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Approaches to Frequency Planning for RRC-04/05

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Title: Approaches to Frequency Planning for RRC-04/05


1
Approaches toFrequency Planning for RRC-04/05
  • Nigel Laflin
  • Rapporteur for Chapter 3 of the TG6/8 report

2
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 230 MHz and
    470 to 862 MHz

3
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

Source of Interference Services to be protected Services to be protected Services to be protected Services to be protected
Source of Interference Analogue TV Bands III, IV, V Digital TV Digital Sound Other Services
Analogue TV assignments ST61/GE89 provisions To be established To be established ST61/GE89 provisions
Digital TV allotments/ assignments To be established To be established To be established To be established
Digital Sound allotments/assignments To be established To be established To be established To be established
4
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

5
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

6
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

7
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

8
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

9
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

10
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

11
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?

12
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)
13
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
14
Allotment planning reference networks
  • 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

Separation distances between reference networks
15
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

16
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

17
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 been applied 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

18
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

19
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

20
Example of a lattice-independent planning process
compatibility analysis and synthesis
  1. Submission of the input requirements for the
    digital broadcasting services
  2. Identify the analogue broadcasting services and
    other services to be protected
  3. Perform compatibility analysis
  4. Assess the results from step 3
  5. Allow for administrative input concerning
    compatibility between requirements
  6. Perform synthesis to produce a plan
  7. Review the results and loop back to step 3 if the
    desired result is not achieved
  8. Agreement of the final plan

21
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

22
Multi Frequency Networks (MFNs)
Coverage of service area
Border 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

23
Single Frequency Network (SFN)
Coverage of service area
C1
C1
C1
C1
C1
C1
C1
C1
C1
C1
  • All transmitters of the network use the same
    frequency channel
  • The transmitters provide a common coverage area
    and cant be operated independently they must
    carry identical multiplex content

24
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

25
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

26
The End
  • Thank you for your attention
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