still necessary to maintain some geographical separation. 4.4 SPECTRUM PRICING Spectrum is a resource that can be traded and priced like any other resource commodity. In 1993 the ITU recommended that all spectrum users should pay a charge and a set of principles should be followed and that: [6] The pricing structure should be clear, transparent and comprehensive. Spectrum charge should be calculated fairly. If two users are using the same amount of spectrum in the same way, both should pay the same charge. Spectrum charge should be proportional to the amount of bandwidth used. The charges should reflect the spectrum s value to the society, i.e. if need be, frequencies used for public services should be subject to lower charges. Spectrum users should be consulted about any intended adjustments in spectrum charges. The pricing structure should reflect the scarcity of available spectrum and the level of demand for spectrum in different frequency bands. 15

27 4.4.1 Spectrum pricing requirements. Spectrum prices or charges are set to recover the cost of running a spectrum regulatory agency. The resources the spectrum management agency requires include: skilled labour, IT resources, investment in technical monitoring equipment, and expenditures to pay for participation in ITU and other international meetings. Administrative methods of setting spectrum prices are increasingly being supplemented by the use of market based methods for determining spectrum prices. In summary, the following are requirements of spectrum pricing: To cover the costs of spectrum management activity borne by the spectrum management authority or regulators. To encourage existing users to relinquish unused spectrum allocations To Act as incentive to consider alternatives to radio spectrum use, so freeing congested spectrum space. Increase the probability of new users gaining access to the spectrum Providing revenue to the government 16

28 4.4.2 Annual Current frequency spectrum fee schedule in Kenya Table 2.4 SERVICE DESCRPTION ANNUAL FEES PER STATION PER FREQUENCY IN KSH. MF/HF VHF/UHF 1.AERONAUTICAL STATION LICENCE A license to establish a radio station for carrying radio communication with aircraft station 4,800 4,800 2.AICRAFT STATION LICENSE 3.LICENSE FOR FIXED STATION OPERATING IN MOBILE SERVICE 4.MOBILE STATION LICENSE A license to establish a mobile station aboard an aircraft to operate in the aeronautical mobile service. A license to establish a radio communication station at a fixed location for carrying on a mobile Radio communication A license to install and use radio apparatus for transmitting and receiving aboard a vehicle, aircraft or a ship 4,800 4,800 18,700 5,000 5,610 2,900 5.PORTABLE STATION LICENSE. 6.COAST STATION LICENSE A license to establish a portable radio communication apparatus to operate in the mobile service. A license to establish a station and a land for carrying on a service with ship stations. 5,610 2,900 5,610 2,900 17

29 7.SHIP STATION LICENSE A license to install and use radio apparatus aboard ships 5,610 2,900 8.RADIO AMATEUR LICENSE A license to install and operate an amateur radio station 2,000 2,000 9.CITIZEN BAND RADIO LICENSE A license to operate a low power radio apparatus operating in the frequency bands 26925KHZ to 27403KHZ 1,000 Not applicable 10.PRIVATE PAGING SERVICE A license to operate a radio paging service for private use Not applicable 25, PUBLIC PAGING SERVICE A license to operate a radio paging service for public use (base station) Not applicable 140, RADIO PRESS RECEPTION LICENSE A license to establish a radio station to receive press message from stations transmitting multidestination radio press messages 10,000 10, Alarm systems The basic charge for each unit is Kshs.1250, but the specific charge for each particular customer is determined by using the maximum value in each grouping of 5; 5 for 1-5, 10 for 6-10, 15 for Fixed satellite earth stations The fee payable for fixed satellite earth stations is commensurate with the power and the occupied bandwidth and calculated on the basis of these parameters using the following formula; A fee per transmitter or carrier in Kenya shillings is given by; 18

30 Fee ( KShs). = k 1 log10 P nom (watts) + k 2 log 10 (P tot -1000) BW(KHz) (4.1) 25 watts 25 watts 8.5KHZ Where; K 1 =1 for the first 1KW of radiated carrier power. K 2 =0.2 for additional power above 1KW. 25 watts is the maximum power allowable for VHF base stations. 8.5KHZ is the maximum allowable RF bandwidth for VHF base stations. P nom is the nominal transmitter power. P tot is the total effective radiated power in watts. 15. Table 3.4 Broadcast stations fee per transmitter Service Amount in KShs. ERP power conditions Television broadcasting 360,000 ERP power 10KW As per formula (4.2) subject to a minimum of KShs. 360,000 ERP power >10KW 15.2.Radio broadcasting 30,000 ERP power 2KW 65,000 2KW<ERP power 5KW 130,000 5KW<ERP power 10KW As per formula (4.2) subject to a minimum of KShs. 130,000 ERP power >10KW Fee (KShs)= K 1 log 10 P nom (watts) + K 2 log 10 (P tot ) BW(KHz) K 3 (4.2) 25 watts 25 watts 8.5KHz Where; K 1 =1 for the first 1KW of radiated carrier power. K 2 =0.2 for additional power above 1KW. 25 watts is the maximum power allowable for VHF base stations. 8.5KHz is the maximum allowable RF bandwidth for VHF base stations. P nom is the first 1KW of the effective radiated power (ERP).. P tot is the total effective radiated power in watts. 19

31 K 3 =0.4 for TV broadcasting stations =5 for Radio broadcasting stations 16. Terrestrial links (fixed station license) The fee (KShs.) per transmitter per location is given by; Fee (KShs.) = RF bandwidth (KHz) x Number of K 1 x (4.3) 8.5 KHz RF channels Where; Unit fee= KShs for a 8.5KHz band K 1 =0.6 for frequency band <1700MHz =0.5 for frequency band 1700MHz to MHz =0.4 for frequency band >10000MHz 17 Mobile cellular networks 17.1 Exclusive spectrum assignment Bandwidth This is applicable to cases that have been assigned exclusive use of a specific bandwidth countrywide. This standing fee is to be paid annually for exclusive use of the bandwidth in addition to the usage fee that is detailed in equation (4.5) Fee (KShs)= assigned bandwidth (KHz) weighting factor (4.4) 8.5 KHz Where; Weighting factor to be used =6 Unit fee = KShs spectrum usage fees This is based on actual usage of the spectrum and depends on the number of TRXs in the network. Fee (KShs.) =43,000 n (4.5) Where; 20

32 n is the actual or equivalent number of 200KHz duplex TRXs estimated to be in use at the end of the year in review 8.5KHz is the maximum allowable RF bandwidth for VHF base stations Annual spectrum management cost of one TRX is KShs.43, Fixed wireless access networks 18.1 exclusive spectrum assignment bandwidth Fee (KShs.) = assigned bandwidth (KHz) weighting factor (4.6) 8.5 KHZ Where; Weighting factor to be used =6 Unit fee =KShs Spectrum usage fees This is based on actual usage of the spectrum and depends on the number of TRXs in the network Fee (KShs.) =100,000 n K 1 (4.7) Where; n is the actual or equivalent number of 1.75MHz duplex TRXs estimated to be in use at the end of the year in review Annual spectrum management cost of one TRX is KShs. 100,000 Weighing factor K 1 =0.8 for f<1ghz =0.7 for 1GHz f<6ghz =0.6 for 6GHz f<10ghz =0.5 for 10GHz f< 20GHz =0.4 for 20GHz 21

33 19 Trunked networks (mobile trunked radio license) 19.1 Exclusive spectrum assignment bandwidth Fee (KShs.) = assigned bandwidth (KHZ) K (4.8) 8.5 KHZ Where; K =6 Weighting factor to be used Unit fee=kshs spectrum usage fees This is based on the actual usage of the spectrum and depends on the number of TRXs in the network Fee (KShs.) =43,000 n K 1 (4.9) Where, n is the actual or equivalent number of 25KHz duplex TRXs estimated to be in use at the end of the year in review Unit fee = KShs.43, 000 for Annual spectrum management cost of one 25 KHz duplex transmitter. K 1 =1 for trunked public access mobile radio (PAMR) systems =3.5 for trunked private mobile radio (PMR) systems 20. Single channel radios The fee per transmitter per location is given by; Fee (KShs.) = RF Bandwidth (KHz) (4.10) 8.5KHz 22

34 4.5 SPECTRUM AUTHORIZATION Authorization is the process by which users are assigned spectrum resource and given license to transmit on a specific frequency or on a band of frequencies. Spectrum authorization activities include analyzing requirements for proposed frequencies in accordance with national plans and policies for frequency allocation and protecting radiocommunication systems from harmful interference. Spectrum authorization strategies are used to ensure proper use, facilitate reuse and to ensure effective global coordination of the limited spectrum resource, national frequency allocations must be consistent with; ITU Radio Regulations ITU Frequency Plans ITU-R Recommendations National legislation and operating procedures Parameters notified to ITU-R after assigning spectrum to a user Site name Directivity of the antenna Height of the antenna Effective antenna height in different azimuth Attenuation at different azimuth Site geography coordinates Altitude Frequency Necessary bandwidth Polarization Effective radiated power Transmission system 23

35 This parameters will be registered in the Master International Frequency Register at the ITU headquarters so that they will be referred to during international frequency co-ordination Administrative Methods of assigning spectrum Administrative method is a process whereby the regulator specifies detailed rules and constraints affecting how, where and when spectrum can be used and who can access it. Often it has involved specifying what equipment a licensee can use and at what power levels. This is a good way to control interference. However, these methods are often slow and unresponsive to new technological opportunities. In the administrative method there are two stages involved in authorizing spectrum use: The allocation stage; and The assignment stage. At the allocation stage, broad decisions on spectrum use are made on global and regional ITU radiocommunication conferences. The national spectrum regulator (CCK) prepare frequency allocation table on this basis, which usually impose further restrictions on spectrum use. Potential users make proposals for allocations. Once allocation has been determined, spectrum use is authorized at the assignment stage with the issuance of a license First come, first served basis First come, first served approach works best when the demand for spectrum is unlikely to exceed the supply. This is because there is no mechanism to ensure the spectrum is assigned to more efficient or higher value users. Sometimes this approach is used in circumstances where demand may exceed supply. First come, first served approach is currently used in Kenya to assign spectrum in bands for point-to-point links and private mobile radio, both of which tend to involve many small users of spectrum, with bespoke spectrum requirements and whose demands can change from year to year. In these circumstances, this approach provides a flexible approach to assigning spectrum with low transaction costs compared with the alternatives of auctions or comparative tenders. In bands where congestion arises, the spectrum regulator will have few options for promoting more efficient use of the spectrum. Administrative incentive pricing should have a role to encourage the reassignment of spectrum from low to high value users. 24

36 In practice, the national spectrum regulator do not literally assign spectrum to whoever demands it under the first come first served approach, but rather use administrative rules to determine the frequencies and bandwidth an applicant is permitted. These include rules related to optimizing the use of frequencies Comparative Selection Comparative refers to a process whereby licenses are assigned to the best qualified of the competing applicants. Key issues in the design of comparative selection procedures are the criteria used to choose the winning applicant, the precision and transparency of the criteria, the weighting given to different criteria and the transparency of reasons for the final decision. In most countries comparative selection procedures happen behind closed doors with decisions made by a committee. These hearings are time consuming, expensive and are criticized for assigning licenses based on insignificant and arbitrary differences. In some circumstances applicants can only guess at what is required in putting together their bids and outcomes can be subject to undue influence. The winning bidder is therefore unlikely to be the most economically efficient supplier. Opaque comparative selection processes are also susceptible to legal challenge which can in turn lead to long delays in awarding licenses and substantial loss of economic welfare. Comparative selection was used in assigning spectrum to digital signal distribution for digital broadcasting Market Methods Attention has recently been focused on creating genuine markets for spectrum licenses under which both the ownership and use of spectrum can change in the course of a licensee's operation Spectrum Trading Spectrum trading is a mechanism whereby rights and any associated obligations to use spectrum can be transferred from one party to another by way of a market-based exchange for a certain price. The right to use the spectrum is transferred from one user to another and a sum is paid by the new user for spectrum. Spectrum trading contributes to efficient use of spectrum because a trade will only take place if the spectrum is worth more to the new user than it was to the old user, reflecting greater economic. Spectrum trading includes; Leasing of rights to a third party for a specified period of time 25

37 Change of ownership Change of ownership, reconfiguration and change of Auctioning Auctions involve assigning licenses to those who bid the largest sums of money and often applicants are only eligible to bid if they pass certain pre-qualification tests like relating to technical and financial competence. In addition, non-monetary requirements may be specified in license conditions requiring licensees to provide particular services like for broadcasting services licenses may specify the program formats, minimum amounts of programming of certain types or coverage obligations. Auctioning ensures that any newly released spectrum into the market is acquired by those who value it the most. Spectrum auctions have the following advantages; Efficiency: the assignment of licenses leads to licenses being awarded to those who value it the most and those who contribute the most to economic activity through using spectrum. Competition: spectrum rights are issued in a way that helps promote effective competition. Transparency: ensures that the process of selection is without corruption and undertaken expeditiously Current spectrum utilization in Kenya [source CCK database] Government Major user of all bands. 26

38 Telkom 387 links for public telephony; 2GHz, 4GHz, 6GHz, 7GHz, 8GHz and 10/11GHz. 45 radio links for medium capacity public telephony traffic ( channel capacity) in 400MHz and 800MHz band. 42 low capacity (12-24channels) 230MHz and 450MHz band. 243 WLL trunked rural access systems. 122 single channel capacity VHF radio links. Two satellite C-band (4/6 GHz) earth stations at longonot and Kericho. Safaricom GSM / MHz, / MHz. Backhaul links. 6/7 GHZ: 144 links. 8GHZ: 88links. 13GHZ: 12 links. 15GHZ: 346 links 18GHZ: 2links 26GHZ: 13links Airtel GSM / MHZ / MHZ. Backhaul links. 27

39 6/7GHZ: 95links. 15GHZ: 281links. 26GHZ: 326links. VSAT 5 commercial VSAT operators. 79 private VSAT operators. Local loop operators 14 LLO s assigned spectrum mainly in the 1900MHz band. Public data network operators 16PDNO s assigned frequencies mainly in the 3.5GHz as well as 5.8GHz ISM band for their access network. Broadcasting Television: 119 channells,57 on air and others in various stages of implementation 294 FM stations, KBC :MF services at 11 locations countrywide, HF from Komarock and Langat Most of these FM radio stations and television channels do not transmit nationally but transmit within major towns and local areas on frequency reuse scheme. Private radio networks HF and VHF: 3,641 private radio networks with 4,795 base stations and 22,874 mobile and portable stations 611 Aircraft stations 90 radio amateur 28

40 Aeronautical services 115 radio networks countrywide for radio navigation, distress and safety, radars, intra-communication, Maritime services Kenya maritime and Kenya Ports Authority: Extensive VHF network, MHz for ship calling frequencies, port operations, ship-to-ship communications, ship-to-shore, distress and safety, search and rescue [source CCK database] Unlicensed Spectrum Unlicensed Spectrum is a free band where anyone can transmit without a license while complying with the rules that are designed to limit interference. Industrial, Scientific and Medical (ISM) band is an example of unlicensed spectrum band but with some management in terms of power restrictions on individual users. Significant innovations have emerged in these band like BlueTooth, Wi-Fi and W-LAN in the 2.4 GHz which have led to call for management of it. 29

41 4.6 Spectrum monitoring and inspection Effective spectrum monitoring processes support activities centered on making interference-free assignments and includes the use of data and electromagnetic compatibility (EMC) verification activities. As well, monitoring and compliance activities are needed to ensure user compliance with both license conditions and technical standards. Furthermore, spectrum use planning and resolution of spectrum scarcity issues can be accomplished through study and analysis of spectrum occupancy data. Understanding the level of spectrum use or occupancy in comparison to assignments is important for efficient use of the spectrum resource. In summary, the following are objectives of spectrum monitoring: To ensure compliance with the national and international spectrum management regulations to shape and sustain radio environments and user behavior, maximizing the benefit of the spectrum resource to the society Identifying and locating of known or unauthorized transmissions. To support in spectrum engineering analysis including validation of tolerance levels, spurious emissions, determining the probability of interference and development of band-sharing strategies. Improving spectrum efficiency by determining actual frequency usage and occupancy, assessing availability of spectrum for future uses. To determine frequency bands experiencing congestion, interference or coordination problem. Investigate and identify stations causing interference. Provide statistics on use of spectrum. Frequency spectrum monitoring is normally done through compliance returns, inspections or using of monitoring tools and instruments Spectrum Monitoring Technology Fixed, remote and mobile monitoring equipment are combined to provide tools for monitoring. Monitoring equipment and integrated software tools are very complex and expensive. Fortunately, advances in computerization, monitoring technology, and security techniques have permitted greater use of remote unmanned monitoring techniques involving integrated spectrum 30

42 observations. The types of monitoring equipment include; antenna, spectrum analyzers, and radio direction-finding equipment (RDF). These types can further categorized by frequency range (HF, VHF and UHF.) and signal type (analogue or digital). Simple systems for VHF/UHF monitoring can be comprised of several fixed antennas, receivers and spectrum analyzers Monitoring Equipment Antennas An antenna is simply an electronic component designed to transmit or receive radio waves. Antennas are linked to either radio receivers or signal generators of direction-finding equipment. Different antenna types are needed for different coverage of the frequency ranges. Examples of different antenna types are depicted below. Figure 7.4 monitoring antenna with vertical dipole Direction finding antennas Figure 8.4mobile monitoring station 31

43 Spectrum Analyzers Since different frequencies are allocated to various radio services, it is important that each service operate at the assigned frequency and within the allocated channel bandwidth. Due to scarcity of spectrum, transmitters should be planned to operate at closely spaced adjacent frequencies. Common measurements taken by a spectrum analyzer include frequency, power, modulation, distortion, and noise. Understanding the spectral content of a signal is important, especially in systems with limited bandwidth. In digital modulation techniques, there are additional measurements which need to be taken, these are error vector magnitude (EVM) and phase error versus time. The types of spectrum analyzers used are: Fourier and Vector Signal Analyzers. Fourier signal analyzers measure the time-domain signal and then use digital signal processing (DSP) techniques to perform a fast Fourier transform (FFT) and display the signal in the frequency domain showing both phase as well as magnitude of the signal. Vector signal analyzers (VSA s) operate like Fourier signal analyzer but offer faster, higherresolution spectrum measurements, demodulation, and advanced time-domain analysis. Radio Direction-Finding Equipment Radio Direction-Finding, is the technique for determining the direction of a radio transmission. Radio direction-finding uses triangulation method to determine the location of a radio transmission and also locate the source of radio frequency interference. There are two common technical approaches to radio direction-finding. The first approach involves the use of directional antennas which are designed to be more sensitive to signals received in some directions rather than in others. As the antenna is turned in various directions, a signal being received will either increase or decrease in strength. The direction in which the signal is strongest is the likely direction in which the radio transmitter is located. The movement of the antenna and the determination of the peak signal strength can be made by a human operator or can be done automatically by electronics. The second approach exploits the effects of phase shift. Fixed antennas are deployed in a precise geometric pattern and electronics system switches between the antennas very rapidly. By computing the amount of phase shift present on the signal from antenna to antenna, a direction to the signal source can be computed. 32

44 Figure 9.4Image of triangulation location of a transmitter Designing Spectrum Monitoring Systems State-of-the-art spectrum monitoring equipment is highly integrated. Integration typically involves the use of graphical user interface (GUI) based spectrum management tools and systems which are specifically designed to operate multiple electronic components simultaneously and remotely over data protocols such as TCP/IP. This allows for an integrated network system for management of the radio spectrum using remote devices. Remote devices permit access to monitoring equipment from anywhere through compatible computer, a modem and a telephone line or network connection (LAN or WAN). There are organizational and functional aspects to architecting spectrum monitoring systems. Organizational components include centralized, regional and remote locations for siting of monitoring equipment in stations and operational staffing or use of unmanned remote capabilities. Functional components of spectrum monitoring systems include: central monitoring control; operational consoles for operation of equipment and analysis of data; data networking and management systems for data communications. Remote devices can be controlled in several ways: Locally from the server; Remotely across a LAN; Modem over a WAN. 33

45 4.6.4 Spectrum monitoring capabilities in Kenya. The following are monitoring stations in the country with various monitoring capabilities. Four fixed monitoring stations with VHF/UHF capability in Kabete, Industrial area, Mazeras and Mombasa and one fixed monitoring stations monitoring stations with HF/ VHF/UHF capability in Kahawa, Two remote monitoring stations with HF capability in Kitale and Garissa. Two mobile monitoring stations with HF/VHF/UHF/SHF capabilities. The above systems are fully integrated through a communications network that utilizes leased digital data lines, microwave links, HF links, Dial up PSTN and GSM lines to enable remote control and monitoring from national spectrum monitoring and control centre headquarters at Kabete Radio spectrum management and monitoring system layout in Kenya 34