RADIO REGULATION AND SPECTRUM MANAGEMENT FOR SATELLITE COMMUNICATIONS

Part 1

Les Barclay

1 INTRODUCTION TO THE RADIO SPECTRUM AND UTILISATION

1.1 Introduction to the needs for spectrum management

For line or optical-fibre telecommunication systems, where the system characteristics, standards and protocols to be used do not generally affect unconnected systems, it is in principle only necessary to reach agreement between those concerned with making and using the systems. In contrast, radiocommunication systems and services cannot be considered in isolation. Radiation into the atmosphere or space will spread and overshoot the receiving antenna, dependent on the propagation characteristics, and may then adversely affect other radio systems. Management of use of the radio spectrum and radio regulation is thus essential, to control the chaos which might well ensue.

The radio frequency spectrum is limited in extent and the most useful parts of it are crowded. The growth in demand - for communications; for increased data rates with higher quality; and particularly for mobility - increases the crowding and necessitates the extensive application of co-channel frequency sharing. It is easy to see that two radio systems occupying the same frequency band have the potential for causing harmful interference to each other. The extent of the interference depends on system characteristics and the robustness of the modulation, on the acceptable quality and availability for the service, and also on the propagation characteristics of both the wanted and interfering paths.

As an example of this, in some frequency bands, e.g. below say 30 MHz, ionospheric refraction may permit signals to be propagated world-wide, so that full international coordination between users who wish to use the same or adjacent frequencies is necessary. At higher frequencies satellite communication systems also need world-wide coordination, both for the radio frequencies and system parameters and also for the satellite orbit positions. Terrestrial services at VHF and higher frequencies may have a more limited propagation extent, but even so interference may well be caused far beyond national boundaries. In such cases regional agreements and regional coordination is necessary.

To permit maximum spectrum occupancy, it is necessary to design modulation methods which can transfer the information with minimum impact - either by using the minimum bandwidth (the traditional approach) or by minimising the product of bandwidth, power density, time for transmission, etc. in some other way.

Although not the main need as far as regulation is concerned, the advantages to industry and users of standardisation of equipments and systems within Europe and across the world are also very significant. ETSI has been established to provide standard specifications for equipment and there are now procedures for the type approval of manufactured equipment as a prerequisite for licensing.

In addition the all pervasive use of radio systems for a wide variety of purposes in domestic, business and industrial environments, means that unwanted susceptibilty of non-radio electronic equipment to radio emissions and also the unwanted and unnecessary radiation from transmitters and receivers must be controlled and regulated if the maximum use of radio is to continue. These electromagnetic compatibility aspects are dealt with within the European Union by the Radio and Telecommunication Terminal Equipment Directive, and also by the specification of relevant radio equipment parameters by the CEPT and by CENELEC.

Despite good system design and implementation, electromagnetic radiation cannot be strictly confined to the ray path between the transmitter and the receiver. Antenna beams have a finite beamwidth,

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allowing the spreading of energy and perhaps exciting unforeseen propagation modes. Transmitter powers are designed to ensure an adequate received signal during periods of signal fading due to propagation conditions, so that in most circumstances more signal is radiated than is strictly necessary. Moreover, signal levels capable of causing unacceptable interference to other co- or adjacent-channel systems will be at a substantially lower level than that needed for a high quality wanted signal; thus the transmitted energy will overshoot the receiving antenna and cause interference at longer ranges.

If these effects could be confined within national boundaries, then the planning and control of radio emissions would be a wholly national matter. However this is often not the case; radio signals extend across national boundaries and there is a consequent need to find ways to achieve regional and international coordination and agreement over the use of radio. In addition there are similar arguments concerning the use of the radio transmissions from satellites, particularly for satellites in or near the important geostationary orbit. In fact the extensive use of radio means that the available radio frequency spectrum, limited by propagation characteristics and the state of economic equipment development, is under stress. Thus there is a need to ensure good spectrum utilisation if room is to be found for new radio systems and services as they emerge.

Furthermore, there are other benefits to be had from agreements on system specification and modulation methods. Some standardisation here will give economic and convenience benefits to the user and manufacturer of equipments by increasing market size and assuring some stability in product types.

Thus there is a need for radio regulation at several levels: nationally, regionally and internationally.

Nationally, the administration has the right to authorise any transmissions. In addition, for the effective use of the spectrum and to ensure a good level of performance for the user it is necessary to plan and control the use of radio, typically by the use of licensing and the associated charges. In the UK, the national authority is OFCOM, an Agency which combines the scope of several bodies concerned with various aspects of the regulation of telecommunications and broadcasting. Until the end of 2003 the radio regulatory function was undertaken by the Radiocommunications Agency.

Note that a radio station on a satellite is not within the national territory of any country, so there is a particular problem in regulating satellite systems. This is covered by international agreements.

Regionally, particularly in Europe where countries are small and where there are common objectives through the European Union, there is a need to coordinate the use of radio so as to avoid interference, and also a need to employ common equipment specifications and regulations for usage so as to provide a European-wide market and to permit cross-border use, e.g. of cellular telephones, etc. These objectives are achieved through:

The Electronic Communication Committee (ECC), of the Conference of European Post and Telecommunication administrations (CEPT), which deals with spectrum utilisation and frequency planning matters, and

The European Telecommunications Standards Institute (ETSI) which deals with equipment specifications and performance. These notes will not address such aspects, although they will be of increasing importance as specifications are prepared for a wide variety of equipments, and such standards may in some cases have the authority of European Directives.

Internationally, the wider goals are very similar. There is a need to plan for good spectrum utilisation and for coordination between administrations, and to ensure, as far as political and commercial constraints allow, that the parameters of equipment specifications which affect spectrum utilisation have world wide agreement. Particularly for space systems, where transmissions from a geostationary satellite may illuminate nearly half of the earth’s surface, and a satellite in a lower orbit may over-fly every country in the world, the need for world-wide agreement is obvious. This function is undertaken by the International Telecommunication Union (ITU), based in Geneva; most of these lectures will

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concentrate on the agreements reached in the ITU, since this provides the overall framework within which Regional and National provisions are set.

1.2 The Radio Spectrum

Radio waves are electromagnetic waves, subject to the conditions contained in the Maxwell equations. Electromagnetic waves may exist with an extremely wide range of wavelengths, and with corresponding frequencies, where the product of frequency in Hertz and wavelength in metres is the velocity of em waves in free space, about 3 x 108 m/s.

It is convenient to consider that the radio spectrum lies in the range of frequencies between say 3 kHz and 3 THz, although significant use is within the range 10 kHz to say 50 GHz; the range covered in detail by the ITU Radio Regulations extends from 9 kHz to 275 GHz. The conventional nomenclature for the spectrum is summarised in Table 1 below:

Table 1Frequency Bands defined by the ITU

Band No

Symbols Frequency Range Wavelength Corresponding metric sub-division

Metric abbreviations for the bands

ELF below 3 kHz Greater than 100 km (unofficial designation)

4 VLF 3 kHz - 30 kHz 100 km - 10 km Myriametric waves

B.Mam

5 LF 30 kHz - 300 kHz 10 km - 1 km Kilometric waves B.km6 MF 300 kHz - 3 MHz 1 km - 100 m Hectometric

wavesB.hm

7 HF 3 MHz - 30 MHz 100 m - 10 m Decametric waves B.dam8 VHF 30 MHz - 300 MHz 10 m - 1 m Metric waves B.m

9 UHF 300 MHz - 3 GHz 1 m - 100 mm Decimetric waves B.dm10 SHF 3 GHz - 30 GHz 100 mm - 10 mm Centimetric waves B.cm 11 EHF 30 GHz - 300 GHz 10 mm - 1 mm Millimetric waves B.mm12 300 GHz - 3 THz 1 mm - 100 m Decimillimetric

waves

Note 1: “Band number N” (N = band number) extends from ) 0.3x10N to 3x10N HzNote 2: prefix: k = kilo (103); M = mega (106); G = giga (109); T = tera (1012); m = milli (10-3); = micro (10-6)

In some cases letter designations are used for some frequency bands. These are not recommended as the precise limits are not universally recognised. Some of these letter designations, as listed by the ITU, are given in Table 2.

Radio spectrum usage for communications and navigation purposes began at the lower frequencies, and moved to higher frequencies as the demand for bandwidth grew and as necessary technologies were developed. However the effect of the Earth’s atmosphere and of terrain and other obstacles varies with frequency. The combination of propagation characteristics and bandwidth has led to different uses of the various parts of the spectrum. These uses may not in fact be ideal for the purpose since an established use with large investment in equipment restricts the practical possibilities for moving that use to another part of the spectrum. Spectrum management involves a combination of technical considerations, the constraints of established uses, the possibility and practicality of using equipment

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with non-ideal emission and susceptibility specifications, and the economics of equipment design, construction, implementation and of the use of improved technology and system design.

Table 2Letter symbols used to denote some frequency bands

(not recommended for use)

Letter symbol

Radar (GHz) Space RadiocommunicationsSpectrum region

GHzExamples

GHzNominal

designationsExamples

(GHz)L 1 – 2 1.215 - 1.4 1.5GHz band 1.525 - 1.710S 2 – 4 2.3 - 2.5

2.7 - 3.42.5GHz band 2.5 - 2.690

C 4 – 8 5.25 - 5.85 4/6 GHz band 3.4 - 4.24.5 - 4.8

5.85 - 7.075X 8 – 12 8.5 - 10.5

Ku 12 – 18 13.4 - 14.015.3 - 17.3

11/14 GHz band12/14 GHz band

10.7 - 13.2514.0 - 14.5

K (1) 18 – 27 24.05 - 24.25 20 GHz band 17.7 - 20.2Ka(1) 27 – 40 33.4 - 36.0 30 GHz band 27.5 - 30.0

V 40 GHz bands 37.5 - 42.547.2 - 50.2

(1) For space radiocommunications K and Ka bands are often designated by the single symbol Ka.

1.3. Spectrum use

It is useful to review the way in which each decade of the spectrum is used. Although the conventional way of describing the spectrum in decade frequency bands does not match the applications or the propagation characteristics very well, it is used here as a convenient short-hand. None of the frequency boundaries indicated are clear and precise in terms of differing usage.

1.3.1 ELF (below 3 kHz) and VLF (3-30 kHz)

Typical services: world-wide telegraphy to ships and submarine communications; navigational aids (e.g. Omega – now closed); time standards; worldwide communication, mine and subterranean communication;

System considerations: even the largest antennas are only a small fraction of a wavelength with low radiation resistance; difficult to make transmitter antennas directional; bandwidth very limited, only low or very low data rates; high external atmospheric noise so that inefficient receiving antennas are satisfactory

Propagation: In the Earth-ionosphere waveguide, relatively stable propagation; affected by thick ice masses (e.g. Greenland); asymmetric propagation east/west and west/east. Propagation through sea water which has significant skin depth for these wavelengths.

Comment: There are no international frequency allocations below 9 kHz. Limited use of frequencies below 9 kHz for military purposes.

1.3.2. LF (30-300 kHz)

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Typical services: long-distance shore-to-ship communication; fixed services over continental distances; broadcasting; time signals

System considerations: vertical polarisation (for ground wave propagation, and for antenna efficiency); large efficient antennas possible; directional antennas very large; high atmospheric noise; limited bandwidth.

Propagation: up to several thousand km; ground wave, strong sky wave at night, slow fading

1.3.3. MF (300 kHz -3 MHz)

Typical services: broadcasting; radionavigation; maritime mobile communications;

System considerations: half wavelength vertical antenna at 1 MHz is 150 m high; directional antennas possible, magnetic receiving antennas;

Propagation: ground wave more pronounced over sea; strong sky wave absorption during the day, but little absorption at night; high atmospheric noise levels

1.3.4. HF ( 3-30 MHz)

Typical services: international broadcasting, national broadcasting in tropical regions; long-distance point-to-point communications; aeronautical and maritime mobile communications;

System considerations: arrays of horizontal dipoles; log-periodic antennas (vertical or horizontal), vertical whip antennas, frequency agility essential; crowded spectrum needing good intermodulation performance; external noise environment varies with time and location. Bandwidths up to about 6 kHz

Propagation: propagation up to world wide distances by ionospheric sky-wave, very

variable in time. Propagation window between MUF and LUF (maximum and lowest usable frequencies) varies from a few MHz to about 20 MHz

Comment: necessary to change the operating frequency several times during 24 hours. Broadcasting uses schedule of frequencies. Fixed and some mobile services use intelligent frequency adaptive systems. Continues to provide the main intercontinental air traffic control system. Most modulation bandwidths may exceed the correlation bandwidth. New digital modulation methods (DRM) now being introduced for broadcasting.

1.3.5. VHF ( 30-300 MHz)

Typical services: land mobile for civil, military and emergency purposes, maritime and aeronautical mobile; sound (FM and DAB) and (outside UK) television broadcasting (to about 100 km); aeronautical radionavigation and landing systems; cordless telephones; paging; very limited little LEO satellite systems. The lowest range of the frequencies which may be used for satellite services (ionospheric effects prevent satellite use at lower frequencies, and the ionosphere will cause significant effects in the VHF range)

System considerations: multi-element dipole (Yagi) antennas, rod antennas suitable for vehicle

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mounting, atmospheric noise small but man-made noise significant. Some use for meteor burst communications

Propagation: usually by refraction in troposphere; reflections may cause multipath on line-of sight paths; screening by major hills, but diffraction losses generally small; some anomalous propagation due to refractivity; unwanted ionospheric modes due to sporadic E and meteor scatter. Substantial Faraday rotation and ionospheric scintillation on Earth-space paths

1.3.6. UHF (300 MHz - 3 GHz)

Typical services: television broadcasting; cellular and personal communications; TETRA; satellite mobile; GPS; important radio astronomy bands; surveillance radars; terrestrial point-to-point service; radio fixed access; telemetry; cordless telephones (DECT); tropospheric scatter links.

System considerations: small rod antennas; multi-element dipole (Yagi) antennas; parabolic dishes for higher frequencies; wide bandwidths available

Propagation: : line-of sight and very slightly beyond; tropospheric scatter for transhorizon paths, screening by hills, buildings and trees; refraction effects; ducting possible; ionospheric scintillation

1.3.7 SHF ( 3-30 GHz)

Typical services: fixed (terrestrial point-to-point up to 155 Mb/s); fixed satellite; radar; satellite television; GSO and NGSO fixed satellite services; remote sensing from satellites; wireless fixed access systems

System considerations: high-gain parabolic dishes and horns; waveguides; major inter-service frequency sharing; wide bandwidths

Propagation: severe screening; refraction and ducting; scintillation; rain attenuation and

scatter increasing above about 10 GHz; atmospheric attenuation above about 15 GHz, trans-ionospheric effects becoming small.

1.3.8. EHF (30-300 GHz)

Typical services: line-of sight communications, future satellite applications; remote sensing from satellites; WFA; fixed service using stratospheric platforms

System considerations: small highly directional antennas; equipment costs increase with frequency; little use at present above 60 GHz; very wide bandwidths; short range

Propagation: severe difficulties: screening; atmospheric absorption; rain; fog; scintillation

1.4. Measures of Spectrum Usage

1.4.1. Spectrum utilisation

In an ideal world with perfect transmitters, receivers and antennas, with a constant propagation environment and with a steady information flow, it would be possible to pack emissions into the spectrum and use this limited resource to a maximum extent. Even if possible, this theoretical approach would be undsesirable since the spectrum usage would then be inflexible and could nto accommodate

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growth in demand. In practice the real situation is very different and measures of how near spectrum usage approaches a theoretical maximum are difficult to determine.

One significant reason for this is the economic and competitive environment. There will always be some pressure to use equipments with imperfect characteristics since these may be cheaper, smaller or lighter, and may be able to be manufactured and marketed faster. The radio regulator aims to ensure an agreed minimum standard for equipment specification, on the one hand to ensure equitable access to a competitive environment, and on the other to provide a basis from which spectrum planning may undertaken.

Propagation characteristics vary markedly with frequency, location and time. For mobile and transportable systems the location of one or both ends of a circuit will also vary. For a reliable service, suitable propagation will be needed for nearly all of the time (say 95 to 99.99% of the time, dependent on the needs of the service). Predictions for such extreme conditions will inevitable be less well specified than for median conditions and an allowance for a statistical confidence level may be large.

Nevertheless, despite the problems an assessment should be made of the effectiveness with which the spectrum is being used.

Spectrum Utilisation (U) may be defined conceptually as:

U=B x S x T [1]

where B is the bandwidth (B),S is the geographic space or volume occupied (desired or denied)

and T is the time.

Such a definition however introduces more uncertainties.

The bandwidth for narrow band systems is related to the information rate, but more complex modulation methods may permit more bits of information to be transmitted per Hertz of bandwidth, usually with a requirement for a more perfect propagation channel. The use of modulation methods which deliberately spread the information over a wider bandwidth introduces another complication, Here it may be necessary to consider a factor related to the power density across the bandwidth, since such methods may be designed for co-frequency, co-located systems.

Geographic space is a concept which is also related to the application. For area coverage systems such as broadcasting or mobile applications the required space is the defined coverage area over the ground. For other kinds of application the concept is harder to visualise; for point to point communications presumably the desired geographic space is confined to the direct path between the terminals, and for geostationary satellite networks it may just be the one-dimensional orbit spacing around the geostationary arc.

Thus it may be more relevant to spectrum utilisation in terms of the geographic space denied to other users. In this case it is also necessary to include the effects of radiated power greater than that actually needed, antenna directivity, overshoot beyond the wanted receiver location and the probability of extended propagation for small percentages of the time.

It may also be noted that for passive applications such as radio astronomy, there are no transmissions, but a large geographic space may still be required to protect the receivers against interference

As an example of space denied, Figure 1 shows diagramatically the interference caused on a link of length Lc in free space between a transmitter station (A) and a receiver station (B), which form an independent system, by another equally independent system with stations A' and B'

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Figure 1. Representation of space occupied volumes

This figure shows the areas of space covered by the radiation patterns of the transmitter and receiver antennas. They are approximated by spherical sectors. The solid line show the boundaries of the interference space of volume V, determined by the level of the maximum permissible noise power which may be caused on B' by A. The broken lines show the boundaries of the volume determined by the equivalent power of emissions from station A' which may cause interference at station B. Thus a station B', of the same type as B, and belonging to a different link, cannot be sited within the solid line, since A will cause to B' interference in excess of the permissible level. Likewise, a station A' of the same type as A and belonging to a different link cannot be sited within the broken line contour. Outside these contours, there are no restrictions on the siting of transmitter and receiver stations for reasons of mutual interference.

The time factor may be unity for broadcast systems, but will be substantially smaller for some other applications. TDMA systems clearly use a predetermined fraction of the time for each communication link. Intermittent uses such as telephone and mobile systems only occupy the spectrum for a part of the time and this is assessed by estimating the traffic load in Erlangs.. For some applications, particularly within one kind of service where there is a common requirement, a uniform equipment specification, and regular channelisation, variants of the utilisation definition are used. For example for land mobile purposes the intensity of spectrum utilisation is sometimes quoted in terms of users per MHz per square kilometre.

It should also be noted that although spectrum efficiency is an important factor, because it allows the maximum amount of service to be derived from the radio spectrum, it is not the only factor to be considered. Other factors to be included in the selection of a technology or a system include the cost, the availability of equipment, the compatibility with existing equipment and techniques, the reliability of the system, and operational factors.

1.5 Effective Spectrum Utilisation

It might be considered that the goal of spectrum management would be to achieve that most efficient use. However, technically efficient use of the radio spectrum might be regarded as requiring perfect equipment, with no unwanted emissions from transmitters and receivers, and no susceptibility to unwanted signals in receivers. The modulated emissions would be confined entirely to within the necessary bandwidth. Antennas would have very high gains aimed accurately along the dominant radio path. Services would be interference limited for the required quality of service, giving the maximum extent of frequency reuse. Thus improvements in efficiency would then depend on improving the propagation modelling and the statistical treatment, and on the use of better modulation methods, or dynamic channel assignment procedures, etc.

On the other hand in practical circumstances it will be most beneficial to seek the most effective use of the spectrum. The most effective use is likely to be achieved by striving for efficient use to the extent

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which is practically possible (e.g. by accepting some level of unwanted emissions and by using modulation techniques which extend beyond the necessary bandwidth, etc) and by accepting compromises to the expected quality of service, etc. More importantly effective use will take account of factors which are not primarily concerned with spectrum use. These would include manufacturing tolerances, the availability of economic technologies, marketing and the need for rapid deployment, competition and government and regulatory requirements. These may have a significant impact on the spectrum usage and on operational frequency reuse distances.

2 THE INTERNATIONAL TELECOMMUNICATION UNION AND THE RADIO REGULATIONS

2.1. Introduction

The forerunner of the present ITU was established in 1865, to deal with the emerging technical and financial problems for international telegraphy. With the advent of radiocommunications at the end of the century, the scope of the ITU expanded and the first radio conference was held in 1907. This meeting agreed, for example, the first distress and emergency codes and procedures. Radio usage has continuously expanded through this century. In 1927 the International Radio Consultative Committee (CCIR) was set up, to give technical advice to the administrations which form the ITU. This committee worked alongside two committees concerned with line communications, the CCIF and the CCIT (which later merged to form the CCITT).

With the great growth of the use of radio, and the extension to higher frequencies, which expanded substantially during the second world war, there was a need to modernise the ITU and this was done at a World Administrative Radio Conference held in Atlantic City in 1947. The principles of the ITU’s operations were then largely unchanged for more than forty years, during which time there was further very substantial growth in the use of radio and the introduction in the 1960s of satellite communications. Membership of the ITU is primarily the Member States (in some circumstances referred to as “administrations”), but there is now an increased emphasis on the need and importance of participation by other members: the Registered Operating Agencies (ROAs) and Scientific and Industrial organisations (SIOs).

In 1993 the ITU was restructured, but before describing the present organisation it is useful to briefly describe the organisation as it existed between about 1960 and 1992, since these older arrangements are still sometimes referred to, and a description will aid in understanding the way in which current provisions were established.

2.2 The old ITU

The top-level management of the ITU is the Plenipotentiary Conference, where the Members of the Union, the Telecommunication administrations or agencies of the various Member States, met at about 5 year intervals to revise the ITU Constitution and Convention, which set the scope, policy and rules of procedure, etc. and to elect a number of senior officials. The Final Acts of the Plenipotentiary Conferences are signed by the Administrations present and have the force of International Treaties. Like all ITU Conferences, voting is on the basis of one vote for each Member State. The more routine management was controlled by an Administrative Council, comprising a group of elected administrations, which met annually and supervised the meeting programme, the budgets, etc.

The headquarters of the ITU is in Geneva, adjacent to the United Nations buildings; indeed the ITU has been a specialised Agency of the UN since 1947. The elected Secretary General and Deputy Secretary General have offices at the headquarters and run a general secretariat, providing general leadership and common services to the other organs of the ITU.

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Prior to 1993, the organs comprised:

The International Frequency Registration Board, five elected members with permanent offices, and a large staff which handled the IFRB’s responsibilities.

The CCIR secretariat, led by an elected Director The CCITT secretariat, led by an elected director

The General Secretariat included a Bureau for Telecommunication Development, to assist developing countries and to promote the best use of telecommunications throughout the world.

So far as radiocommunication is concerned, the most important activity of the ITU was the series of World Administrative Radio Conferences (WARCs). The Agendas for these meetings were set by the Administrative Council as required to deal with developments in radio usage. The output of WARCs were revisions to all or part of the Radio Regulations, and these constituted international treaties. The Radio Regulations determined the overall usage of the spectrum by allocating blocks of spectrum to different radio services. In some cases WARCs were concerned with a priori frequency assignment planning, to take account of the anticipated requirements of the administrations. Wide ranging WARCs were held in 1947, 1959, and 1979 and these reviewed the allocations over the whole of the spectrum - in view of the complexities of this process it seems unlikely that such a wide ranging agenda will ever be attempted again. These major WARCs led to a series of specific WARCs in subsequent years which dealt with particular radio services in parts of the spectrum.

In addition to World Conferences, Regional Conferences were also held as needed to deal with Regional planning matters. The Radio Regulations divides the World into three Regions:

Region 1: Europe, Africa, the Arabian peninsular and the countries of the old USSR

Region 2: The Americas

Region 3: South and East Asia, Australasia and the Pacific

2.2.1 The International Frequency Registration Board

The IFRB senior and expert members who were elected at the Plenipotentiary Conferences. The formed an impartial body which could interpret the Radio regulations in cases of dispute. The Radio regulations specified the function of the Board and its staff in registering frequency assignments and assessing the possibility of incompatibility and interference.

To undertake this work, the IFRB had a large permanent staff in Geneva.

2.2.2 The International Radio Consultative Committee

The CCIR secretariat, under the Director, supported the study activities of the CCIR which were undertaken by the Administrations, ROAs and SIOs. The major event was the CCIR Plenary Assembly which took place every 4 years. The Plenary Assembly established a number of Study Groups, received reports of the work done, approved Questions for further study, approved Recommendations prepared by the Study groups and agreed the procedures for the approval of other texts, such as Reports and Handbooks. In the period 1990-93, the Study Groups were:

SG1 Spectrum utilisation and monitoringSG4 Fixed-satellite service

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SG5 Propagation in non-ionized mediaSG6 Propagation in ionized mediaSG7 Science services (space research, radio astronomy, standard frequencies and

time signals)SG8 Mobile, radiodetermination, amateur, and related satellite servicesSG9 Fixed serviceSG10 Broadcasting service (sound)SG11 Broadcasting service (television)SG12 Interservice sharing and compatibilityCMTT Television and sound transmission (a joint group with CCITT)

This set of Study Groups reflects the changes made at the 1990 Plenary Assembly, particularly the establishment of SG12 (later renumbered as Study Group 2) to deal with urgent sharing issues which it was thought could not be handled in a timely and equitable way within the single service study groups.

Up until 1990 the Study Groups each met at roughly 2-yearly intervals, as “Interim” and “Final” meetings, preparing work for approval at the 4-yearly Plenary Assembly. During the Study Group meetings, studies were undertaken in Working Groups, which dealt with particular aspects of the scope of the work. It had been found however that this intermittent activity could not respond to urgent needs, so a series of Interim Working Parties were established as required. These had a continuing existence between meetings, in principle working by correspondence, but also meeting as necessary.

A particularly important task for the Assembly and the Study groups was the preparation of technical reports to provide the basis for the deliberations of WARCs. This work did not fit with the regular CCIR cycle and special arrangements were made and the preparation collated and finalised at a special preparatory meeting or a meeting of a conference preparatory group.

2.3 Transition

The ITU has been constrained for many years to a near “zero-growth” budget, despite the growing importance and complexity of telecommunications. This resulted in the late 1980s in severe budgetary pressure on the ITU’s resources in Geneva. Moreover it seemed at that time that Regional standardisation organisations such as ETSI would be able to work much faster and more effectively than the ITU and that the ITU’s world-wide leadership would be undermined.

This problem was tackled in three ways:

The ITU set up a high level committee to review the function, structure and organisation;

A voluntary group of experts was also set up to examine the Radio Regulations with a view to their simplification;

In 1990 the CCIR reviewed its working methods and adopted a two year cycle for studies, with permanent Working Parties, WPs, (for the regular studies) and Task Groups, TGs, ( for urgent studies) which would meet once or twice in the two year cycle, reporting to the Study Groups which now had a largely managerial function. A procedure for the rapid approval of Recommendations by correspondence was also agreed, so that Study Group output did not have to await the next Plenary Assembly. These arrangements worked well. They did however lead to an impression that the work had greatly expanded. Indeed some expansion has taken place due to the demand for Recommendations on new and developing services, such as for mobile satellite services, and on difficult sharing issues. In the main however the impression follows from the separate identification of Working Party and Task Group meetings whose activities were previously contained within the Study Group organisation.

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2.4 The new ITU

2.4.1 The new structure

At a special additional Plenipotentiary Conference held in 1993, the report of the High Level committee was considered and a new structure evolved for the ITU. The Plenipot. adopted a new Constitution and Convention. There will be a Plenipotentiary Conference at regular 4-yearly intervals (held in 1994 in Kyoto, in 1998 in Minneapolis and in 2002 in Marrakesh), and the ITU Council will supervise budgets and activities at its annual meetings.

The ITU now comprises a general secretariat, concerned with policy and strategic issues, and three Sectors for: - for Radiocommunication (ITU-R), - Telecommunication Standardization (ITU-T), and - Telecommunication Development (ITU-D). Each Sector has a Bureau which provides support facilities in Geneva and has a regular series of Conferences to plan and control the activities. Each Sector also has an Advisory Group, or Board, to study strategic and organisational matters within the Sector. These Advisory Groups hold joint meetings for matters of common or borderline interest.

The Standardization Sector has largely subsumed the CCITT. Standardisation is a key issue and some of the topics previously being studied within the CCIR have been transferred to the T Sector for further action. In particular, the CMTT joint study group has been transferred to the Standardization sector. The borderline between radio-spectrum issues and standardisation is not altogether clear-cut and some inter-sector coordination groups (ICGs) have been set up, e.g. on the use of ISDN over satellite paths.

The Development Sector incorporates the staff of the Bureau for Telecommunication Development, and has the task of seeking to promote effective telecommunications in developing countries. The D-Sector has established two study groups to deal with issues of concern for development. Endeavours are being made to ensure that the work in the various Sectors is complementary and does not duplicate work elsewhere.

2.4.2 The Radiocommunication Sector

However, the Radiocommunication Sector has undergone the most significant changes in the new structure. It now includes the staff of the CCIR secretariat and of the IFRB.

The components of the Sector are:

A series of World Radio Conferences (WRCs). The expectation was that a regular pattern of meetings with, it was hoped, more limited agendas, would enable improvements to the Radio Regulations to be made progressively, avoiding the major confrontational difficulties of past meetings when there seemed to be only a single opportunity to attempt to solve the problems on the agenda. The agendas for the next and next but one WRCs are formally set by the Council but the content will be identified by participants at previous WRCs. So far these expectations have not been altogether achieved. The pace of development of new radiocommunication systems, and the economic imperatives for obtaining secure frequency assignments before major long term investment, has meant that it has been difficult to limit the scope of each WRC and also difficult to identify topics which may be deferred to 4 years’ time rather than 2 years. The original scheme was that WRCs would be held at regular 2-yearly intervals, and WRCs were held in 1993, 1995, 1997, 2000 and 2003. But this pace could not be maintained, The pressures on time to undertake the necessary technical studies, to establish national requirements, to coordinate these as regional proposals and to seek to inform others of the technical and logical basis for the proposals were excessive. Moreover major budgetary problems emerged following the 2002 Plenipot. Accordingly the 2 yearly schedule has been relaxed, to 2½ years up to May 2000 in Istanbul, and 3 years to June 2003 in Geneva. The next WRC is currently scheduled for 2007 and it may be expected that this

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more flexible time scale will continue. Efforts continue to limit the agendas to essential and urgent matters but it is likely that future WRCs will continue to make very great demands.

Meetings of the Radiocommunication Assembly; again foreseen at regular 2-yearly intervals, but now following the more extended timing of WRCs.

Meetings of Radiocommunication Study Groups, and their associated WPs and TGs were envisaged to be on an approximate 2-yearly pattern.

These continue the new working methods of the CCIR Study Groups established in 1990, but these have subsequently been further streamlined.

The Radiocommunication Assembly has established of a Conference Preparatory Meeting (CPM) which prepares a report for the next WRC on technical and procedural matters. Most Study Groups are involved in preparing sections of the report.

The work of the CCIR Study Groups continued as Radiocommunication Study Groups, together with the review of all Questions with the intention of prioritising the work. The methods for preparation and approval of new and revised Recommendations by correspondence have been strengthened and streamlined, but with less opportunity for careful reassessment of content and wording, there is naturally an increased danger that more speed will mean less definitive Recommendations.

Currently the ITU-R Study Groups now comprise:

SG1 Spectrum managementSG3 Radiowave propagationSG4 Fixed-satellite serviceSG6 BroadcastingSG7 Science services (space research, radio astronomy, standard frequencies and time signals)SG8 Mobile, radiodetermination, amateur, and related satellite servicesSG9 Fixed service

2.5. The ITU Radio Regulations

2.5.1. Definitions

The starting point for international regulation has to be a common understanding of the key technical parameters.

The Radio Regulations contain agreed definitions for many aspects associated with spectrum management, ranging from agreed abbreviations for the designation of the modulation of emissions, to frequency tolerances, necessary bandwidth, terms for such things as radiated power and antenna gain, etc. The ITU also coordinates with the group responsible for the International Electrotechnical Vocabulary to ensure agreement, and thus a common understanding, of the definitions for a large number of the technical terms contained in the ITU-R Recommendations.

The main thrust of the Radio Regulations is to specify the frequency bands allocated specific radio services and to lay down the procedures for introducing new radio transmitters into the crowded frequency bands by a process of consultation and coordination.

2.5.2. Radiocommunication Services

Radio stations are classified into types of service. The Radio Regulations list about 42 types of service - many of them were defined specifically for consideration at a particular WARC/WRC.

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Definitions are given for each service. For example, two important services are the “fixed-satellite service” and the “fixed service” and they are defined as follows;-

RR 1.201. Fixed service; a radiocommunication service between specified fixed points.

RR 1.21. Fixed-satellite service; a radiocommunication service between earth stations at specified fixed points when one or more satellites are used; in some cases this service includes satellite-to-satellite links, which may also be effected in the inter-satellite service; the fixed-satellite service may also include feeder links for other space radiocommunication services.

The complete set of services may be grouped as shown in Figure 2. All the terrestrial services which are marked with an asterisk also have an equivalent satellite service (e.g. the fixed-satellite service corresponding to the fixed {i.e. terrestrial} service).

Figure 2Terrestrial Radiocommunication Services

(Those shown with an asterisk also have a corresponding satellite service)

In addition there are some services which only have a satellite context. These are listed in Figure 3.

Figure 3Satellite-only radiocommunication services

2.5.3. Designation of emissions

1 The ITU Radio Regulations comprise a number of Articles (or Chapters) and a series of Appendices. Each paragraph in the Articles is given a paragraph number, thus: RR 21. In this text the paragraph numbers will be identified just by the RR number.

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Terrestrial Services

Fixed* - - Aeronautical Mobile ( R )

- - - - - -Aeronautical Mobile* - - - - - Aeronautical Mobile (OR)*Mobile* - - - - ¦ - - - - - Land Mobile*

- - - - -- Maritime Mobile* - - - - - - - Ship Movement - - Port Operation

- - - Maritime Radionavigation*Radiodetermination*- - - Radionavigation* - - - - - - Aeronautical Radionavigation*

- - Radiolocation*

Broadcasting* Amateur* Radio Astronomy* Meteorological Aids Standard Frequency and Time Signal*

earth-exploration-satellitemeteorological-satelliteinter-satellitespace operationsspace research

The nature of an emission is specified in a designation. When expressed in full this usually comprises seven characters, of the form:

wxyzABC

- the first 4 characters give the necessary bandwidth- the next 3 characters give the classification according to the type of modulation- there may also be 2 additional final characters, providing some supplementary information.

The code for the necessary bandwidth comprises 3 digits giving the numerical value and a letter which indicates the multiplier, inserted in the position of the decimal point. Thus:

necessary bandwidth of 0.1 Hz = H100 2.4 kHz = 2K40

202 MHz = 202M 5.65 GHz = 5G65

The main three characters (ABC) give the classification, as set out in tables 3, 4, and 5:

Type of modulation, main carrier CodeAn unmodulated carrier NThe main carrier is amplitude-modulated Double-sideband A Single sideband, full carrier H Single sideband, reduced or variable level carrier R Single sideband, suppressed carrier J Independent sidebands B Vestigial sideband CThe main carrier is angle modulated Frequency modulation F Phase modulation GThe main carrier is amplitude and phase modulated, simultaneously or in a pre-established sequence

D

Pulse emissions a sequence of unmodulated pulses P Modulated in amplitude K Modulated in width/duration L Modulated in position/phase M With angle modulation of carrier during pulses Q Other pulse modulation methods or combinations of methods VHybrid modulation systems not covered above, involving two or more basic modulation techniques, amplitude angle or pulse

W

Other cases X

Table 4Classification of Emissions. 1: Type of modulation

Modulating Signal CodeNo modulating signal 0A single channel of quantized or digital information

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Without the use of a sub-carrier 1 with a sub-carrier 2A single channel containing analogue information 3Two or more channels containing quantified or digital information 7Two or more channels containing analogue information 8A composite system containing both analogue and digital channels 9Other cases X

Table 5Classification of emissions, 2: Nature of modulating signal

Type of Information Transmitted CodeNo information transmitted NTelegraphy - for aural reception ATelegraphy - for automatic reception BFacsimile CData transmission, telemetry, telecommand DTelephony (including sound broadcasting) ETelevision FCombinations of the above WOther cases X

Table 6Classification of emissions, 3: Type of Information

2.5.4 Other technical parameters

The Regulations also contain definitions for antenna gain and radiated power, for spurious emission levels and for frequency tolerance, etc. Although some recommendations may recommend tighter limits for some of these levels and parameters, the Regulations give an internationally agreed minimum level.

2.5.5. Bandwidth Definitions

There are three definitions for bandwidth used in the Radio Regulations. These are illustrated in Figure 6

The necessary bandwidth, for a given class of emission, is the width of the frequency band which is just sufficient to ensure the transmission of information at the rate and the quality required under specified conditions. The Radio Regulations give a number of empirical rules for its determination.

The assigned frequency band is determined by adding the necessary bandwidth to twice the frequency tolerance

The occupied bandwidth is defined as the width of the frequency band such that, below the lower and above the upper frequency limits, the mean powers emitted are each equal to a specified percentage (usually 0.5%) of the total mean power of the emission. This definition takes account of the practical effects of out of band emissions.

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Figure 6Sketches to illustrate terms used in describing features of the spectrum of emissions

a) carrier on-off keyedb) SSB telephony reduced carrier emission

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2.5.6. Frequency Allocations

The radio frequency spectrum from 9 kHz to 275 GHz is divided into bands which are allocated for the use of stations of the various radiocommunication services. Some allocations are also specified in the band between 275 and 400 GHz. These allocations are to be found in the ITU Table of Frequency Allocations in Article 5 of the Radio Regulations. Below is an abstract from the Table covering 156.8375 to 235 MHz which illustrates well many aspects of the Table.

156.7625-156.8375 MARITIME MOBILE (distress and calling)5.111 5.226

156.8375-174FIXEDMOBILE except aeronautical

mobile

156.8375-174FIXEDMOBILE

5.226 5.229 5.226 5.230 5.231 5.232174-223BROADCASTING

174-216BROADCASTINGFixedMobile5.234

174-223FIXEDMOBILEBROADCASTING

216-220FIXEDMARITIME MOBILERadiolocation S5.2415.242

5.235 5.237 5.243 220-225 5.233 5.238 5.240 5.245

223-230BROADCASTINGFixedMobile

AMATEURFIXEDMOBILERadiolocation 5.241

223-230FIXEDMOBILEBROADCASTING

225-235FIXEDMOBILE

AERONAUTICALRADIONAVIGATION

Radiolocation

5.243 5.246 5.247 5.250230-235FIXEDMOBILE

230-235FIXEDMOBILEAERONAUTICAL

RADIONAVIGATION5.247 5.251 5.252 5.250

Note in particular;-

There is a differing pattern of allocations in the three ITU Regions.

some frequency bands are allocated to one service only (an exclusive allocation) but many are allocated to two services or more (a shared allocation).

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allocations may have Primary or Secondary status. Primary allocations are printed in capital letters and Secondary allocations are in lower case. A transmitting station operating in a band in which its service has a secondary allocation may not cause significant interference to a station whose service has a primary allocation, and a receiving station of a secondary service has no grounds for complaint if a station of a service with a primary allocation interferes with its reception. The control of interference between stations of services with allocations of equal status is discussed below.

There are hundreds of numbered footnotes to the Table, most of which extend or vary the allocations given in the Table; usually these footnotes vary the allocation for application to particular countries.

For example, footnote 5.235 states:

5.235 Additional allocation:  in Germany, Austria, Belgium, Denmark, Spain, Finland, France, Israel, Italy, Liechtenstein, Malta, Monaco, Norway, the Netherlands, the United Kingdom, Sweden and Switzerland, the band 174-223 MHz is also allocated to the land mobile service on a primary basis. However, the stations of the land mobile service shall not cause harmful interference to, or claim protection from, broadcasting stations, existing or planned, in countries other than those listed in this footnote.

This footnote permits the UK to use the band between 174 -223 MHz for mobile services instead of broadcasting. Such national departures from the international allocations are not merely a public declaration of how a country intends to use a band; these variations have been agreed internationally. Quite apart from these footnotes, each country is free to use a band as it chooses provided that its action does not cause regulatory trouble to other countries and provided that it is prepared to suffer whatever consequences may arise from different practices elsewhere.

2.5.6. Frequency Assignments

National frequency authorities assign specific carrier frequencies, within the frequency block allocations, for transmission at radio stations; the assignments being made for specified purposes, usually specifying some of the parameters of the emission, such as the receiving point, the carrier power, the bandwidth, some antenna characteristics etc. A frequency assignment will have been chosen within an appropriately allocated band. For most services the authority will make sure that it does not assign the frequency to two stations if they are likely to interfere with one another. If interference problems do arise between two stations within the jurisdiction of the same national authority, it is the authority’s responsibility to resolve the problem.

. Two basic methods are used to control this international interference.

In some cases in the past, World Administrative Radio Conferences (WARCs) or, regional conferences, have drawn up plans of frequency assignments for specific radio services in specific allocated bands. Ideally such plans include all the requirements that each country concerned expects to have for the following 10 or 20 years, up to the time of a possible future planning conference. These are often called “a priori” plans. If complete satisfaction of all requirements is not feasible without foreseeable interference when all the assignments are in use, some way is sought for scaling down requirements, or relaxing the technical criteria, so as to reach a compromise solution. If a plan can be agreed, each national authority then assigns frequencies from the plan to the stations of its country as they are needed. At the present time most broadcasting and some mobile services are planned, including satellite broadcasting and some satellite fixed services (the allotment bands).

Most other services are regulated by the priority of registration of the assignment. Assignments are made in accordance with procedures for coordination between stations which may potentially interfere with each other, by specifications for power flux density or antenna gain, or through other agreements.

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3.0 REGIONAL AND NATIONAL SPECTRUM MANAGEMENT

3.1 Introduction

As indicated earlier, the ITU is the pre-eminent body for agreements on the management of and strategy for the use of the radio spectrum. However, each national administration is ultimately sovereign in the decisions it makes on spectrum usage, even though they have agreed to accept the conclusions of international agreements as set out in the treaty document, the Radio Regulations.

Nevertheless, there is a considerable interest in the harmonisation of spectrum usage and ofequipment specification at a Regional level, and this has had a considerable impact on thespeed with which decisions and Recommendations are made or updated. In Europe this drivetowards harmonisation is stimulated by the need to remove barriers to trade which might byimposed by differing specifications or differing frequency assignments in various countries.The countries within the European Union have an imperative towards a common market andin some circumstances European Directives are established to ensure this common basis forstandards.

At the European level, telecommunication equipment standards and specifications areprepared by the European Telecommunication Standards Institute (ETSI), and radioregulatory and spectrum matters are dealt with within the Electronic Communication Committee (ECC) of the European Conference of Postal and Telecommunications Administrations (CEPT). Other Regional bodies such as the European Broadcasting Union (EBU) undertake some voluntary aspects of radio regulation for their own services.

Nationally, in the United Kingdom civil radio regulation is the function of the Office of Communications (OFCOM). This is a new body establishes at the end of 2003. OFCOM has stated oits intention to regulate with a light touch, as far as possible opening up spectrum management to the control of market forces. Until that time the function was undertaken by the Radiocommunications Agency, an executive agency of the DTI.

3.2. The Electronic Communication Committee (ECC)

3.2.1. European Conference of Postal & Telecommunications Administrations (CEPT)

The CEPT was established in 1959 by 19 countries and expanded to 26 during its first ten years. The original members were the incumbent monopoly-holding postal and telecommunications administrations and the CEPT's activities included co-operation on commercial, operational, regulatory and technical standardisation issues.

In 1988 CEPT decided to create ETSI, The European Telecommunications Standards Institute, into which all its telecommunication standardisation activities were transferred.

In 1992 the postal and telecommunications operators created their own organisations, PostEurope and ETNO respectively. In conjunction with the European policy of separating postal and telecommunications operations from policy-making and regulatory functions, CEPT thus became a body of policy-makers and regulators. At the same time, Central and Eastern European Countries became eligible for membership in CEPT.

The CEPT now has 45 members covering almost the entire geographical area of Europe: Albania, Andorra, Austria, Azerbaijan, Belgium, Bosnia and Herzegovina, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, United Kingdom of Great Britain and Northern Ireland, Greece, Hungary, Iceland, Ireland, Italy, Latvia,

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Liechtenstein, Lithuania, Luxembourg, Malta, Moldova, Monaco, Netherlands, Norway, Poland, Portugal, Rep of Macedonia, Romania, Russian Federation, San Marino, Serbia and Montenegro, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey, Ukraine, Vatican.

The role and purpose of CEPT was redefined in 1995 as follows:

establishing a European forum for discussions on sovereign and regulatory issues in the field of post and telecommunications issues;

providing mutual assistance among members with regard to the settlement of sovereign/regulatory issues;

exerting an influence on the goals and priorities in the field of European Post and Telecommunications through common positions;

shaping, in the field of European posts and telecoms, those areas coming under its responsibilities;

carrying out its activities at a pan- European level;

strengthening and fostering more intensively co-operation with Eastern and Central European countries;

promoting and facilitating relations between European regulators (e.g. through personal contacts); influencing, through common positions, developments within ITU and UPU in accordance with European goals;

responding to new circumstances in a non-bureaucratic and cost-effective way and carrying out its activities in the time allocated;

settling common problems at committee level, through close collaboration between its committees;

giving its activities more binding force, if required, than in the past; creating a single Europe on posts and telecommunications sectors.

The CEPT now deals exclusively with sovereign/regulatory matters, and now has established two committees, one on postal matters, the CERP (Comité européen des régulateurs postaux) and one on telecommunications issues: the ECC (Electronic Communication Committee).

The committees handle harmonisation activities within their respective fields of responsibility, and adopt recommendations and decisions. Such recommendations and decisions normally prepared by their working groups and project teams.

In 1991, the European Radiocommunications Committee established a permanent office in Copenhagen, the European Radiocommunications Office - ERO - with the purpose to support the activities of the committee and to conduct studies for it and for the European Commission.

3.2.2. The Electronic Communication Committee (ECC)

The ECC is the Committee which brings together the radio regulatory administrations of the CEPT member countries. Counsellors from the European Commission and the European Free Trade Association participate in the activities of the ERC and its Working Groups.

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Representatives of relevant intergovernmental organisations as well as other organisations or administrations concerned with European telecommunications may be invited by the Chairmen of the ECC or its Working Groups to participate as observers in meetings, on an ad-hoc basis.Individual members of the European Telecommunications Standards Institute (ETSI) may participate in Project Teams established by the Spectrum Engineering Working Group.

The European Radiocommunications Office supports the work of the ECC, the Steering Group and all of its Working Groups. It provides a focal point for consultation and undertakes studies on the use of the radio spectrum and on the harmonisation of spectrum for new systems.

3.2.3. Tasks of the ECC

The main task of the ECC is to develop telecommunications policies and to coordinate frequency, regulatory and technical matters in this field. Another important task is the development of guidelines in preparation for ITU activities and conferences.

The proposals for harmonisation measures are prepared by the working groups of the ECC generally in the form of draft Decisions, Recommendations or Reports which are given final approval following consultation with various interested parties (operators, manufacturers, users and standards bodies, etc.).Because radio regulatory matters increasingly require firm agreements on a pan-European basis to facilitate the efficient use of the radio frequency spectrum, the instrument of ECC Decisions was established. These Decisions are binding agreements between the administrations and can therefore play a major role in the harmonisation of radio regulatory regimes within the CEPT countries.

3.2.4. ECC Structure

The ECC has six permanent Working Groups. Both the ECC and the Working Groups may create Project Teams to work to well defined tasks and limited time periods. The Working Groups are:

Working Group FM (Frequency Management)

Working Group RA (Regulatory Affairs)

Working Group SE (Spectrum Engineering)

Conference Preparatory Group (CPG) - which coordinates the preparations for ITU World Radio Conferences (WRCs) and Radio Assemblies

Working Group IA (Interconnection and access)

Working Group NNA (numbering, naming and addressing)

In addition, task groups can be established for well defined tasks.

3.2.5. ECC Policy

Some years ago a comprehensive set of policy goals were adopted so far as radiocommunication aspects are concerned. These continue to define areas of activity within the ECC:

To forward plan and harmonise the efficient use of the radio spectrum in Europe so as to satisfy future demand in the most efficient manner, consistent with quality of service requirements and other commercial considerations, including orderly transfer and the reorganisation or closing down of existing systems, when necessary;

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harmonise the use of frequencies within Europe and foster a world-wide harmonisation of the use of frequencies with the aim of ensuring effective utilisation, minimum interference and the safety of human life and property;

ensure that European telecommunications standards for radio equipment and systems utilise the radio spectrum efficiently, taking into consideration commercial and market requirements and the needs of all users of radio, and the harmonised introduction of these standards within the national type approval regimes of CEPT countries;

provide for the free circulation of radiocommunications equipment within the CEPT countries;

provide for the mutual recognition of type approval certificates for equipment operating in harmonised frequency bands and type approval based on mutual acceptance of test reports for other equipment;

provide for the mutual recognition of radio licences within CEPT;

approximate administrative procedures with respect to free circulation and the use of radio equipment applied by members individually or in co-operation;

exchange information in order to avoid unnecessary duplication of effort in the national research activities of Members;

exchange information on national legislation with a view to facilitating harmonisation in the field of radio;

exchange information on the principles of financing the work of the administrations with a view to finding a common basis for fees to be collected from users, manufactures, importers, or the sale of radio equipment;

encourage a policy of deregulation where possible and appropriate, and in a way which minimises burdens on operators, manufacturers and users;

take appropriate measures to achieve greater economy, efficiency and quality in the work of the ECC and its constituent bodies;

co-ordinate Members’ actions with respect to EC initiatives;

foster the development of European Common Proposals (ECPs) and co-ordinate members’ submissions and participation in conferences and meetings of the International Telecommunication Union (ITU);

consult widely with all relevant players.

3.2.6. The European Radiocommunications Office

Because of the size and scope of the activities of the ECC in its role to determine and harmonise, where appropriate future developments in regulatory and frequency management issues, the need for permanent staff resources led to the creation in May 1991 of the European Radiocommunications Office (ERO) which is located in Copenhagen, Denmark. There was also a similar office dealing with telecommunications (ETO). However the ETO has since been subsumed within the ERO.

3.2.7. Detailed Spectrum Investigations (DSI)

These consider the current and future use of the frequency spectrum below 105 GHz. The study has been undertaken in several stages, dealing with different parts of the spectrum.

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3.2.8. Working Group SE and its project teams

As an example of the way in which the work is organized, the terms of reference of WGSE are to:

develop technical guidelines for the use of the frequency spectrum by various radiocommunication services;

develop sharing criteria between radiocommunication services, systems or applications using the same frequency bands;

develop compatibility criteria between radiocommunication services using different frequency bands;

co-ordinate related activities and contributions for the work in ITU-R;

co-operate with relevant technical bodies in ETSI in accordance with the procedures given in the Memorandum of Understanding between ECC and ETSI;

study technical impacts of ISM and other non-radio equipment on radio services taking into account related activities in the relevant International and European Organisations;

contribute to the CPG, where appropriate, on the preparation of CEPT positions for WRCs and other relevant fora;

seek, where relevant, contributions and assistance from the ERO and the relevant ECC subordinate bodies;

consult with various bodies and organisations within CEPT countries or Administrations outside the CEPT, with the principal aim to collect information and to broaden the support for the deliverables of the working group;

prepare draft Decisions as directed by the Plenary and prepare and approve Recommendations and Reports as necessary

3.2.9. consultation

To assist in the consultation process and to provide general customer information about the work of the ECC and its Working Groups, the ERO publishes a regular newsletter which contains news about the activities and the decisions of the ECC. The ERO also provides detailed customer information about the ongoing work of the ECC via the ERO Internet at http/www.ero.dk. The ERO Internet is an important element in the consultation process where consultative texts are provided as well as information about the latest developments within the ECC with reports of recent meetings and approved texts of ECC Decisions, Recommendations and Reports and information on their implementation by the CEPT administrations.

3.3. The European Telecommunications Standards Institute (ETSI)

ETSI is a comparatively recently established body, now 15 years old, and has grown rapidly as a consequence of the need to have European standards for equipment and systems. The membership comprises both administrations and industrial members. It has facilities at its headquarters in Sophia Antipolis in the South of France. Its members include administrations, network operators, manufacturers, service providers, research bodies and users. It currently has 786 members from 56 countries.

The ETSI organisation is headed by the General Assembly and has a number of technical committees (TC), ETSI Projects (EP) and partnerships and other groups. The terms of reference of ETSI include all

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aspects of telecommunication equipment standardisation. So far as radio aspects are concerned, the main activities are:

TC ERM (EMC and radio spectrum matters)TC MSG (mobile standards group)TC PLT (power line telecommunications)TC SES (satellite earth stations and systems)JTC broadcast (joint group EBU/CENELEC/ETSI on broadcasting)The project activities include:EP BRAN (broadband radio access networks)EP DECT (digital enhanced cordless telecommunications), EP TETRA (terrestrial trunked radio),

There is also a group of partnership projects concerned with 3GPP, third generation mobile radio.There is clearly an overlap of interest in some of the parameters which require to be standardised. Matters concerned with radiated power, spurious emissions, frequency channelisation, etc., are of importance to manufacturers and so need to be included in equipment specifications. However there is an impact of these parameters on spectrum utilisation, which is the responsibility of the CEPT/ECC. This has been resolved by a memorandum of understanding (MoU) between the two organisations so that for the key spectrum management parameters there is a process for consultation and coordination between the two bodies.

ETSI deliverables are defined as follows:

European Standard, (EN) (telecommunication series) which contains normative provisions approved for publication by a process involving national standards organisations or ETSI national delegations;

ETSI Technical specification (TS) which contains normative provisions approved by a technical body;

ETSI Standard (ES) which contains normative provisions approved by the membership;

ETSI Technical Report (SR) a special report containing information approved by a technical body;

3.4. UK regulation - OFCOM

Within the UK, the body currently responsible for administering radio regulation and managing the spectrum is OFCOM. Other countries have established agencies or organizations, and the precise scope of each body depends on the national legislation and decisions. Except perhaps in New Zealand, no other country has gone as far as the UK in restricting its activities to current priorities and making arrangements to permit market forces to determine the use of radio in the immediate future.

In June 2003 the Communication Act 2003 received Royal assent. This finally confirmed the arrangements for the establishment of the Office of Communications, OFCOM.

OFCOM brings into one non-governmental regulatory organisation five existing bodies:Broadcast Standards CommissionIndependent Television CommissionRadio AuthorityOFTEL (Office of Telecommunications)Radiocommunciations Agency

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In some ways, OFCOM takes on the responsibilities inherited from these organisations, as well as additional functions intended to ensure that commercial television and radio, telecommunication networks and wireless and satellite services operate, compete and develop in the greater public interest.

It seems so far that the structure and staffing levels of OFCOM will greatly hamper the proper management of the radio spectrum. With the predominant interests in the non-technical regulation of broadcasting content, it is not at all clear that the technical considerations of maximising the effective use of our scarce resource of the radio spectrum are being appreciated. Moreover early presentations of the role of OFCOM have emphasised the need for competition above everything else. This too does not auger well for the health of spectrum management.

The stated objectives of OFCOM are:

“OFCOM is the regulator for the UK communications industries, with responsibilities across television, radio, telecommunications and wireless communications services.

OFCOM exists to further the interests of citizen-consumers as the communications industries enter the digital age.

To do this OFCOM shall:

Balance the promotion of choice and competition with the duty to foster plurality, informed citizenship, protect viewers, listeners and customers and promote cultural diversity.

Serve the interests of the citizen-consumer as the communications industry enters the digital age.

Support the need for innovators, creators and investors to flourish within markets driven by full and fair competition between all providers.

Encourage the evolution of electronic media and communications networks to the greater benefit of all who live in the United Kingdom.”

It is important to note that nowhere amongst these aims are any technical objectives to ensure the effective or efficient use of the spectrum, nor to provide any leadership in guiding UK interests towards the establishment of common developments which will maintain the UK as leaders in the future uses of radio and the benefit of the UK economy as a whole.

It will be of great interest and concern to see how OFCOM actually undertakes its tasks into the future. Announcements may be found on the web site www.ofcom.org.uk

Nevertheless, OFCOM has inherited some of the obligations and functions of the Radiocommunications Agency. For example:

Frequencies for civil applications are assigned by arrangements made by OFCOM; in some cases the responsibility for assignments in a particular allocated band is passed to a user or a user group. For some low power applications individual licences are not required for type approved equipment.

OFCOM is also responsible for preparing for and leading international work both within Europe and in the ITU for radio matters. Other telecommunication aspects are the responsibility of the DTI.OFCOM currently organises the UK ITU-R Consultative Committee. This committee arranges for national study groups which essentially mirror the international ITU-R organisation, with additional working parties for some ETSI and ERC (SE) aspects. There are also other briefing arrangements for preparing the UK position for WRC and other CEPT matters. Recent decisions to limit UK work and leadership in such activities raises considerable uncertainty as to the future place of the UK as a prominent and influential participant in the work. It seems likely that looking ahead to determine future effective uses of the spectrum, and leading UK industry and users towards systems and networks which will co-exist efficiently, will not take place and the future is very uncertain.

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3.5 The Framework set in place by The Radiocommunications Agency

Much of the current basis for spectrum management in the UK was set in place by the Radiocommunications Agency and its predecessors. Through the 1980s and 90s, the Agency adopted the approach of close consultation with users and industry, responding vigorously to the requirement to respond to the need of its "customers".

In 1994 it produced a Vision statement which included a commitment:"We will publish, and update annually, a strategic plan for the use and development of the radio spectrum.""We are also committed to improving communications ...... by publishing more information about spectrum usage......"The second commitment was met by the availability from the Agency library of a large number of information sheets, which include much information on spectrum use which, in the past would have been considered restricted to officials.

3.5.1. The Wireless Telegraphy Act

The objectives for the Agency were developed within the framework of the Wireless Telegraphy Act 1998, prior to this the way the RA worked was constrained by the 1949 Act which did not permit a proactive spectrum management style. The limitations were recognised in 1994, when the Agency issued a "Green Paper", a consultative document on the way in which spectrum management in the UK should be undertaken in the future.

This green paper reviewed the way in which the spectrum is currently managed and asked for views on:

- the way in which the spectrum should be managed - should it be undertaken by commercial spectrum management organisations or should it be a government function- open access to databases - spectrum pricing - should this be by administrative pricing /licensing provisions which would allow the cost of using crowded parts of the spectrum to be increased – should there be rights of ownership of parts of the spectrum, with the consequent trading in spectrum property - should there be auctions- how should enforcement of spectrum use be handled.

This consultation was with the background of some moves towards privatising and auctioning the spectrum in various countries; the annex to this section is a 1997 information paper on the situation in the USA.

The result of this consultation were published and there was a reasonably consistent view. The Agency should continue to manage the spectrum. It was recognised that some price incentive would be necessary to promote spectrum change, but this should mainly be done by administrative pricing with auctions as a possibility only for very special cases. The additional revenue created by this pricing policy should not be regarded as a tax but should be ploughed back into spectrum re-engineering and into research.

As a result of the consultation in this green paper a white paper was published in June 1996. This was called "spectrum management into the 21st century" and it was regarded as a "white paper with green edges" as it continued to indicate some options on which further consultation was sought. The proposals were largely in line with the dominant view of the industry and users. This white paper was being prepared for future legislation but the provision of parliamentary time was very uncertain. The "Wireless Telegraphy (spectrum management) Act was adopted as one of the early tasks of the present government.

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The 1988 Act is very short and continues to leave much of the detail for decision by the Secretary of State or by Statutory Instrument. The Act does permit administrative pricing, so that licences may be more expensive for both fixed and mobile stations in the south east of England. It also allows for auctioning of some parts of the spectrum.

The income resulting from these arrangements exceeds the expenditure of the Agency. The Act notes that some of this income may be used for relevant research, or if the case is argued some could be used to facilitate the necessary spectrum re-engineering. A large surplus is nevertheless returned to the Treasury.

3.5.2. Function

The Agency planned and managed spectrum use to ensure as far as possible that appropriate spectrum is available for those who need it when they need it, and that it is used efficiently and with as little interference as possible. In reaching decisions on the allocation and assignment of frequencies the Agency has to take into account the often competing requirements of radio users, and the use of the spectrum in other countries.

This is achieved by:

Frequency planning: Allocating different parts of the spectrum to particular services on a strategic basis so that the services do not interfere with each other;Careful planning and co-ordination with neighbouring countries are essential. This constrains the use of the spectrum. However, it also provides opportunities for UK businesses and users. There is a growing trend within Europe and on a more global basis to harmonise the use of radio wherever possible. This means agreeing that frequencies are used for similar applications in neighbouring countries and that, where appropriate, European standards and specifications are set for the approval of radio equipment. Harmonisation, particularly within Europe, benefits the UK in that it eases and speeds co-ordination between radio administrations, creates a wider and more open market for our manufacturers and, through increased competition, provides a wider choice of equipment and services. The management of the spectrum must be based on international agreements. The Agency played a key role, participating in many international negotiations to protect and promote the best interests of the UK.

Assignment and licensing: Planning the assignments made to individual users within the allocations and licensing systems so that spectrum is used efficiently without interference between users;

Since radio equipment has the potential to cause interference to other users of the spectrum, users of such equipment must obtain a Wireless Telegraphy Act (WT Act) licence. It is an offence to install and use radio transmission equipment without a licence unless it has been exempted from licensing.

Wherever possible the Agency aimed to exempt the use of the radio spectrum from licensing so as to reduce the burden on users. Many short range devices such as metal detectors, radio controls for model aircraft and some types of radio microphones are unlikely to cause interference to other users. Therefore they have been exempted from the requirement for a WT Act licence. The Agency made balanced use of the range of spectrum management tools at its disposal

Keeping the spectrum free: If harmful interference occurs, investigating and taking action to deal with it.

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3.5.2.1. Regulation The imposition of licence terms and conditions to enable users to operate without causing serious interference to each other, for example on the frequencies that may be used, the technical standards to be met by equipment and operating conditions;

3.5.2.2 Spectrum pricing Licence fees are set by regulation with a view to supporting spectrum management objectives, such as meeting demand for spectrum and the promotion of spectrum efficiency, economic benefits, innovation and competition. Users are, generally speaking, charged more if they have more extensive spectrum coverage or use radio in parts of the country where there is spectrum congestion. This helps ensure that, where spectrum is in short supply, it is used by those who can use it to best advantage;

3.5.2.3. AuctionsLicences may be auctioned where this is considered to promote optimal use of the spectrum. Generally speaking, licences would be auctioned only for new national or regional services and where there are more potential users than can be accommodated in the spectrum that is available;

3.5.2.4. Spectrum efficiency grants Subject to the consent of the Treasury, the Agency had power to make grants to promote spectrum efficiency.

The Agency took great care in all aspects of planning and assigning frequencies to users, taking account not only of the type and location of the proposed use but, most importantly, of other existing or planned users of the spectrum. However interference may still occur to radio transmissions. Sources of interference can include other legitimate radio transmitters which may be malfunctioning, incorrectly installed or improperly operated, unauthorised broadcasters or non-radio equipment.

Staff at the Agency's network of local offices offered customers advice about radio services and investigated complaints of interference. If necessary, they use their statutory enforcement powers to remove or reduce interference.

3.5.3. Radiocommunications Agency Strategy

Versions of the Agency's strategy document highlighted some key issues:

3.5.3.1 AimsThe Agency was responsible for managing most non-military radio spectrum in the UK and representing the UK in international discussions on radio spectrum. It aimed to develop its role at the centre of one of the most dynamic sectors of the economy.

The Agency's fundamental aim was to excel as a world-class spectrum manager in support of the Government's aims. Key elements of its strategy for achieving this include:

Supporting Government policies on competitiveness and the knowledge driven economy through effective management of the radio spectrum, including licensing spectrum for Third Generation mobile telecommunications at 2 GHz and Interactive Multimedia Services at 40GHz;

Implementing administrative spectrum pricing for all sectors and providing systematic assessments of the economic value of the spectrum in order to review licence fees on a regular basis;

Introducing spectrum trading, subject to Ministers' decisions and changes to EU and UK law; This is now being progressed in OFCOM.

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Implementing new information systems to cope with future spectrum management needs, improve business processes and enhance electronic access;

Benchmarking the Agency's international standing as a spectrum manager;

Maximising the value of international involvement and contacts.

3.5.3.2. Objectives

Its broad objectives may be summarised as follows.

1/ To support Departmental objectives by managing spectrum in accordance with a clear strategic plan, which:

promotes enterprise, innovation and competitiveness; and makes full and appropriate use of all available spectrum management tools, including regulation, administrative spectrum pricing and, where suitable, auctions; and by carrying forward innovative and progressive approaches to spectrum management.

2/ To improve the Agency's business processes and operations in order to: provide a better service to customers, where appropriate through the devolution of

spectrum assignment services to local offices; and make full use of quality assurance techniques to enhance quality of service.

3/ Successfully to implement, and make the most of the opportunities provided by, the public-private partnership Radio Spectrum International (RSI) to acquire fully integrated modern information systems that meet the Agency's business requirements and enable it better to: satisfy customers' needs; plan and manage spectrum effectively; and continue to improve efficiency.

4/ To seek improvement in global and regional spectrum management co-ordination to the benefit of the UK; and, through RSI to exploit commercially the Agency's reputation and expertise through the provision of international consultancy services.

5/ To promote a programme of contracted research to underpin developments in the utilisation of the radio spectrum.

6/ To ensure compliance with spectrum management requirements imposed for the benefit of all radio users in order to keep the spectrum clear of undue interference, through: enforcement; interference investigation and resolution; and spectrum monitoring; and to develop policies to achieve these objectives.

7/ To ensure the efficiency, effectiveness and integrity of the Agency's business processes, through corporate planning; financial and management accounts; efficient execution and recording of money transactions; and the application of resource management disciplines.

8/ To be a caring and considerate Investor in People and to develop the skills of the Agency's staff and unleash their creativity and talents to further Agency objectives; enhance quality of service; maintain the Agency's key role as strategic managers of the spectrum; and uphold its reputation for excellence, integrity, independence and impartiality.

3.5.3.3. Strategic Spectrum PlanningStrategic planning is at the heart of successful spectrum management. In the spirit of Open Government, the Agency regularly published its Spectrum Strategy for customers' information and to obtain feedback. This presented a broad overview of the whole range of spectrum uses, both civil and military, and identified important future developments both in the UK and internationally. It also gave

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summaries of market forecasts of future demand for public mobile communications, private business radio and fixed links.

3.5.3.4 Innovation in Spectrum ManagementThe Agency continued the process of updating its business processes and refining its range of licence and licence-exempt products. It also started using the new spectrum management tools provided by the Wireless Telegraphy Act 1998 to help meet increasing demand for spectrum, encourage spectrum efficiency and promote innovation and competition.

3.5.3.5. Administrative Spectrum PricingThe first stage of implementation commenced in July 1998 and tackled the worst distortions of the previous pricing regime. A new licence class was introduced for on-site private business radio with significant fee reductions for thousands of small businesses. At the same time, a first step was taken to increase fees for cellular mobile telephony. This started to bring licence fees for large and small business users of mobile radio more into balance on a pro rata basis.

Major preparatory work for the second stage of spectrum pricing implementation continued throughout the year. A consultative document was issued in September 1998 which contained proposals for continuing the re-balancing mentioned above and the extension of spectrum pricing principles to other mobile radio and point-to-point fixed links, the areas where spectrum pressures are greatest. The proposals increase licence fees for those requiring exclusive and congested assignments while encouraging those willing to use uncongested spectrum or invest in more spectrum-efficient technology. Thousands of smaller business users would benefit from fee reductions.

3.5.3.6. Spectrum Auction for 'Third Generation' Mobile TelecommunicationsThe Agency, in consultation with industry, continued to develop plans for an auction of Third Generation mobile telecommunications operators’ licences. First Generation mobile telephone networks provided simple analogue voice telephony. Second Generation added data services like fax and e-mail to basic voice service, with higher rate data capabilities expected over the next few years. Third Generation should be capable of providing much higher data rates, in addition to conventional voice, fax and data services. This offers the prospect of high-resolution video and multimedia services on the move, such as mobile office services, virtual banking and on-line billing, home shopping, video conferencing, on-line entertainment and Internet access.

Experience overseas has shown that the traditional licensing method of comparative selection or 'beauty contests' tends to favour incumbent operators. By contrast, auctions are a fast, transparent, fair and economically efficient way of allocating the scarce resource of radio spectrum. In May 1998, Barbara Roche MP, then Telecommunications Minister, announced to Parliament the objectives for the auction: to utilise the spectrum in the most efficient way; to promote effective and sustainable competition; and, subject to those objectives, to realise the full economic value of the spectrum to consumers, industry and the taxpayer.

In February 1999, the Telecommunications Minister announced 2 measures to encourage a new entrant to the mobile telecommunications market. These were, first, that the Government would mandate roaming to enable customers of a new operator access to existing networks nationwide, while the new entrant rolled out its own network. Second, that five licences would be auctioned, one more than the existing number of operators, with the largest licence reserved for a new entrant.

The auction took place in March and April 2000 and raised over 22 billion pounds. 4. SATELLITE SERVICES

4.1 THE FIXED SATELLITE SERVICE (FSS)

4.1.1 International frequency allocations for the FSS

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The following represents fairly accurately the way in which the FSS allocations in the international Table of Frequency Allocations have developed, but there are many minor Regional and national variations.

WARC-59, less than two years after the launch of the first scientific satellite, took note of the prospects of space radio services. It defined a few terms but made no significant frequency allocations. The early experimental satellites such as Telstar and Relay operated in bands near 2, 4 and 6 GHz on a non-interference basis.

WARC-63, held specially to provide for the newly developing space services, made the following allocations for the FSS, all primary:

3400 - 4200 MHz (down-links) [i.e. space to Earth]4400 - 4700 MHz (up-links)5725 - 6425 MHz (up-links)7250 - 7750 MHz (down-links)7900 - 8400 MHz (up-links)

WARC-71 added the following allocations for FSS at higher frequencies:

10.95 - 11.2 GHz (down-links) 11.45 - 11.7 GHz (down-links) 11.7 - 12.2 GHz (down-links) (Region 2 only)

12.5 - 12.75 GHz (down-links) (Region 1 only) 14.0 - 14.5 GHz (up-links)

17.7 - 21.2 GHz (down-links) 27.5 - 31.0 GHz (up-links)

plus several pairs of bands between 35 and 275 GHz and narrow bands at 2.6 GHz.

WARC-79 made complicated changes to most of the allocations then existing, and there were further changes at WARC-ORB-88. The result, currently in force, is approximately as follows, as far as Region 1 is concerned, all in GHz;- down-links up-links

5.15 - 5.25 3.4 - 4.2 and 4.5 - 4.8 5.725 - 7.075

7.25 - 7.75 7.9 - 8.4 10.7 - 11.7 12.5 - 13.25 12.5 - 12.75 12.75 - 13.25

15.43 - 15.63 17.3 - 17.7

17.7 - 21.2 27.5 - 31.0 37.5 - 40.5 42.5 - 43.5

47.2 - 50.2 50.4 - 51.4

plus several pairs of bands at higher frequencies.

As discussed later, allocations for the Fixed Satellite Service include bands used for feeder links for the broadcast and mobile satellite services.

Almost all of these bands are shared with the terrestrial fixed and mobile services and elaborate means are used to enable each service to use the spectrum as if the other service was not present. These means are discussed later in these notes. However the means that are used have serious disadvantages for both services, and especially for small-dish satellite systems. To counter this problem, countries in Europe and North America have co-operated to keep some bands free, in whole or in part, from terrestrial

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services, in order that they may be used more freely for small-dish systems. It may also be possible to use parts of the bands 19.7 - 21.0 and 29.5 -31.0 GHz in this way, but these bands are now coming under considerable pressure.

4.2. The Mobile-Satellite Services In General.

4.2.1. Definitions of basic regulatory terms.

The mobile-satellite services derive their terminology, to some extent, from that used for the terrestrial mobile services. RR 1.24 defines the mobile service as “a radiocommunication service between mobile and land stations, or between mobile stations”. RR 1.67 defines a mobile station as “a station in the mobile service intended to be used while in motion or during halts at unspecified points”. RR 1.69 defines a land station as “a station in the mobile service not intended to be used while in motion”. Two important points to be noted from these definitions are;

(a) Stations which are not themselves mobile but are used to communicate directly with mobilestations are within the mobile service and use frequency bands allocated to that service. The general term for these stations is “land station” but specific terms are also used, depending m the nature of the mobile stations involved (see below).

(b) The word “unspecified” in RR 1.67 is important; a radio station which is on wheels androadworthy but is only operated while it is stationary at one or more specified points may be, for regulatory purposes, a fixed station, because its use of frequencies can be co-ordinated with the use made by other fixed stations of the sane frequencies. On the other hand, a transportable station which is set up to operate at unspecified points but is always stationary when it is in operation is nevertheless classified as mobile.

RRs 1.26, 1.28 and 1.32 define the land mobile, maritime mobile and aeronautical mobile services respectively according to the nature of the mobile stations involved. RRs 1.71, 1.75 and 1.81 give the terms “base station”, “coast station” and “aeronautical station” to the land stations of the land mobile, maritime mobile and aeronautical mobile services respectively. Corresponding terms for the mobile stations, defined in RRs 1.73, 1.77 and 1.83 are “land mobile station”, “ship station” and “aircraft station”.

RR 1.25 defines the mobile-satellite service as“a radiocommunication service; between mobile earth stations and one or more space stations or between space stations used by this service; or between mobile earth stations by means of one or more space-stations. This service may also include feeder links necessary for its operation”

RR 1.115 defines a feeder link as“a radio link from an earth station at a specified fixed point to a space station, or vice versa, conveying information for a space radiocommunication service other than the fixed-satellite service”.

However RR 1.21, which defines the fixed-satellite service, permits the inclusion of feeder links in the FSS. Thus, a country which sets up a mobile-satellite service has the option of assigning frequencies from one of the mobile-satellite allocations or one of the FSS allocations to the feeder links.

Some frequency bands have been allocated to the mobile-satellite service (MSS) and they may be used for service to any kind of mobile earth station. However, RRs 1.27, 1.29 and 1.35 define the land mobile-satellite service (LMSS), the maritime mobile-satellite service (MMSS) and the aeronautical mobile-satellite service (AeMSS) and other frequency bands have been allocated specifically for these more specialised purposes. Also RRs 1.78 and 1.84 provide terms for ship and aeronautical earth stations in the corresponding mobile service while RRs 1.76 and 1.82 provide terms for the corresponding land earth stations.

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4.2.2. Frequency allocations and frequency sharing.

It is of interest to compare the FSS and the various MSSs with regard to the ways in which the use of the spectrum by these services can be regulated.

(a) The FSS has need for a very large allocated bandwidth because the information flow which it has to transmit is very large. However, at the tine when its main frequency allocations had to be made, sharing constraints were devised which allowed both FSS and the terrestrial fixed service to operate in the same frequency band, each service having little effect on the other. As a result, wide frequency sharing allocations were agreed at WARC-63 and WARC-71, providing for the expected growth of the FSS over many years. (The development of the FSS for small-dish systems is, to some degree, limited by these sharing constraints and by the associated coordination; much of this problem can, however, be overcome by national and regional arrangements. )

(b) On the other hand, all currently foreseen MSS systems will use quite small earth station antennas. In general this demands high down-link PFD and high up-link receiver sensitivity, to a degree that makes sharing with terrestrial services difficult. For the same reason, sharing with other space services, such as the FSS, also presents difficulties. Therefore frequency allocations for the various mobile-satellite services, especially those intended for commercial systems, tend to be exclusive (that is, not shared) and narrow. Considerable use is made of special constraints and special coordination procedures to permit a maximum amount of sharing between local MSS systems and other services in geographically separated areas.

(c) Nevertheless, mobile satellite networks have to be coordinated with one another and with the stations of other services, space or terrestrial, which share the same frequency bands with equal status. The methods set out in Article 9 of the RR and used for the FSS are used for the MSSs also, but in most cases without applicable ITU Recommendations on interference levels. Where the allocation status of the mobile-satellite service allocation is inferior to that of the other sharing service, other procedures and constraints may apply in addition to Article 9.

Despite these frequency allocation problems, allocations have been made to the various MSSs in many bands ranging from 137 MHz to 265 GHz. At first sight this is a surprisingly large frequency range for a group of services which must operate under severe technical constraints. The bands above 50 GHz can, no doubt, be regarded as provision for future uses which are not yet clearly foreseeable; but use is made, in current or planned systems of bands ranging from 137 MHz to 44 GHz. Some consideration of why this wide frequency range is of interest follows.

4.2.3. Choice of radio frequency for MSS systems.

For all satellite systems the cost of RF power fed into the satellite antenna is high and it is economically desirable to select frequency bands for a specific system so that the maximum C/N ratio is delivered to the earth station receiver demodulator for unit satellite transmitter power in a given bandwidth. The noise level does not vary greatly throughout the frequency range in question and the designer’s objective must be to minimise transmission-loss between the antenna terminals.

For the FSS the choice is rather simple; the allocated bands start at 3.4 GHz, it is desirable to use bands close to this bottom limit unless other factors (such as terrestrial interference) are paramount, but a relatively small penalty is paid at higher frequencies up to say 15 GHz. Above which the penalty due to rain attenuation becomes significant.

It is much more complicated for the mobile-satellite services. The essence of the mobile-satellite frequency selection situation can be expressed as follows. Let it be assumed that the gain of the satellite antenna is fixed, to the extent that this is technically feasible, being determined by the required coverage area. Then

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(a) As the frequency is reduced, the size of the satellite antenna which is needed to provide constant gain increases, and it may become too big to launch. Thus, the gain of the satellite antenna may start to fall away below a certain frequency, and this fall-away will occur at a higher frequency as the size of the coverage area is reduced. This gain fall-away causes the transmission loss to fall away below a critical frequency

(b) For a given satellite antenna gain and a given earth station antenna size, the transmission loss between satellite and earth station is substantially constant regardless of operating frequency. However, as the frequency is raised, the antenna gain of the mobile station increases and its beamwidth is reduced, causing satellite tracking to become more costly.

(c) with antennas of constant gain at both the satellite and the earth station, the transmission loss increases by 20 dB for every 10-fold increase in the frequency. This can most conveniently be visualised by considering a satellite transmission being received at an earth station. As the frequency rises, the satellite PFD at the earth’s surface remains constant but the cross-section area of the earth station antenna shrinks, causing the amount of power which it captures to be reduced.

The satellite tracking capabilities of the mobile earth station are critical;

(a) a very simple, very cheap antenna which requires no tracking at all, might have a gain of about 8 dB and would probably be small enough to be mounted on most vehicles, regardless of frequency, between 137 MHz and 265 GHz.

(b) an antenna on a ship or aircraft with a beamwidth of about 10 degrees could be made to track a satellite with a relatively simple tracking system. It would have a maximum gain of about 25 dBi. However, at about 2 GHz a reflector antenna of this gain would have a diameter of 1 metre, and this might be taken as a maximum size for many applications; accepting this limit, the gain for lower frequencies would drop away at 20 dB for each 10-fold reduction in frequency.

(c) nevertheless, where high cost is tolerable in order to achieve high performance, typically in military systems, much better tracking is feasible, although the space limitations may be no less severe. Let it be assumed that the limits are 1degree minimum beamwidth and 1 metre maximum diameter. Such an antenna would provide a gain of about 45 dBi for frequencies above about 20 GHz, the gain dropping away at the sane rate as before for lower frequencies.

Bringing these factors together,

(1) For a minimum earth station antenna size, minimum cost system, such as might be used for paging or data systems, commercial road vehicles, small ships, commercial aircraft or survival craft, etc., frequencies well below 1 GHz are desirable, particularly for wide coverage systems. The transmission loss is comparatively high at best and rises rapidly with rising frequency.

(2) Where a larger earth terminal antenna of medium cost is acceptable, typical of larger INMARSAT systems, the transmission loss is less than for the previous case and the optimum frequency band is higher, say 800 MHz to 2 GHz (and even higher for satellites with multiple spot beam antennas). Note that multiple spot beam antenna arrays can be used to combine global coverage with higher satellite antenna gain.

(3) For a high performance, high cost earth terminal, the transmission loss can be less than for the other systems and the frequency range of interest spreads from below 1 GHz to at least 30 or 40 GHz, particularly for satellites with spot beams. Consideration would have to be given to the effect of rain and cloud on propagation to surface vehicles and ships at the upper end of this frequency range. Above 50 GHz, use for surface vehicles seems improbable because of gaseous absorption.

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4.2.4. Frequency allocations for the mobile satellite service

The series of WARCs and WRCs since 1988 have progressively made more spectrum available for mobile satellite systems. Recent proposals have concentrated on low-cost “little LEO” systems for paging or data services at frequencies below 1GHz where only limited spectrum bandwidth is available, but particularly on bands between 1 and 3 GHz where a variety of personal communciation satellite services and other mobile applications have been proposed. These include spectrum for third generation cellular systems, called IMT2000 by the ITU, and UMTS by Europe. These “big LEOs” use LEO or MEO orbits and have had a substantial impact on the consideration of allocations in the spectrum range. It is likely that most of these systems will not be implemented due to market considerations and to the difficulties of frequency sharing , but provision has to be made to allow for all significant proposals.

The bands now allocated are as follows, however most bands are shared with other space and terrestrial services and it is likely that not all frequencies will be used in all countries. The situation is still very fluid and developments should be monitored carefully over the next few years.

137 - 138 MHz down link partly secondary allocations148 - 150.05 up link235 - 322 footnote provision subject to not causing interference312 - 315 up link335.4 - 399.9 footnote provision subject to not causing interference387 - 390 down link399.9 - 400.05 up link400.15 - 401 down link406 - 406.1 up link455 - 456 ) Region 2 only459 - 460 ) up link

1525 - 1559 MHz down link ) mainly maritime and aeronautical mobile with some land1610 - 1660.5 up link ) mobile as secondary in some parts

1980 - 2010 up link2170 - 2200 down link2483.5 - 2520 down link2670 - 2690 up link7250 - 7375 down-link ) footnote provision subject to not causing interference7900 - 8025 up-link )

19.7 - 21.2 GHz down-link29.5 - 31 up link

There are also MSS allocations, at 39.5 - 40.5 GHz, 43.5 - 47 GHz and at other millimetre-wave frequencies. All of these allocations are shared with several other services, all with primary status. The use of the millimetre-wave spectrum is still in a very early stage, and it may be assumed that this part of the frequency allocation table will be changed in many respects before substantial use is made of these bands.

4.2.5. Emergency Position Indicating Radio Beacons.

There is an allocation to the mobile-satellite service, 406 - 406.1 MHz (up-links) which is earmarked for EPIRBs, which are used in search for and rescue of survivors from wrecked ships and aircraft as part of the. Global Maritime Distress and Safety System (GMDSS). Other frequency bands, more suitable for communicating with searching aircraft, have also been allocated for EPIRBs.

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4.3. The Broadcasting Satellite Service.

4.3.1. Definitions

The essential part of RR 1.38, which defines the (terrestrial) broadcasting service, limits the service to “transmissions intended for direct reception by the general public”. RR 1.39, which defines the broadcasting-satellite service (BSS) is broader, to take account of community antenna receiving systems (blocks of flats, hotels, arguably cable networks), as follows:

“a radiocommunication service in which signals transmitted by space stations are intended for the direct reception of the general public. In the BSS the term “direct reception” shall encompass both individual reception and community reception”.

RRs 1.129 and 1.130 define these latter terms as follows;

Individual Reception. “The reception of emissions from a space station in the BSS by simple domestic installations and in particular those possessing small antennas.”

Community Reception. “The reception of emissions from a space station in the BSS by receiving equipment, which in some cases may be complex, and have antennas larger than those used for individual reception, and intended for use by a group of the general public at one location or through a distribution system covering a limited area.”

The term “direct broadcasting by satellite” (DBS) is widely used in place of BSS among broadcasters.The BSS has been allocated frequency bands for transmissions from the satellite to the earth but not for the link from the programme source, on the Earth, to the satellite. This upward link is called a “feeder link”, which RR 1.115 defines as:

“a radio link from an earth station at a given location to a space station, or vice versa, conveying information for a space radiocommunication service other than for the FSS. …”

Feeder links for BSS satellites are permitted to operate in up-link frequency allocations of the FSS. Frequency bands were allocated to the FSS by WARC-79 specifically for this purpose. It should be noted that satellites operating in FSS allocations, intentionally or not, already provide extensive television facilities which cannot readily be distinguished from BSS. Much of the market domestic direct broadcast by satellite is provided in this way.

4.3.2. Frequency allocations for the BSS.

4.3.2.1 TV down-links

It has been agreed that the international acceptance of the right for the BSS stations of one country, to the use of a radio frequency assignment without unacceptable interference shall depend, not on priority of registration in the MIFR but on adherence to an agreed frequency assignment plan. This fact has a major effect on sharing of allocations with other services.

The following allocations are made for BSS in the international frequency allocation table. All of these allocations were made at WARC-71, although a few minor changes were made at WARC-79, and major sharing complications arise with most of them.

620 - 790 MHz. This is a footnote allocation worldwide. The USSR made some use of this band for BSS but substantial future use seems unlikely.

2520 - 2690 MHz. BSS shares this band with fixed and mobile terrestrial services with equal primary allocations and is limited to “national and regional” BSS networks for

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community reception

The main bands are at 12 GHz, where the following primary BSS allocations have been made forindividual reception (although community reception is not excluded);

Region 1; 11.7 - 12.5 GHzRegion 2; 12.2 - 12.7 GHzRegion 3; 11.7 - 12.2 GHz

These bands are also allocated to terrestrial fixed and broadcasting services with primary status and to the mobile service but with regional variations as to allocation status, and in Region 2 the FSS is also allocated this band.

At 12 GHz other allocations have been made for the BSS, intended for community reception,thus;

Region 2; 11.7 - 12.2 GHzRegion 3; 12.5 - 12.75 GHz

Both of these allocations are shared with the FSS and the terrestrial fixed service, both primary.

22.5 - 23.0 GHz in Regions 2 and 3 only, sharing with the fixed, mobile and inter-satellite services. Use by the BSS is subject to coordination.. With the 12 GHz bands listed above committed for 625/525 line TV for the foreseeable future, interest has been shown

in using the 22 GHz band for high definition TV (HDTV) and in getting the same band or a similar band allocated in Region 1 for this purpose. It may be doubted whether it would be feasible to use this band for BSS without a radical improvement in the allocation status of the service relative to any sharing services. The bandwidth now allocated seems likely to be too narrow to be used on a substantial scale for HDTV, in particular having regard to current a priori planning policies in the ITU.

40.5 - 42.5 GHz and 84 - 86 GHz. There are sharing service allocations in these bands but the status of the BSS allocations is such that problems should not arise for BSS from this sharing. However, radio propagation between space and Earth will be subject to severe losses, in particular in the troposphere, and use seems unlikely in the foreseeable future.

4.3.2.2. Sound broadcast down links

At WRC-95 allocations were made for satellite sound broadcasting. The band from 1452 to 1492 MHz is allocated and is limited to digital audio broadcasting, and is subject to the convening of a competent conference for the planning of the services and the development of procedures for the coordinated use of complementary terrestrial broadcasting in the band. This band was allocated after discussion concerning an alternative band at 2.5 GHz. As indicated earlier, a band in this range, 2520 to 2670 MHz, was allocated to the broadcasting satellite service, shared with fixed and mobile terrestrial services.

4.3.3. FSS allocations for feeder links for BSS systems.

As with the BSS allocations, the decision to use frequency assignment plans in the BSS has a major effect on the use of FSS allocations for feeder links and on sharing of bands with other services.In principle BSS feeder links can be assigned frequencies in any FSS up-link band, but if any considerable use was made of this option the amount of bandwidth remaining available for FSS networks would be seriously reduced. In particular, the preparation of a frequency assignment plan for feeder links would effectively deprive FSS networks of a large proportion of the allocated bandwidth intended for them, even if most of the feeder link assignments in the plan were never taken into use.

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WARC-79 acted to reduce this risk by making various new allocations to the FSS specifically for feeder links to broadcasting satellites transmitting in the main BSS allocations, as follows;

a) 10.7 - 11.7 GHz. (Region 1 only) (shared with FSS down-links etc.)b) 14.5 - 14.8 GHz. (excluding Europe, see RR 5.506)c) 17.3 - 18.1 GHz. (17.7 - 18.1 GHz shared with FSS down-links etc.)d) 27.0 - 27.5 GHz. This band is allocated in Regions 2 & 3 to the FSS for feeder links for BSS e) systems operating in the 22.5 - 23.0 GHz band, although there is no explicit indication of this intention in the ITU Table of Frequency Allocations.f) 47.2 - 49.2 GHz is earmarked, in a non-binding way, by RR |S5.552 for feeder links to BSS

systems operating in the band 40.5 - 42.5 GHz.g) Around 80 GHz there is no frequency band which is explicitly earmarked for feeder links for satellites broadcasting in the 84 - 86 GHz band but there is 1.5 GHz more FSS bandwidth allocated for up-links than down-links in this part of the spectrum and it may be foreseen that this surplus would be available for feeder links.

The prospect of sharing the bands 17.7 - 18.1 GHz (and perhaps also 10.7 - 11.7 GHz) between feeder links and FSS down-links introduces new situations in frequency sharing. Not all of these situations have been completely studied. The main new interference situations are:

from feeder link earth station transmitter to nearby FSS earth station receiver.from FSS satellite transmitter to a feeder link receiver on a BSS satellite nearby in orbit.from FSS satellite transmitter to a feeder link receiver on a BSS satellite separated from it angularly in orbit by about 160 degrees, the “quasi-antipodal case”.

The new situations arising for the terrestrial services using the same frequency bands are also causing some concern.

4.4. Other Space Services

The ITU recognises 11 other space radio services. It also recognises radio astronomy (RA), which is akin to several space radio services but is not classified by the ITU as one of them because its definition (RR 55) does not include the use of satellites. One of these 11 other space services, the inter-satellite service (ISS), has not developed to any considerable extent yet but it will no doubt one day be a major commercial service like the FSS and the MMSS. The amateur-satellite service is already vigorously active in the rather different circumstances of the amateur world. The remaining 9 services, plus RA, have a number of features in common:

these services are typically operated by governments or large organisations the satellites and other spacecraft involved are not usually geostationary the earth stations, in most cases, are few and can be located where interference from terrestrial stations will not be a major problem. the frequency allocations which have been made to these services are many but narrow, often national and often secondary in status.

The frequency allocations to several of these services have poor status. However, the use of “moving” satellites makes interference intermittent and this usually reduces its impact. The fact that earth stations can be located at will and that the services are operated by governments (which also have control of the administration of the use of radio frequencies) further ensures that the disadvantages of seemingly unsatisfactory frequency allocations does not prevent satisfactory operation of these services.

In general the ITU-R require the use of the same processes for frequency assignments to stations of these services as for other space radio services, typically notification of frequency assignments to the BR, coordination and registration for the emissions of these services as for any other radio service.The circumstances of these services are highly specialised, and it would be impractical and perhaps

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uninteresting to review them in detail. In the sections which follow the allocations to these services and major sharing problems, particularly those which have impact on the major space services, are reviewed briefly.

4.4.1.The Inter Satellite Service

The ITU definitions of several space services include satellite to satellite links as well as satellite-earth links, in particular that of the SRS; consequently the frequency bands allocated to these services can be used for satellite to satellite links unless there are direction designators with the allocation which do not permit this. Other service definitions, such as those of the FSS and the BSS, do not include inter-satellite links. However, there is an inter-satellite service (ISS) which can be used for inter-satellite links (ISLs) of any service.

ISLs do not pass through the earth’s atmosphere and so they are not affected by absorption and depolarisation due, for example, to molecular resonances in atmospheric gases and rain. Absorption is particularly severe, for example, in the neighbourhood of 60, 118 and 180 GHz. For these reasons the main ISS allocations have been put into those parts of the spectrum which are unsuitable for many terrestrial uses. These main allocations are;

54.25 - 58.2 GHz 126 - 134 GHz 59 - 64 GHz 170 - 182 GHz 116 - 126 GHz 185 - 190 GHz

All of these allocations are primary, sharing with other primary services, all terrestrial. For various reasons, including the gaseous absorption in the atmosphere and the low gain of typical inter-satellite antennas in the direction of the Earth, it is unlikely that this sharing will raise problems.In addition to these main allocations, 22.55 - 23.55 GHz and 32 - 33 GHz were also allocated to the ISS. Both allocations are primary, sharing with other primary services, and some of these sharing arrangements raise problems. Particularly difficult would be the sharing with BSS at 22.5 - 23.0 GHz. These allocations were made at a time when INTELSAT was giving serious consideration to the use of ISLs and it was foreseen that reliable active devices operating at 55 GHz and above would take a long time to develop and prove for space. INTELSAT decided not to proceed with the idea at the time.Little or no use is made of any of these allocations for ISLs at present. A beginning has been made in developing procedures for coordinating ISLs. The use of lasers for ISLs is under study.

4.4.2. The Amateur Satellite Service.

The amateur-satellite service (AmSS) has been allocated several groups of frequency-bands. Six HF bands allocated with primary status to the terrestrial amateur service, at 7, 14, 18, 21, 25 and 29 MHz, are shared with the amateur-satellite service. Similarly there is a primary amateur-satellite allocation at 144-146 MHz, shared with the terrestrial amateur service. Five narrowband allocations to the amateur-satellite service, at 435, 1260, 2400, 3400 and 5660 MHz are made by footnote on a non-interference basis, the primary allocations being radiolocation. (The 3400 MHz allocation is for Regions 2 and 3 only). A band at 5840 MHz, limited to up-links, is secondary for the AmSS, shared with the FSS (up-links also) which is primary, and other services. A band at 10.5 GHz is allocated secondarily to AmSS, radiolocation being primary. The bands 24.0 - 24.05 GHz, 47.0 - 47.2 GHz, 75.5 - 76 GHz, 142 -144 GHz and 248 - 250 GHz are allocated to AmSS on a primary basis, sharing with the terrestrial amateur service, which is also primary. The bands 76 - 81, 144 - 149, and 241 - 248 GHz are allocated to AmSS on a secondary basis, radiolocation being primary. No other conditions are applied by the ITU to the use of these AmSS allocations.

4.4.3. The radiodetermination satellite service

The ITU definitions of the services in which radio is used for navigation or for detecting the location of objects are at RRs 1.9 to 1.40 to 1.49 but they are not very explicit definitions. The following

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unofficial explanation may be found more helpful. RR 1.9 defines radiodetermination as “the determination of the position, velocity and/or other characteristics of an object, or the obtaining of information relating to these parameters, by means of the propagation properties of radio waves”.

The ITU, by long tradition, gives high importance to protecting from interference any service on which the safety of life depends; accordingly radiodetermination systems are divided between two services:

those which involve safety of life factors, called the radionavigation (RN) service. those in which no safety of life factors directly arise, called the radiolocation (RL)

service.

For example, a coast station which provides direction-finding facilities to ships, operating perhaps at 500 kHz, a coastal radar station which is used to provide warning to ships in crowded sea lanes if they are in danger of collision and the glide-plane beacon at an airfield are all kinds of radionavigation system. A military radar used to detect the presence of hostile aircraft is a radiolocation system.Maritime RN and Aeronautical RN services are defined in RR 1.44 and 1.46 respectively but it has not been found necessary to subdivide the radiolocation service.

RR 1.41 defines the radiodetermination-satellite service (RDSS) as “a radiocommunication service for the purpose of radiodetermination involving the use of one or more space stations”. RR 1.43, 1.45 and 1.46 provide corresponding definitions for RNSS, MRNSS and AeRNSS. No radiolocation-satellite service has been defined so far. (It may be noted that radars carried by satellites and used for the study of earth resources are part of the earth exploration-satellite service and are called “active sensors”.)

Although four services in the group (RDSS, RNSS, MRNSS and AeRNSS) have been defined, the RNSS is the only one to which any significant frequency allocations have been made so far.

The same system factors which affect the choice of frequency band for mobile-satellite systems arise for many existing and potential RNSS systems also. There are, in fact, five significant RNSS allocations below 40 GHz, together with a number of allocations above 40 GHz which can be disregarded for the time being, as follows:-

149.9 - 150.05 MHz and 399.9 - 400.05 MHz. These are world-wide allocations which were used for the Transit navigation system.

1215 - 1260 MHz (down-links). This allocation is primary and world-wide but it is shared with terrestrial RL (also primary), and with other terrestrial services in many countries. These allocations are used for the US Global Positioning System (GPS) or Navstar.

1559 - 1610 MHz (down-links). This allocation is primary and world-wide and shares with terrestrial AeRN, also primary. These allocations are also used for GPS and for GLONASS

14.3 - 14.4 GHz (down-links). This allocation is secondary and shares with various other services, some with primary status, including FSS up-links. (To have a safety of life service with secondary status is anomalous. It may be that this allocation will not be used.)

There are also various millimetre-wave allocations to RNSS.

4.4.4. The space research, earth exploration satellite and meteorological satellite services

The space research service (SRS) is defined in RR 1.55 as “a radiocommunication service in which spacecraft or other objects in space are used for scientific or technological research purposes”. It will be noted that this definition is very broad.

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The earth exploration-satellite service (EESS) is defined in RR 1.51 as “a radiocommunication service between earth stations and one or more space stations ... in which:

information relating to the characteristics of the earth and its natural phenomena is obtained from active ... or passive sensors on earth satellites,

similar information is collected from airborne or earth-based platforms, such information may be distributed to earth stations within the system concerned, platform interrogation may be included.”

An active sensor is defined in RR 1.182 as “a measuring instrument in the EESS or SRS in which information is obtained by transmission and reception of radio waves”; it is in fact a special purpose radar which is used to probe the earth from space. A passive sensor in the EESS and the SRS obtains information “by reception of radio waves of natural origin” according to RR 1.183; it is typically a sensitive radiometer which is directed at the Earth from space.

The meteorological-satellite service (MetSS) is defined in RR 1.52 as “an EESS for meteorological purposes.”

These services all need frequency allocations for three kinds of use: for active sensors for passive sensors for the transmission of observed data, control signals etc., typically to or from earth stations, but

links between satellites are not excluded.

The same frequency bands could be used by all three services for active sensors, and similarly for passive sensors and this arrangement is used with very few exceptions.Signals from active sensors operating at different radio frequencies penetrate to different depths into the atmosphere, the sea and the solid surface of the Earth and are reflected to different degrees. Thus there is a need for a variety of radio frequencies to be available for them. There are 10 allocations for active sensors operating in these three services, centred on the following frequencies:

1250 MHz 8600 MHz 17.25 GHz 78.5 GHz 3200 MHz 9650 MHz 24.15 GHz 5300 MHz 13.7 GHz 35.55 GHz

All of these bands are shared with terrestrial radiolocation, RL being primary and the active sensor allocations being secondary (except for 35.55 and 78.5 GHz, where they are primary). Some of these bands are also shared with other services. It seems that these sharing arrangements are tolerable to the SRS and EESS. There are 18 allocations for passive sensors below 40 GHz, centred on the following frequencies;

1385 MHz 4970 MHz 10.64 GHz 15.27 GHz 21.3 GHz 31.4 GHz 1412 MHz 6475 MHz 10.69 GHz 15.37 GHz 22.23 GHz 31.65 GHz 2647 MHz 7160 MHz 18.7 GHz 23.8 GHz 36.5 GHz. 2670 MHz

Some of these allocations are secondary, sharing as a rule with terrestrial services which do not use high power, but see next paragraph. Most of them, however, are primary and in some cases there is no sharing with an active service. There are other allocations above 40 GHz.

Exceptionally among the passive sensor bands, the one at 18.7 GHz (the actual band limits are 18.6 - 18.8 GHz) is shared with FSS down-links, among other services, and this sharing arrangement raises problems that have not yet been solved. The FSS allocation is primary world-wide; the passive sensor allocation is primary in Region 2 and secondary in Regions 1 and 3. It has been shown that energy scattered back upwards by the earth’s surface from FSS down-links would cause significant

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interference to passive sensors if the FSS were to take this band into full use and the FSS down-link power flux density at the earth’s surface were up to the limit determined by the need to avoid unacceptable interference to terrestrial radio relay systems. The Radio Regulations urge administrations to limit the pfd from FSS satellites in all Regions to permit the passive services to operate efficiently.

Among its allocations for communications links, the SRS has several which are set aside for communication with spacecraft in deep space, which the RR define as space further from the earth than the distance from the earth to the moon (there are proposals to change this to distances from the earth greater than 2 million km). These deep-space bands are centred on 2295 and 8425 MHz (primary), 2115 and 7190 MHz (subject to special coordination procedures) and 13.25 and 16.85 GHz (secondary). In addition to these bands, the SRS has a large number of allocations available for communication links between earth and space and between space stations. Most of these allocations are secondary. Many of them are allocated by footnotes to the frequency table and are quite local in their application; they have often been allocated for use at one particular rocket launching centre. However, the SRS is a nimble service, and can operate effectively under such conditions.

The most important of the EESS allocations for data readout from spacecraft is at 8025 - 8400 MHz; this down-link allocation is primary in Region 2 but secondary in Regions 1 and 3, sharing with FSS up-links with primary allocations in all three Regions. The fact that FSS and EESS use the band in opposite directions eliminates much of the apparent sharing problem. There are other allocations for EESS communication links, all but one of them secondary, leaving the EESS with substantial problems.

The MetSS has the following allocations for communications purposes;

400.15 - 401 MHz, down-links, primary.401 - 403 MHz, up-links, secondary.460 - 470 MHz, down-links, secondary, sharing with terrestrial services (fixed and mobile)

with primary allocations.1670 - 1710 MHz, down-links, primary.7450 - 7550 MHz, down-links, primary, sharing with FSS down-links.8175 - 8215 MHz, up-links, primary, sharing with FSS up-links18.1 - 18.3 GHz, down-links, primary, limited to geostationary satellites and shared, in

particular with FSS down-links.

4.4.5. The space operation service.

Signals for telemetering conditions on board satellites, for the remote control of the payload on board the satellite, for the remote control of the orbital, attitude and thermal adjustment devices on the satellite and so on may be transmitted in the frequency bands allocated to the main mission of the satellite. For example in the FSS, these housekeeping services commonly operate in bands allocated to the FSS.

However, there is also a need for separate frequencies to be available to carry out such housekeeping functions, in common for all services, particularly at the launch phase, and this is one of the functions of the space operation (SO) service. SO is also used, for example, for control of launchers and for many scientific missions,

The SO service has 6 very narrow allocations between 400 and 550 MHz, all shared and most of them peculiar to specific countries with an interest in satellite or space probe launching. The bands 1427 - 1429 MHz (up-links), 1525 - 1530 MHz and 1530 - 1535 MHz (both down-links) are primary and world-wide but the last-mentioned will be shared with MMSS (also down-links) from 1.1.90. The bands 1750 - 1850 MHz, 2025 - 2110 MHz and 2110 - 2120 MHz (all up-links), 2200 - 2290 MHz (down-links) and 7125 - 7155 MHz (up-links) are all allocated to SO by footnotes, some with various geographical limitations, some with various sharing problems and some subject to special coordination

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procedures. The current trend is to transfer operations from the lower bands, which are becoming overloaded, to the 2 GHz bands.

4.4.6. The standard frequency and time signal satellite service.

The SFSS has allocations as follows.400.05 - 400.15 MHz, primary and exclusive.4200 - 4204 MHz (down-links) and 6425 - 6429 MHz (up-links) subject to special

coordination procedures.20.2 - 21.2 GHz (down-links) & 30.0 -31.3 GHz (up-links), secondary, sharing with FSS.25.25 - 27.0 GHz (up-links), sharing with primary terrestrial services.

These allocations are confused and problems of coordination can be foreseen. However, it may be some years before major projects emerge for this service, and there will no doubt be a chance to clear the problems up at some future WRC.

4.4.7. Radio Astronomy

Radio astronomy is defined in RR 1.13 as “astronomy based on the reception of radio waves of cosmic origin”. Strictly speaking it is not a space service at all, but it has much in common with space services and it is convenient to consider it briefly along with the space services. The service has a large number of allocations and they fall into two groups. Some relatively wide allocations form a series of windows through which astronomers can measure the variation with frequency of the continuum of radio emissions from cosmic sources. Other bands are very narrow, but their location in the spectrum has been chosen very precisely to coincide with the frequency of spectral lines in the cosmic emissions. For both kinds of application the extremely high sensitivity of RA observatories, especially to interference from satellites, and the adverse sharing conditions which arise in some bands make interference a prime problem.

In general the interference problems which are due to emissions from terrestrial stations have to be eliminated by the action of the national radio frequency authority, who must refrain from assigning frequencies to terrestrial stations in the vicinity of an observatory which observes them if they wish to protect the observatory.

5. CASE STUDY – The High Density Fixed Satellite Service

The continuing growth in the demand for high data rate services to the domestic user and small businesses has been responded to by the introduction of a variety of means of delivery. Radio services have advantages of flexibility and rapid deployment. However terrestrial schemes for high density fixed wireless access at SHF or EHF require extensive infrastructure which limits the rate at which systems may be deployed and may mean that such networks will never be available in more rural areas.

Thus there may be scope for the introduction of high density satellite services. An early attempt at this was the Teledesic network, but there continue to be opportunities for both GSO and non-GSO services.

This has been highlighted in ITU-R Resolution 143, adopted at the recent WRC in 2003. This is reproduced in the annex. WRC-03 also identified bands which may be suitable for HDFSS:

space to earth

17.3-17.7 GHz Region 118.3-19.3 GHz Region 219.7-20.2 GHz 39.5-40 GHz Region 140-40.5 GHz40.5-42 GHz Region 2

47.5-47.9 GHz Region 148.2-48.54 GHz Region 1

49.44-50.2 GHz Region 1earth to space

27.5-27.82 GHz Region 128.35-28.45 GHz Region 228.45-28.94 GHz

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28.94-29.1 GHz Region 2 and 329.25-29.46 GHz Region 229.46-30 GHz

48.2-50.2 GHz Region 2.

The Radio Regulations state that this identification for HDFSS does not preclude the use of these bands by other fixed-satellite service applications or by other services to which these bands are allocated on a co-primary basis and does not establish priority in these Regulations among users of the bands.

The Resolution in the considerings identifies the potential advantages of HDFSS.

The notings indicate some difficulties due to frequency sharing with other services, but it may be expected that these difficulties will be overcome following further studies of frequency sharing or by the selection of frequency assignments.

The recognizing notes the administrative difficulties of detailed coordination when many small earth stations are involved. It may be expected that suitable simplified procedures will be developed.

The resolves and invites encourage the use of some bands on a harmonized basis.

One aspect for consideration is the description of this application as being high density. The density of users and the frequency reuse distances across the surface of the earth can never compete with those achieved with terrestrial networks. Thus on a strict comparison it might not be appropriate to consider that a satellite network could deliver a high density of usage. However, within the satellite context these services, by using high gain antennas with small footprints, do achieve a high density as compared with other satellite applications.

HDFSS may offer the opportunity for the provision of broadband services in areas which are not likely to be offered services by other means.

ANNEX

RESOLUTION 143 (WRC-03)

Guidelines for the implementation of high-density applications in the

fixed-satellite service in frequency bands identified for these applications

The World Radiocommunication Conference (Geneva, 2003),

consideringa) that demand has been increasing steadily for global broadband communication services throughout the world, such as those provided by high-density applications in the fixed-satellite service (HDFSS);

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b) that HDFSS systems are characterized by flexible, rapid and ubiquitous deployment of large numbers of cost-optimized earth stations employing small antennas and having common technical characteristics;c) that HDFSS is an advanced broadband communication application concept that will provide access to a wide range of broadband telecommunication applications supported by fixed telecommunication networks (including the Internet), and thus will complement other telecommunication systems;d) that, as with other FSS systems, HDFSS offers great potential to establish telecommunication infrastructure rapidly;e) that HDFSS applications can be provided by satellites of any orbital type;f) that interference mitigation techniques have been and continue to be studied in ITU-R to facilitate sharing between HDFSS earth stations and terrestrial services;g) that to date, studies have not concluded on the practicability of implementation of interference mitigation techniques for all HDFSS earth stations,

notinga) that No. 5.516B identifies bands for HDFSS;b) that, in some of these bands, the FSS allocations are co-primary with fixed and mobile service allocations as well as other services;c) that this identification does not preclude the use of these bands by other services or by other FSS applications, and does not establish priority in these Regulations among users of the bands;d) that, in the band 18.6-18.8 GHz, the FSS allocation is co-primary with the Earth exploration-satellite service (EESS) (passive) with the restrictions of Nos. 5.522A and 5.522B;e) that radio astronomy observations are carried out in the 48.94-49.04 GHz band, and that such observations require protection at notified radio astronomy stations;f) that co-frequency sharing between transmitting HDFSS earth stations and terrestrial services is difficult in the same geographical area;g) that co-frequency sharing between receiving HDFSS earth stations and terrestrial stations in the same geographical area may be facilitated through the implementation of interference mitigation techniques, if practicable;h) that many FSS systems with other types of earth stations and characteristics have already been brought into use or are planned to be brought into use in some of the frequency bands identified for HDFSS in No. 5.516B;i) that HDFSS stations in these bands are expected to be deployed in large numbers over urban, suburban and rural areas of large geographical extent;j) that the 50.2-50.4 GHz band, adjacent to the band 48.2-50.2 GHz (Earth-to-space) identified for HDFSS in Region 2, is allocated to the EESS (passive),

recognizinga) that in cases where FSS earth stations use bands that are shared on a co-primary basis with terrestrial services, the Radio Regulations stipulate that earth stations of the FSS shall be individually notified to the Bureau when their coordination contours extend into the territory of another administration;b) that, as a consequence of their general characteristics, it is expected that the coordination of HDFSS earth stations with fixed service stations on an individual site-by-site basis between administrations will be a difficult and long process;c) that, to minimize the burden for administrations, simplified coordination procedures and provisions can be agreed by administrations for large numbers of similar HDFSS earth stations associated with a given satellite system;d) that harmonized worldwide bands for HDFSS would facilitate the implementation of HDFSS, thereby helping to maximize global access and economies of scale,

recognizing furtherthat HDFSS applications implemented on FSS networks and systems are subject to all provisions of the Radio Regulations applicable to the FSS, such as coordination and notification pursuant to Articles 9 and 11, including any requirements to coordinate with terrestrial services across international borders, and the provisions of Articles 21 and 22,

resolvesthat administrations which implement HDFSS should consider the following guidelines:

a) making some or all of the frequency bands identified in No. 5.516B available for HDFSS applications;b) in making frequency bands available under resolves a), take into account:

– that HDFSS deployment will be simplified in bands that are not shared with terrestrial services;– in bands shared with terrestrial services, the impact that the further deployment of terrestrial

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stations would have on the existing and future development of HDFSS, and the further deployment

of HDFSS earth stations would have on the existing and future development of terrestrial services;

c) take into account the relevant technical characteristics applicable to HDFSS, as identified by ITU-R Recommendations (e.g. Recommendations ITU-R S.524-7 and ITU-R S.1594);

d) take into account other existing and planned FSS systems, having different characteristics, in frequency bands where HDFSS is implemented in accordance with resolves a) above and the conditions specified in No. 5.516B,

invites administrations1 to give due consideration to the benefits of harmonized utilization of the spectrum for HDFSS on a global basis, taking into account the use and planned use of these bands by all other services to which these bands are allocated, as well as other types of FSS applications;2 to consider implementing simplified procedures and provisions that facilitate the deployment of HDFSS systems in some or all of the bands identified in No. 5.516B;3 when considering the deployment of HDFSS systems in the upper portion of the band 48.2-50.2 GHz, to take into account as appropriate the potential impact such deployment may have on the satellite passive services in the adjacent band 50.2-50.4 GHz, and to participate in ITU-R studies on the compatibility between these services, taking into account No. 5.340;4 to, given invites 3 above, and where practicable, consider starting the deployment of HDFSS earth stations in the lower part of the band 48.2-50.2 GHz.

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