Approaches to Frequency Planning for RRC-04/05

Approaches toFrequency Planning for RRC-04/05 Nigel Laflin Rapporteur for Chapter 3 of the TG6/8 report

Protection of analogue television, digital broadcasting and other services • Analogue television • Need to address conditions for the protection of existing stations • Administrations should indicate which of their existing and planned stations should be protected • Administrations should ensure that their entries in ST61, GE89 and Master Register reflect the actual co-ordinated situation (see table A.3.4-1 of TG 6/8 report) • Digital broadcasting • Need to address conditions for digital terrestrial television broadcasting currently recorded in the Master Register with favourable findings • Other services • Need to consider conditions for other services sharing the frequency bands 174 to 230MHz and 470 to 862MHz

Coordination procedures (1) • The new Agreement should include provisions and/or procedures for: • Coordination of unresolved cases • Modifications to the Plan • The transition from analogue to the all digital broadcasting situation • Inter/intra-service protection of analogue television, digital broadcasting and other primary services – see table below

Coordination procedures (2) • Coordination distances • Identify which administrations might be affected when an administration proposes to modify a plan by changing the characteristics of an existing assignment or allotment, or add a new assignment or allotment Examples for assignment planning are: • Tables giving limiting distance as a function of effective radiated power, effective antenna height and the nature of the path under consideration (ST61 Agreement) • Tables of distances between station in question and any point on the boundary of any other administration (GE89 Agreement) And for allotment planning: • The coordination distances based on standardised transmission reference values and separation distances (RJ88 Agreement) • Test points • Test points may be used in planning to describe coverage of coordinated stations, allotment areas, assignment requirements, or the boundary of other services to be protected

Planning principles - general • Planning process based on an inventory of administrations’ requirements • Equitable access to the frequency resources but account taken of the technical and economic constraints • Use of the minimum number of channels to satisfy requirements • Each administration to decide on compatibility of digital plan with existing services in its own country and to indicate which existing and planned stations should be protected • Proposed digital allotments/assignments open to bilateral or multilateral negotiation between administrations concerned • Based on results of planning exercises incompatibilities should be resolved by bi/multilateral discussions prior to Second Session • Planning provisions for countries not present • No account to be taken of low power digital assignments in the planning process – these can be entered later

Planning Bases • Procedure for production of a plan • Compatibility analysis: to identify incompatibilities arising from input requirements - appropriate responses to these problems would be considered by the Planning Conference • Synthesis process: could be used to permit the rapid development of possible alternative frequency plans • Approaches to the Plan • Modification of the existing Plans – may not lead to an optimum plan for some countries but easy to implement (e.g. via the conversion of analogue assignments to digital assignments) • Completely new plan – greater spectrum utilisation efficiency but difficult to implement • Combination of both – likely scenario to facilitate the requirements of all countries in the planning area

Planning Scenario 1 All existing or planned analogue assignments would need to be protected from new digital assignments indefinitely • Administration can decide for itself when any of its new digital requirements can be brought into operation • The rights for ST61 and GE89 plans are retained • No constraints on the transition procedure • Minimal impact on the analogue services • Least potential for future digital development • May not offer the opportunity for full digital coverage

Planning Scenario 2 All existing or planned analogue assignments to be protected from new digital assignments, but the analogue assignments would be converted to digital and will form part of all-digital plan • Administration can decide when its digital requirements can be brought into operation analogue assignments converted to digital assignments • The rights for ST61 and GE89 plans are retained • No constraints on the transition procedure • Reduced opportunities for digital services • The spacing between digital stations (based on analogue network) may not be optimal • Potential interaction between digital requirements and assignments resulting from analogue conversions must be taken into account during the planning process

Planning Scenario 3 Analogue assignments can be converted to digital and incorporated in the new digital plan as required – no attempt to protect existing or planned analogue assignments • Administration can decide for itself when new digital requirements are brought into operation – provided that unwanted interference is not caused to analogue assignments of a neighbour • High potential for future digital development • If required, the rights for ST61 and GE89 plans are retained • Use of synthesis planning approach could facilitate a near ideal Plan • Transition process would require coordination with neighbouring countries • Necessary for the Agreement to contain procedures to allow for a transition to the all-digital Plan

Planning Scenario 4 New Plan – no need to retain or protect existing or planned analogue assignments • Greatest potential for future digital development • May have an application in situations where there are currently ‘unused’ channels • Administration will have little or no freedom to decide for itself when any given station could be brought into operation as considerable interaction with neighbouring administrations could be required • Necessary to develop complex transition procedures • No rights for ST61 and GE89 plans are retained

Planning Elements • First layer • What type of service is required: DVB-T, T-DAB? • What type of reception is required : fixed, portable? • Territorial coverage: complete, urban areas, regions? • Which existing and planned elements should be protected? • Second layer • Which DVB-T variant should be employed? • Which network characteristics should be chosen: antennas, distance between stations? • Third layer • Which network configuration should be employed: MFN/SFN? • Should entries in the Plan be allotments or assignments, or both?

Planning approaches: Assignments • In the past, terrestrial television planning in Europe has been by way of assignment conferences • The assignment plan provides a frequency for each station – at the completion of the planning process the locations and characteristics of the transmitters are known • Assignment planning, based on a lattice structure, is appropriate where transmitter sites can be assumed to have the same characteristics • The transmitters can be brought into service without further coordination • A lower limit for the radiated power is normally defined for stations within the planning process Examples of assignments used in lattice planning (ST61)

Planning approaches: Allotments • In general nothing is known of the actual location of the transmitter sites, or of the specific transmission characteristics to be used • The parameters required are a definition of the area to be covered, the channel and the interference potential of the allotment • In order to carry out planning it is necessary to define reference transmission conditions to calculate potential interference and facilitate compatibility calculations • The allotment plan provides frequencies to be used in particular areas without specifying the stations to which the frequencies are assigned Band III allotments areas from the Wiesbaden 1995 Plan

Reference networks are required to assess the outgoing interference potential with particular reference to: calculating the compatibility between allotment areas – including separation distance the generation of a set of calculation test points for the later conversion of allotments into assignments Allotment planning: reference networks Separation distances between reference networks

Assignment and/or allotment planning • Assignment planning is preferable • Where transmitter infrastructure is known • In the case of MFN or small SFN planning • Allotment planning is preferable • Where the transmitter infrastructure is not known • If channels are available for planning DVB-T services which are required to cover the whole of a larger area • If great potential for flexibility in terms of the implementation of transmitter networks within the Plan is desired • If portable reception is a prime requirement • General conclusion • Whilst allotment based planning requires more work after the conference, there is a major advantage in terms of flexibility in the subsequent development of transmitter networks and greater scope to accommodate future digital system developments

PLANNINGMETHOD Full or partial coverage Assignments Allotments Latticebased LatticeIndependent Latticebased LatticeIndependent Planning method • Lattice based: a systematic and geographically regular distribution of frequency resources over an area • Lattice independent: a pseudo-random but spectrum utilization efficient distribution of frequency resources over an area

Lattice-based methods • Lattice based methods assume: • Geometrically regular lattices, linear channel-distribution schemes • All transmitters are identical, their powers and antenna heights being the same • Antenna radiation patterns are omni-directional in the horizontal plane • Radio wave propagation losses are not a function of propagation direction and frequency • Lattice based methods have beenapplied with success for past planning/re-planning of AM or FM sound or televisions services where: • Empirical methods were difficult to implement • When some uniformity of standards exists for the services to be planned • There is freedom in assigning any frequency to any transmitter

Lattice-independent methods • Lattice-independent planning makes no assumption about the uniformity of the network and this can be a significant advantage where: • Coverage requirements depart from any approximation to a regular lattice – useful for a mixture of large and small areas requiring different programmes, and in areas where several countries meet and each has adopted a different coverage philosophy • A set of assignments needs to be added into an existing planned broadcasting situation, or there are analogue stations in the same part of the spectrum • Furthermore lattice-independent planning: • can permit a more-or-less continuous process of transition from analogue only • represents a close approach to optimum use of the spectrum when coverage areas are non-uniform

Choice of planning method or methods • Lattice based methods have successfully provided the basis for most of the past broadcasting plans and could be adopted for use for digital broadcasting planning in areas of relative uniformity of requirement characteristics • Lattice-independent planning seems highly likely to provide an optimum means to achieve both the desired coverage and the most efficient use of the available spectrum in areas of nonuniform requirements for digital television and/or sound broadcasting (very different sizes of coverage area and various reception conditions), and in areas where there are already networks of analogue stations

Submission of requirements Identify analogue andOS to be protected Perform compatibility analysis Administrative input on compatibility Results assessment Perform Plan synthesis Reviewresults Agreed Plan Example of a lattice-independent planning process ‘compatibility analysis’ and ‘synthesis’ • Submission of the input requirements for the digital broadcasting services • Identify the analogue broadcasting services and other services to be protected • Perform compatibility analysis • Assess the results from step 3 • Allow for administrative input concerning compatibility between requirements • Perform synthesis to produce a plan • Review the results and loop back to step 3 if the desired result is not achieved • Agreement of the final plan

Network structures and configurations • In principle there are two types of terrestrial digital broadcasting networks to be considered: • multi-frequency networks (MFN) which allow the same or different programmes to be carried by individual transmitters using different frequencies • single frequency networks (SFN) in which distributed emission is implemented whereby coverage is provided by multiple transmitters operating on the same frequency and carrying the same programmes • The network configurations for digital terrestrial broadcasting services can be implemented as MFN, as SFN or as mixed networks consisting of MFNs and SFNs • The type of network implemented depends on the availability of frequencies, the type of coverage required, the number of multiplexes to be provided and may depend on national constraints or strategies

Border of coverage area for an individual transmitter C1 C3 C3 C11 C9 C3 C5 C9 C5 C7 C1 C3 C1 Multi Frequency Networks (MFNs) Coverage of service area • Each transmitter uses a different frequency channel (Cx), acting independently and having its own coverage area • Re-use of channels is possible given sufficient geographical separation Border of service area

Border of coverage area Border of service area Single Frequency Network (SFN) Coverage of service area • All transmitters of the network use the same frequency channel • The transmitters provide a common coverage area and can’t be operated independently – they must carry identical multiplex content C1 C1 C1 C1 C1 C1 C1 C1 C1 C1

Considerations concerning MFN and SFN configurations • MFN • A large part of the existing analogue network infrastructure may be re-used particularly for fixed reception – this has cost-saving implications for the broadcaster and can also provide benefits for the viewer • SFN • The same frequency must be available over the whole coverage area • Existing analogue network infrastructures can be re-used although additional transmitters may be required to avoid self-interference • SFN planning allows for a more homogeneous field strength distribution for portable and mobile reception • Mixed MFN-SFN • Within an MFN of main stations, lower power stations may complete the coverage using the same frequency as the associated main station • An MFN structure for transmitting a national multiplex and an SFN structure for transmitting a regional multiplex • This type of mixed network scenario could arise from different approaches in adjacent countries

Other information available in Chapter 3 • A method for establishing the coverage area of coordinated (existing or planned) analogue stations • Details of the frequency bands used for television broadcasting within the planning area • Information concerning relevant digital terrestrial systems for television (ATSC, DVB-T and ISDB-T) and sound (T-DAB and ISDB-TSB) • An overview of digital broadcast systems intended for or already in use in the Bands III, IV and V (Annex A.3.3) which indicates that: • For Bands IV/V all countries with an entry intend to use DVT-T • For Band III the vast majority of European countries intend to use TDAB and DVB-T whilst for other parts of the planning area the current trend is towards DVB-T only

The End • Thank you for your attention

Approaches to Frequency Planning for RRC-04/05