METHODS FOR PREDICTING INTERFERENCE FROM RESPONSE STATION TRANSMITTERS
AND TO RESPONSE STATION HUBS AND FOR SUPPLYING DATA ON RESPONSE STATION
SYSTEMS. MM DOCKET 97-217

1.  This document sets out the methodology to be used in carrying out
    certain requirements with respect to response stations used as part
    of two-way cellularized MDS and ITFS systems. It details the methods
    for conducting interference studies from and to two-way systems, and
    it defines a file format to be used in submitting data in response
    station hub applications. It also describes the propagation analysis
    techniques to be used in these studies.

# Four Major Steps for Response Station Interference Analysis

2.  In carrying out the studies of interference from response station
    transmitters, the aggregate power of the interfering signals to be
    expected from the response station transmitters shall be determined
    using a process comprising four major steps, as described below.
    First, a grid of points shall be defined that is statistically
    representative of the distribution of transmitters to be expected
    within the response service area, and the elevations to be
    associated with each of them shall be determined. Second, any
    regions and any classes of response stations to be used shall be
    defined. Third, the appropriate transmitter configuration to be used
    in each interference study shall be determined. Fourth, the
    equivalent power of each of the representative transmitters shall be
    determined and used in the various required interference studies.
    The parameters used in the studies shall be provided in a prescribed
    electronic form as described later in this document.

## Defining Grid of Points for Analysis

3.  Since it is impossible to know *a priori* where response stations
    will be located, a grid of points is used to represent
    statistically, in a relatively small number of locations, the
    potentially much larger number of response stations that are likely
    to be installed in the areas surrounding each of the points. Once
    defined, the same grid of points shall be used by all parties
    conducting interference analyses involving the subject response
    station system.

4.  Defining the representative grid of points to use in all the
    interference studies required in Rule Sections 21.909 and 74.939
    begins by geographically defining the response service area (RSA) of
    the response station hub (RSH). This may be done using either a list
    of coordinates or a radius from the response station hub location or
    from the RSA reference point defined below when the hub is located
    outside the RSA. When coordinates are used, straight lines shall
    interconnect one location with the next in the order given in the
    list, and the last location described shall be connected to the
    first location by a straight line. When a radius from the response
    station hub location or the RSA reference point is used, the value
    shall be expressed in kilometers, with any fractional part expressed
    as a decimal value to two places. The boundaries described are
    administrative and serve to circumscribe the area in which response
    station transmitters may be located. When the response station hub
    is located outside the RSA, the reference point shall be that point,
    measured in degrees, minutes, and seconds to the nearest one-tenth,
    that is simultaneously midway between the eastern- and western-most
    extremes and midway between the northern- and southern-most extremes
    of the RSA. The same method for determining the reference point
    shall be used regardless of whether the RSA is defined as a radius
    or as a group of points. It should be noted that, when the response
    station hub is located outside the RSA and depending upon the shape
    of the RSA, the reference point also might fall outside the RSA
    using this method. The same consideration applies to Basic Trading
    Area and Partitioned Service Area reference points as defined later.

5.  The characteristics of any sectors in the RSH receiving antenna also
    must be described in two ways: geographically, so as to limit the
    locations from which response stations will transmit to each sector,
    and electrically, by providing data on the electrical field response
    of the antenna pattern in each sector. Sectors may overlap one
    another geographically. The geographic boundaries of a sector shall
    be defined using either a list of coordinates or a list of bearings.
    Electrical field response data shall be relative to the direction of
    maximum response of the sector antenna and shall be provided every
    one (1) degree completely around the antenna. Both azimuth and
    elevation field patterns shall be supplied for each polarization to
    be used with a given antenna type. The geographic orientation of
    each sector to the nearest one-tenth degree and the polarization in
    each sector also shall be specified. When response stations share
    channels or sub-channels by transmitting simultaneously on them, the
    maximum number of response stations that will be permitted to
    transmit simultaneously within each sector must be specified.

6.  The RSA may be subdivided into regions to allow different
    characteristics to be used for response stations in different
    portions of the RSA. (For details on regions and their use, see the
    section below on Defining Regions and Classes for Analysis.) Any
    regions to be used when analyzing interference must also be
    described in a manner similar to that used to describe the RSA
    itself. Analysis of the regions involves use of one or more classes
    of response station characteristics. For each such class, a
    combination must be specified of the maximum antenna height, the
    maximum equivalent isotropic radiated power (EIRP), and the worst
    case antenna pattern that will be used in practice in installations
    of response stations associated with that class within the
    respective regions. (For details on classes and their use, see the
    section below on Defining Regions and Classes for Analysis.) When
    response stations share channels or sub-channels by transmitting
    simultaneously on them, the maximum number of response stations
    associated with each class that will be permitted to transmit
    simultaneously within each region and each sector must be specified.

7.  To define the grid of points, a line is first established
    surrounding the RSA, 0.8 km outside the RSA boundary line. This is
    termed the "analysis line" and will be used in determining that an
    adequate number of grid points representing transmitters is being
    used in the interference analyses. A starting point is defined at
    the northernmost point on the analysis line having the same
    longitude as the reference point, no matter whether that reference
    point is within or outside the RSA. A series of analysis points is
    then spaced along the analysis line with the starting point being
    one of those points. The analysis points must occur with a spacing
    no greater than every 0.8 km along the analysis line or every
    5 degrees (as seen from the response station hub or RSA reference
    point), whichever yields the largest number of analysis points. When
    an RSA has a non-circular shape, the choice of distance along the
    analysis line or angle from the response station hub or RSA
    reference point must be made for each portion of the line so as to
    maximize the number of analysis points in that portion. The analysis
    points are to be described by their geographic coordinates. (The
    results of this method are that, for a circular RSA, a minimum of 72
    analysis points will be used, and that, for portions of the analysis
    line of any RSA more than 9.22 km from the response station hub or
    RSA reference point, the distance method will be used.)

8.  Next, the grid of points is defined within the RSA to statistically
    represent the response stations. The grid uses uniform, square
    spacing of the points, as measured in integer seconds of latitude
    and longitude, with the first square surrounding the RSH or RSA
    reference point and with its points equidistant from it. The lines
    connecting the points on one side of any grid square point true
    north, east, south, or west. The grid is defined so as to include
    all points within or on the boundary of the RSA, with the exception
    described in paragraph 9 below. Note that when the RSA reference
    point is outside the RSA, it is still the case that only points
    actually within the RSA are to be included. The result is that the
    grid can be defined by only two values --- the coordinates of the
    hub or RSA reference point and the separation between adjacent grid
    points in seconds --- combined with the description of the RSA
    boundary.

9.  Any points falling at locations within the RSA at which it would be
    physically impossible to install a response station (such as in the
    middle of a lake, but not the middle of a forest) are removed from
    the analysis. The points of the grid so inactivated are to be
    described by their geographic coordinates.

10. The grid of points is then divided into two groups. The division is
    to be done using a checkerboard pattern so that alternating points
    along the east-west and north-south axes belong to opposite groups
    and points along any diagonal line belong to the same group.

11. The combination of the grid of points within the RSA and the points
    on the analysis line is next used to determine that the number of
    grid points is truly representative of a uniform distribution of
    response station transmitters within the RSA. This is done by
    conducting a power flux density analysis from each grid point within
    the RSA to each point on the analysis line. For this analysis, a
    single response station should be assumed to be located at each grid
    point, that response station having the combined worst case antenna
    pattern without regard to polarization of all response station
    classes assigned to that grid point and the maximum EIRP of any
    response station class assigned to that grid point. (For details on
    the method for determining the combined worst case antenna pattern,
    see the section below on Defining Regions and Classes for Analysis.)
    The response station antennas all should be oriented toward the
    response station hub.

12. The analysis of grid point adequacy should be done using free space
    path loss over flat earth only and should not include the effects of
    terrain in the calculation of received signal levels. At each point
    on the analysis line, the power flux density from all grid points in
    each group of the checkerboard pattern should be aggregated. This is
    done by converting power received from each assumed transmitter from
    dBW/m^2^ to W/m^2^, summing the power in W/m^2^ from all
    transmitters in each group, and then converting the sum back to
    dBW/m^2^.

13. After the aggregated power flux density from each of the two groups
    has been calculated, the received power flux densities from the two
    groups are compared at each of the points on the analysis line. The
    power flux densities from the two groups must be within 3 dB of one
    another at each of the points on the analysis line. In addition,
    there must be no closer spacing of grid points that allows a
    difference of greater than 3 dB between the groups. If the power
    flux densities of both groups are within 3 dB at every analysis
    point, a sufficient number of grid points is included for use in
    further analyses. If they are not within 3 dB at every analysis
    point, a larger number of grid points (i.e., closer spacing of grid
    points) must be used so that the 3 dB criterion is met. If
    calculation of the spacing of grid points proceeds from larger to
    smaller spacings, the minimum spacing that should need to be
    investigated to check for smaller spacings not meeting the 3 dB
    criterion is 50 percent of the spacing at which the 3 dB criterion
    is first met.

14. In cases in which sectorized response station hubs are used, a
    further test is required to assure that an adequate number of grid
    points is used. In addition to meeting the requirements of the
    preceding paragraph, each sector must contain a minimum number of
    grid points. When the hub is within the RSA, the number of grid
    points within each sector shall be equal to or greater than the
    distance from the hub to the furthest point in the sector, expressed
    in kilometers, divided by three. When the hub is not within the RSA,
    the number of grid points within each sector shall be equal to or
    greater than the difference between the distances from the hub to
    the nearest point and to the furthest point in the sector, expressed
    in kilometers, divided by three. In both cases, there shall be a
    minimum of five active grid points per sector, and rounding shall
    always be to the next higher integer. Should an insufficient number
    of grid points fall within any sector after meeting the 3 dB
    criterion, the point spacing for the entire RSA must be decreased
    until this additional requirement is satisfied.

15. Once the geographic locations of the grid points are determined, the
    elevations to be attributed to each must be decided. This is done by
    creating a geographic square uniformly spaced around each grid point
    having a width and a height equal to the spacing between grid points
    and oriented in the same directions as the lines between grid points
    used to lay out the grid structure. Each such square is then
    examined with respect to all of the data points of the U.S.
    Geological Survey (USGS) 3-second database falling within or on the
    edge of the square to find the elevation of the highest such data
    point, expressed in meters. That elevation is ascribed to the
    associated grid point and shall be used for the elevation of that
    grid point in all further and future analyses of the response
    station system.

16. The geographic coordinate system used in the USGS 3-second database
    is based on the World Geodetic System 1972 (WGS‑72) ellipsoid and
    the corresponding1983 North American Datum (NAD‑83). All coordinates
    used in carrying out the analyses required in this methodology,
    appearing in applications for response station hubs, and reported in
    the files required to be submitted or served in conjunction with
    such applications shall be based upon use of NAD‑83. It should be
    noted that the Commission historically required use of NAD‑27 for
    applications in the MDS and ITFS services and that the values in the
    FCC's database have been based upon use of NAD‑27. As of the opening
    of the one-week filing window for applications for response station
    hub licenses, the Commission will accept only coordinates based upon
    use of NAD‑83 for applications for all classes of stations in these
    services. Those following this methodology or filing applications
    for any other purpose in these services are advised that NAD‑27 data
    from previously existing sources must be converted to NAD‑83 in
    order to carry out the requirements specified herein and in the
    related Rules.[^1]

## Defining Regions and Classes for Analysis

17. To provide flexibility in system design, regions may optionally be
    created within response service areas. Regions may be of arbitrary
    size, shape, and location. The territory within a region must be
    contiguous. Regions within a single RSA shall not overlap one
    another. Within regions, response stations are apt to be randomly
    distributed and for analysis purposes are to be assumed to be
    uniformly distributed. Except as described in the next paragraphs,
    regions are to be defined by their boundaries in the same manner as
    are response service areas. (For details on describing boundaries,
    see the section above on Defining Grid of Points for Analysis.)

18. It is permissible to define regions that are nested circular areas.
    In this case, the innermost region will truly be circular. The
    remaining regions will be annular rings having an inner and an outer
    radius. The inner radius will be the outer radius of the region just
    inside the particular region. The outer radius will be that
    specified in the File Format for the region under consideration.
    Nested regions will be determined by their having identical center
    points. Circular regions can be specified that fall within other
    regions and subtract from them but that do not share a common center
    point; in these situations, the non-circular geographic boundary
    definitions method must be used, as discussed in the next paragraph.

19. It is also permissible to define regions that are nested
    non-circular areas. In this case, one region must be completely
    contained within another. The normal procedure for defining each
    region using pairs of coordinates shall be followed. Grid points
    that are within the inner region shall be ascribed to it, while grid
    points outside the inner region shall be ascribed to the outer
    region. It is permissible to define multiple inner regions that
    either are nested within one another or that are separate from one
    another. Nested regions must be completely contained within the next
    outer regions; separate regions may touch one another but may not
    overlap.

20. It is further permissible to define regions that, in total, do not
    completely cover the area of the associated RSA. The regions
    involved in this situation can be either circular or non-circular.
    Any portion of the RSA not covered by a defined region shall be
    ascribed to Region 00, and at least one class of station also shall
    be assigned to Region 00 if it exists. Thus grid points that fall
    between non-concentric circular regions, that fall between defined
    non-circular regions, or that fall outside the largest of a
    concentric group of regions would all be ascribed to Region 00.
    Region 00 would then be treated in the same fashion as any other
    region insofar as the association of classes of stations, the
    definition of grid points, and the like.

21. Within each region, at least one class of response station with
    defined characteristics must be specified to match the interference
    predicted to be caused with the types of installations to be made.
    The classes are to be used in interference analyses and to provide
    limitations on the installations that may be made in the related
    region. The characteristics of each such class of response stations
    shall include the maximum height above ground level (AGL) for
    antennas, the maximum equivalent isotropic radiated power (EIRP),
    and the combined worst-case antenna radiation pattern -- for each
    polarization when both are used -- for all response stations of that
    class to be installed. When response stations share a channel by
    transmitting simultaneously (see section below on Determining
    Transmitter Configuration), for each class of response stations
    within each region, the maximum number of such response stations
    that may transmit simultaneously on any channel or sub-channel shall
    be specified.

22. Specification of the maximum number of simultaneously transmitting
    response station transmitters shall be on a power spectral density
    basis. The number to be specified is the number of transmitters that
    may simultaneously operate within any portion of the channel, no
    matter how finely divided. The maximum EIRP that may be emitted by
    any individual response station must be limited proportionately to
    the fraction of the channel that the response station occupies,
    resulting in a maximum radiated power spectral density (as expressed
    in dBm/m^2^/Hz) that is constant across the channel. The total
    number of individual response stations that may operate within a
    licensed channel at any one instant will depend upon the
    subchannelization scheme used. For example, if an entire 6 MHz
    channel is dedicated to response station operation and if the
    maximum number of simultaneously transmitting stations within a
    response station hub antenna sector is specified as 50, then 50
    response stations could all occupy the entire channel at the
    specified maximum EIRP. On the other hand, if the 6 MHz channel were
    divided into ten sub-channels of 600 kHz each, then each sub-channel
    could support 50 response stations, for a total of 500, each
    transmitting with a maximum of one-tenth the specified maximum EIRP.
    Carrying the example one step further, the same 6 MHz channel could
    simultaneously support 10 response stations using the entire channel
    width and full specified EIRP and also 40 response stations on each
    of 10 sub-channels, totaling 400, each transmitting with one-tenth
    the specified maximum EIRP, for a grand total of 410 simultaneously
    operating response stations. The subchannelization scheme may be
    changed without notice to the Commission or to other licensees so
    long as values, i.e., actual and equivalent, specified for the total
    number of stations and the radiated power spectral density (in
    dBm/m^2^/Hz) are not exceeded at any time for any portion of the
    channel.

23. The combined worst-case antenna azimuth radiation pattern is
    required to be specified collectively for all of the classes of
    response stations located at each grid point (in the procedure
    above, in the section on Defining Grid of Points for Analysis, for
    confirming that the required number of grid points is specified) and
    individually for each of the classes defined for each region of the
    RSA. In the case of the collective pattern used to determine
    adequacy of the number of grid points, if both polarizations are
    used in the system, the horizontally- and vertically-polarized
    azimuth patterns of each antenna should be treated as deriving from
    separate antennas and should be combined with one another and with
    the patterns from all the other antennas at that grid point. In the
    cases of the individual patterns for each class used for
    interference analyses, if both polarizations are used in the system,
    the horizontally- and vertically-polarized combined worst-case
    azimuth patterns should be determined separately for all classes
    defined. Similarly, the cross-polarized worst-case patterns should
    be determined for each polarization.

24. These combined worst-case patterns are derived by setting the
    maximum forward signal power of all antenna types to be used within
    the class or classes to the same value and then using the highest
    level of radiation in each direction from any of the antennas as the
    value in that direction for the combined antenna pattern. The same
    method is used to determine both plane- and cross-polarized
    patterns, which are used separately in interference analyses. The
    combined worst-case plane- and cross-polarized patterns for each
    class will be used in all of the interference studies and are not to
    be exceeded in actual installations of response stations within a
    class to which the pattern applies.

## Determining System Configuration

25. Several factors in the configuration of a system determine whether
    or not transmitters located at specific grid points could cause
    interference to particular neighboring systems. In order to simplify
    the study of interference to those neighbors, the system
    configuration is taken into account so as to reduce the number of
    calculations required by eliminating the study of interference from
    specific grid points when possible. The main factor that determines
    whether to eliminate certain grid points from consideration is
    terrain blockage.

26. When grid points are completely blocked from line-of-sight to all of
    a neighboring system, they can be eliminated from the aggregation of
    power used in calculating interference to that system. To determine
    whether to eliminate a grid point for this reason, a shadow study
    can be conducted from each grid point in the direction of the
    neighboring system. Separate studies can be conducted for classes of
    response stations that have different maximum heights above ground.
    If there is no area within the protected service area and no
    registered receiving location of the neighboring system to which a
    particular class of station at a grid point has line-of-sight, it
    can be eliminated from the calculations that determine the power of
    interfering signals at the neighbor's location. Alternatively, lack
    of line-of-sight can be evaluated from each class at each grid point
    to each location analyzed within the neighboring system (see section
    below on Calculating Aggregated Power from Transmitters), and grid
    points can be eliminated on a location-by-location basis, if that
    process is more easily implemented. (It should be noted that
    elimination from analysis of grid points not having line-of-sight
    effectively also eliminates activation for undesired response
    station signals of the non-line-of-sight \[NLOS\] mode by the
    propagation model defined later. The NLOS mode can still be
    activated for desired signals by the model in the various required
    analyses of interference to neighboring systems.)

27. There are two ways in which a large number of response stations can
    share channels: They can take turns using the channels so that only
    one transmitter will be turned on at any particular instant on each
    channel or sub-channel being received by a separate receiver in the
    system (commonly called TDMA), or they can transmit at the same time
    and use special filtering techniques at the receiver to separate the
    signals they are sending simultaneously to that receiver (commonly
    called CDMA). These two cases will result in different levels of
    power being radiated into neighboring systems, and therefore they
    must be analyzed slightly differently.

28. In the case of response stations that take turns using a channel or
    sub-channel, the grid point and class of station that produces the
    worst case of interference to each analyzed location in the
    neighboring system must be determined for each group of response
    stations that share a channel (e.g., within a response station hub
    receiving antenna sector). In this case, the interfering signal
    source can be treated as a single transmitter occupying the full
    bandwidth of the channel or sub-channels used from that location and
    having a power level equal to the aggregate of the power transmitted
    on all of the sub-channels, if sub-channels are used.

29. In the case of response stations that simultaneously share a channel
    or sub-channel, the grid point and class of station that produces
    the worst case of interference to each analyzed location in the
    neighboring system must be determined for each group of response
    stations that share a channel (e.g., within a response station hub
    receiving antenna sector). In this case, the interfering signal
    source can be treated as a single grid point at which are located
    all of the simultaneously transmitting transmitters, occupying the
    full bandwidth of the channel or sub-channels used from that
    location, and having a power level equal to the aggregate of the
    power transmitted by all of the response stations transmitting
    simultaneously on all of the sub-channels, if sub-channels are used.

30. In cases of shared-channel operation in which the number of
    simultaneously transmitting response stations of a class is limited
    by a region that crosses sector boundaries, the number of such
    response stations considered within some sectors may be limited so
    that the total included in the analysis in all sectors does not
    exceed the total permitted for the region. The objective in
    analyzing these cases is to find the worst case situation with
    regard to the maximum number of simultaneously transmitting
    transmitters, assigning them collectively to the locations at which
    they cause the most interference to each location analyzed within
    neighboring systems, while respecting the limits imposed on the
    number of such transmitters by sector and by region. A statement
    describing in detail the process or algorithm followed in selecting
    the number and classes of response stations analyzed at each grid
    point shall be appended to the application and distributed as a
    standard ASCII text file along with the data file described below in
    the section on the File Format.

31. An example of the case just described of shared-channel operation
    with the number of simultaneously transmitting transmitters limited
    both by region and by sector is one in which a region comprises an
    annular ring that stretches from half the radius to the full radius
    of a circular RSA. The region has a limit of 200 simultaneously
    transmitting transmitters of a particular class, and each of 20
    sectors is limited to 20 simultaneously transmitting transmitters.
    If the worst case interference from each sector were caused by the
    subject class and all were used in analyzing interference to a
    neighboring system, the result would be the use of 400 such response
    stations (20 x 20) in the analysis, while the region is limited
    to 200. Consequently, the 10 regions (10 x 20 meets the limit
    of 200) causing the most interference to the neighbor would be
    selected, and, in the other 10 sectors, the classes of station
    causing the second largest amount of interference to the neighbor
    would be selected for use in the analysis. In choosing the secondary
    interfering response station classes, the same type of limitations
    would have to be observed. The process for making these selections
    based on the appropriate limitations would have to be followed for
    each analyzed point in the neighboring system.

## Calculating Aggregated Power from Transmitters

32. The final major step in calculating interference from response
    station transmitters is the calculation of the equivalent isotropic
    radiated power (EIRP) to be attributed to each of the selected grid
    points in the various interference studies so as to be
    representative of the number of response stations that are expected
    to be in operation simultaneously within the RSA. When analyzing
    systems in which the response stations take turns using a channel or
    sub-channels, this means, for each location analyzed in the system
    to be protected, selecting the grid point and class of station
    within each sector that radiates the strongest signal to that
    location and aggregating the power from all such selected grid
    points and classes, using the maximum EIRP (for all sub-channels
    taken together), the maximum antenna height, and the worst case
    antenna pattern for a single station of that class at each selected
    grid point.

33. For systems in which response stations simultaneously share the
    channel or sub-channels to each receiver at each hub, substantially
    the same analysis is performed. The difference is that the maximum
    number of simultaneously transmitting response stations within each
    sector is placed at each selected grid point, in turn. The maximum
    EIRP (for all sub-channels taken together) for each regional class
    at each grid point, expressed in dBW, is converted to Watts. The
    EIRP is then multiplied by the number of simultaneously transmitting
    transmitters in the regional class assigned to that grid point, and
    the resulting EIRP in Watts is converted back to dBW. When the
    number of simultaneously transmitting transmitters within a sector
    in the class and at the grid point that causes the most signal to be
    propagated to a location in the neighboring system does not equal
    the number of simultaneously transmitting transmitters permitted in
    that sector, the grid point and class of station that cause the next
    largest amount of signal to be so propagated shall be used to
    account for the remaining number of simultaneously transmitting
    transmitters permitted in the sector, and so on as necessary. At
    each location analyzed within the neighboring system, the power
    received from the selected grid points within each sector is
    aggregated through conversion from dBW to Watts, addition of power
    levels, and conversion back to dBW. In each case, the values so
    calculated are the aggregated powers of all the simultaneously
    transmitting response station transmitters sharing the same
    channel(s) or sub-channel(s), from all sectors, for use as the
    undesired signal levels in interference analyses.

34. In calculating the aggregate EIRP or received signal power, the
    interfering signals may be treated as emanating from response
    stations occupying the full channel and utilizing the maximum
    allowed EIRP. In practice, as described previously in the section on
    Defining Regions and Classes for Analysis, subchannelization may be
    used so long as the power spectral density limits are respected.
    Interference protection may also be calculated using appropriate
    adjustments to the required protection ratios based on the relative
    bandwidths of the desired and undesired signals. In either case, the
    maximum number of simultaneously transmitting response stations
    shall be limited on a power spectral density basis to the number
    specified.

35. In a system using both polarizations, the response stations
    represented by each grid point are to be assumed to use the
    polarization of the response station hub antenna sector in which
    they are located. The appropriate horizontal or vertical combined
    worst-case antenna pattern is to be used in interference studies
    depending upon the polarization of the sector in which each grid
    point is located. In a system using only one polarization, the
    effect of antenna sectors can be ignored and the choice between
    horizontal and vertical polarization patterns made identically for
    all grid points.

36. Finally, the aggregate power of each active regional class at each
    active grid point is used in conducting the required interference
    studies described in the relevant Rules. For this purpose, a study
    grid is established in each neighboring system to be evaluated. The
    study grid is constructed in a manner similar to that for the grid
    of points within the RSA. First, a reference point must be
    established for the 35-mile Protected Service Area, Basic Trading
    Area (BTA), or Partitioned Service Area to be studied. For a 35-mile
    Protected Service Area, the reference point is either the
    transmitter location or the pre-established FCC reference point if
    the transmitter has been moved. For a BTA or Partitioned Service
    Area, the reference point is the point, measured in degrees,
    minutes, and seconds (to the nearest one-tenth second), that is
    midway between the eastern- and western-most extremes of the BTA and
    midway between the northern- and southern-most extremes of the BTA
    or Partitioned Service Area. (It should be noted that, depending
    upon the shape of the BTA or Partitioned Service Area, the reference
    point might fall outside the BTA or Partitioned Service Area.) Next
    a series of orthogonal east-west and north-south lines is
    constructed having 1.5 km spacing. The lines surrounding the
    reference point shall be located 0.75 km from the reference point at
    their nearest points to the reference point. The east-west lines
    shall be parallel to the lines of latitude. Where there is an
    overlap between the RSA and the Protected Service Area, BTA, or
    Partitioned Service Area to be studied, additional lines may be
    used, spaced equidistant from one another and from the 1.5 km-spaced
    lines (i.e., lines with a spacing in km of 0.75, 0.5, 0.375, 0.25,
    etc). The study points shall be at the intersections of the
    orthogonal line structure.

37. Signals from the potentially interfering system shall be evaluated
    at the study points. The signal level at each of the study points is
    calculated using the terrain-based propagation analysis tool
    specified below to determine the signal level incident at that point
    from each regional class at each grid point within an RSA. The
    signals from the potentially interfering system to be evaluated are
    the aggregate of the signals from all RSAs within the system. In
    addition, if the channels are partially or completely shared with
    primary or booster transmitters, the interference contributions of
    those stations must be aggregated with those of the response
    stations. Signal aggregation is performed by first converting
    dBW/m^2^ to W/m^2^, adding the power levels obtained, and converting
    from W/m^2^ back to dBW/m^2^. If the system under study is a 35-mile
    Protected Service Area, then the relevant D/U ratios must be
    obtained or the appropriate minimum signal levels protected when the
    desired signal falls below a prescribed threshold. (That threshold
    is described in the next paragraph.) For a Protected Service Area,
    the directional characteristics of the FCC reference antenna are
    applied to each of the incident signals prior to aggregation. If the
    system under study is a BTA or Partitioned Service Area, then the
    signal level at all study points within the BTA or Partitioned
    Service Area must meet the --73 dBW/m^2^ requirement, and the
    directional characteristics of the FCC reference antenna are not
    applied, as the antenna characteristics in this instance are
    irrelevant.

38. In conducting analyses of interference from response, booster,
    and/or primary stations included in two-way systems to neighboring
    35-mile Protected Service Areas or registered receive sites,
    neighboring receivers shall be protected by the appropriate D/U
    ratio so long as the desired signal exceeds a defined signal level,
    but lower signal levels need be protected only to a minimum level
    that depends upon the frequency relationship between the signals.
    For co-channel desired signals below 45 dB S/N, the defined signal
    level shall be deemed protected when the undesired signal is at or
    below the noise floor level for the bandwidth involved, as
    calculated per Equation 2 below. For adjacent channel desired
    signals below 45 dB S/N, the defined signal level shall be deemed
    protected when the undesired signal is at or below 45 dB above the
    noise floor. Thus for a 6 MHz channel, the minimum co-channel
    undesired signal level that must be maintained would be ‑136.2 dBW
    or ‑106.2 dBm; the minimum adjacent channel undesired signal level
    that must be maintained would be --91.2 dBW or --61.2 dBm. These
    studies shall be conducted based exclusively upon the levels of the
    desired and undesired signals without consideration of the receiver
    noise figure.

39. Similar methods shall be used in conducting the various
    desired-to-undesired (D/U) signal ratio studies for co-channel and
    adjacent channel interference.[^2] In all of these studies, the
    analysis shall use the aggregate power of each regional class at
    each grid point, the worst case plane- or cross-polarized antenna
    pattern, as appropriate, for each regional class, with the antennas
    at each grid point aimed toward the response station hub, and the
    maximum antenna height above ground specified for each regional
    class at each grid point.

# Protection to Response Station Hubs

40. The applicant for a new or modified main station, high-power booster
    or response station hub is required to demonstrate protection to any
    previously proposed or licensed response station hub within 160.94
    km (100 miles) of the proposed facilities. Two methods are available
    for demonstrating such protection. The applicant can demonstrate
    that the proposed facility will not increase the effective power
    flux density of the undesired signals generated by the proposed
    facility and any associated main stations, booster stations or
    response stations at the response station hub antenna for any
    sector. Alternatively, the applicant can demonstrate that the
    proposed facility will not increase the noise floor at the response
    station hub antenna for any sector by more than 1 dB for co-channel
    signals and 45 dB for adjacent channel signals. The applicant can
    invoke the alternative protection method only once per response
    station hub sector. The methods to be used in making such
    demonstrations follow.

41. As is discussed in the section below on the File Format, an
    applicant for a response station hub will have specified the
    geographic coordinates of the hub location and, for each sector,
    (1) the height of the antenna above ground level (AGL) and above
    mean sea level (AMSL), (2) the hub receiving antenna pattern (both
    in azimuth and elevation, both co- and cross-polarized), (3) the hub
    receiving antenna gain in the main lobe (in dBi), (4) the azimuth of
    the main lobe, (5)  any mechanical tilt utilitized, (6) the
    direction of any mechanical tilt utilized, and (7) the polarization
    of the receiving antenna. Those specified characteristics shall be
    utilized for purposes of demonstrating interference protection to
    the hub.

42. The level of interference caused to a response station hub by the
    aggregate power of the proposed new or modified MDS or ITFS facility
    and any associated main stations, booster stations, and response
    stations shall be independently determined for each sector. The
    resulting summation is then used for comparisons between old and new
    values when the applicant is attempting to demonstrate that the
    effective power flux density of the undesired signals has not
    increased, or for comparison against the specified receiver
    degradation threshold when the applicant is attempting to
    demonstrate that the proposed facility will not increase the noise
    floor by more than the permissible amount.

43. In calculating the effective power flux density value, the effective
    isotropic radiated power (EIRP) radiated in the direction of the
    protected response station hub from each associated main, booster,
    and/or response station (as represented by the selected grid points
    described earlier in the section Four Major Steps for Response
    Station Interference Analysis) of the applicant shall first be
    determined. The power arriving at the response station hub shall be
    analyzed using the propagation analysis tool described in the
    following section on that subject. The propagation model will select
    between the line-of-sight (LOS) and non-line-of-sight (NLOS) modes
    described later for each interfering signal when making the required
    analyses. The aggregation of power from all related sources shall
    take account of the angular displacement of each particular source
    from the peak of the main lobe of the receiving antenna and the
    relative polarization of each interfering signal source.

44. To determine the effective power flux density, the following formula
    shall be used:

\(1\)

Where ![](media/image1.wmf){width="5.138888888888889in" height="1.25in"}

45. When the applicant is attempting to demonstrate that its proposed
    facility and all its associated facilities will not increase the
    effective power flux density of the undesired signals at each
    response station hub sector antenna, it is necessary to ascertain
    that the predicted effective power flux density from the proposed
    facility and all associated facilities does not exceed the value
    predicted from any previously authorized associated facilities at
    each response station hub sector antenna. When the applicant is
    attempting to demonstrate that the proposed facility and all
    associated facilities will not impermissibly increase the noise
    floor, an additional step is required to ascertain that the
    predicted value of the effective power flux density does not exceed
    the allowed threshold values for both co-channel and adjacent
    channel signals.

46. To calculate the relationship of the effective power flux density to
    the threshold values for co-channel and adjacent channel signals,
    the level of the noise floor of the hub receiver first must be
    figured. It is given by the formula:

![](media/image2.wmf){width="2.2916666666666665in"
height="0.2361111111111111in"} (2)

Where ![](media/image3.wmf){width="3.8055555555555554in"
height="0.8333333333333334in"}

47. With a typical noise temperature of 17.2 deg. C and a bandwidth of 6
    MHz, Equation 2 yields a thermal noise power of -136.2 dBW.

48. Factors in the calculation of the equivalent power flux density of
    the thermal noise power are the noise figure of the receiver input
    stage(s) and the cable losses between antenna and receiver input.
    For consistency, the noise figure shall be set at 2.5 dB, and the
    cable losses shall be set at 1 dB. The wavelength of the received
    signal also becomes a factor; it shall be expressed in meters and
    can be taken as 0.13915 meters for the 2.150-2.162 GHz band and as
    0.11538 meters for the 2.5-2.7 GHz band. The equivalent total power
    flux density of the thermal noise power plus the effective power
    flux density of the interfering signal(s) then is given by:

![](media/image4.wmf){width="4.027777777777778in"
height="0.9166666666666666in"} (3)

Where ![](media/image5.wmf){width="5.125in"
height="1.0555555555555556in"}

49. When applicants invoke the alternative hub protection method by
    demonstrating protection to the noise floor of a response station
    hub, compliance with the limits for co-channel and adjacent channel
    interference from the proposed facilities to the response station
    hub can be determined by first calculating the equivalent total
    power flux density with the effective power flux density of the
    interference set to zero and then re‑computing using the true
    effective power flux density. (To be mathematically correct in
    setting the interference value to zero, either the first term inside
    the parentheses in Equation 3 can be set to zero, or the *PFD~EFF~*
    value can be set to a very low value --- at least 30 dB below
    *P~THERMAL~*.) The two values found should not differ by more than
    1 dB for co-channel interference nor by more than 45 dB for adjacent
    channel interference.

# Propagation Model

50. When analyzing interference from or to any response, booster, or
    primary stations included in two-way systems to or from other
    stations, the propagation model described below shall be used,
    taking into account the effects of terrain and certain other
    factors. The model is derived from basic calculations described in
    NTIS Technical Note 101.[^3] It is intended as a tool for analysis
    of wide area coverage of microwave transmissions, and it is
    available built into commercial propagation analysis software
    packages that are widely used by the MDS/ITFS industry for coverage
    and interference prediction.[^4]

51. In the model described, two loss terms are computed --- the free
    space path loss based solely on distance and the excess path loss
    (XPL) that derives from terrain obstacles and other elements in the
    environment. Among the inputs required for some implementations of
    the model are location and time variability factors. Other factors
    for such items as clutter and foliage losses can be considered by
    some software versions, but they will not be used in analyzing the
    systems considered herein.

52. The excess path loss portion of the calculation considers several
    conditions that impact signal propagation. These include whether the
    path is "line of sight" for the direct ray, whether there is 0.6
    first Fresnel zone clearance, or whether the path is totally
    obstructed. When the first Fresnel zone is partially obstructed, an
    additional loss up to 6 dB is included by the model. When the path
    is totally obstructed, the path loss is calculated using the
    Epstein-Peterson method[^5] that considers the diffraction losses
    over successive terrain obstacles. In this case, each obstacle is
    treated separately, with the preceding obstacle (or the transmitter,
    in the first instance) considered to be the transmitter and the
    succeeding obstacle (or the receiver, in the last instance)
    considered to be the receiver.

53. Some software implementations of the methods described herein may
    provide for setting parameters for both location and time
    variability in terms of the percentage of the locations or of the
    time that signals meet or exceed studied levels. For purposes of
    analyzing the interference from response stations and to response
    station hubs, both the location and the time variability factors
    shall be set to 50 percent in all cases. When available as a
    parameter, the confidence level shall be set to 50 percent.

54. The methods defined in this Propagation Model require the
    establishment of geographic lines between paired transmitter and
    receiver locations, with elevation values determined at sample
    points along the lines. For consistency in implementation, the
    locations of the sample points along each line are defined to be
    spaced at 0.25 km intervals, beginning from the transmitter location
    and ending at the 0.25 km point just prior to the actual receiver
    location. The study itself shall end at the actual receiver
    location. The elevation of points along the line shall be obtained
    through bilinear interpolation of the elevation values of the
    surrounding four grid levels of the USGS 3-second database.

## Propagation Model Outline

55. For the purposes of this Methodology, the propagation model has
    three basic elements that affect the predicted field strength at the
    receiver:

> 1\) Line-of-Sight (LOS) mode, using basic free-space path loss
>
> 2\) Non-line-of-sight (NLOS) mode, using multiple wedge diffraction
>
> 3\) Partial first Fresnel zone obstruction losses applicable to either
> mode

56. The LOS and NLOS modes are mutually exclusive --- a given path
    between a transmitter and a receiver is either LOS or not. The
    fundamental decision as to whether a path is LOS is based on the
    path geometry. That decision is described in the next subsection,
    which also defines the LOS mode for the model.

## Line-of-Sight (LOS) Mode

57. The determination of whether a path between a transmitter and a
    receiver is LOS is made by comparing the depression angle of the
    path between the transmitter and receiver with the depression angle
    to each terrain elevation point along the path. The depression angle
    from transmitter to receiver is computed using an equation of the
    form:

\(4\)

where:

is the depression angle relative to horizontal from the transmitter to
the receiver\
in radians

is the elevation of the transmit antenna center of radiation above mean
sea level\
in meters

is the elevation of the receive antenna center of radiation above mean
sea level\
in meters

is the great circle distance from the transmitter to the receiver in
meters

*a* is the effective earth radius in meters taking into account
atmospheric refractivity

58. The atmospheric refractivity is usually called the K factor. A
    typical value of K is 1.333, and using the actual earth radius of
    6340 kilometers, *a* would equal 8451 kilometers, or 8,451,000
    meters. For the purpose of these Rules, K = 1.333 shall be used.

59. Using an equation of the same form, the depression angle from the
    transmitter to any terrain elevation point can be found as:

\(5\)

where:

is the depression angle relative to horizontal for the ray between the
transmitter and the point on the terrain profile

is the elevation of the terrain point above mean sea level in meters

is the great circle path distance from the transmitter to the point on
the terrain path in meters

are as defined above following Equation (4).

60. The variable is calculated at every point along the path between the
    transmitter and the receiver and compared to . If the condition is
    true at any point, then the path is considered NLOS and the model
    formulations in the subsection on Non-Line-of-Sight (NLOS) Mode
    below are used. If is true at every point, then the
    transmitter-receiver path is LOS and the formulations in this
    subsection apply.

61. For LOS paths, if the geometry is such that a terrain elevation
    point along the path between the transmitter and receiver extends
    into the 0.6 first Fresnel zone, then an additional loss ranging
    from 0 to 6 dB is included for partial Fresnel zone obstruction.
    This calculation is presented next.

### Attenuation Due to Partial Obstruction of the Fresnel Zone

62. When a path is LOS but terrain obstacles are close to obstructing
    the path, additional attenuation will occur. This attenuation due to
    a "near miss" of obstacles on the path can be taken into account by
    including a loss term in the LOS formulation which is based on the
    extent to which an obstacle penetrates the first Fresnel zone. From
    diffraction theory, when the ray just grazes an obstacle, the field
    on the other side is reduced by 6 dB (half the wavefront is
    obstructed). When the clearance between the obstacle and the ray
    path is 0.6 of the first Fresnel zone, the change in the field
    strength at the receiver is 0 dB, and with additional clearance a
    field strength increase of 6 dB can occur owing to the in-phase
    contribution from the ray diffracted from the obstacle. For
    additional clearance, an oscillatory pattern in the field strength
    occurs.

63. In the model described, if the ray path clears intervening obstacles
    by at least 0.6 of the first Fresnel zone, then no adjustment to the
    receiver field will occur. For the case when an obstacle extends
    into the 0.6 first Fresnel zone, a loss factor ranging from 0 to 6
    dB is applied based on a linear proportion of how much of the 0.6
    First Fresnel zone is penetrated. This Fresnel zone path loss or
    attenuation term can be written as:

\(6\)

where:

is the height difference in meters between the ray path and the terrain
elevation at distance along the path

is the 0.6 first Fresnel zone radius at distance along the path

64. The values and are calculated taking into account the effective
    earth radius using the K factor. The 0.6 first Fresnel zone radius
    is given by

![](media/image6.wmf){width="2.638888888888889in"
height="0.6111111111111112in"} meters (7)

where is the frequency in MHz and all distances are in kilometers.

65. The use of the partial Fresnel zone obstruction loss from 0 dB at
    0.6 clearance to 6 dB at grazing also provides a smooth transition
    into the NLOS mode in which knife-edge diffraction loss just below
    grazing will start at 6 dB and increase for steeper ray bending
    angles to receiving locations in the shadowed region. Note that this
    attenuation factor is found only for the terrain profile point that
    extends farthest into the 0.6 first Fresnel zone, not for every
    profile point which extends into the 0.6 first Fresnel zone.

### Summary of Calculation of Field Strength at the Receiver Under LOS Conditions

66. The formulations for computing the field strength at the receiver
    under LOS conditions can be summarized with the following equation:

![](media/image7.wmf){width="3.111111111111111in" height="0.25in"} (8)

where *E~r~* is the field strength at the receiver in dBµV/m, *d~r~* is
the distance from transmitter to receiver in kilometers, and is the
partial Fresnel zone obstruction loss from Equation (6). The term is the
equivalent isotropic radiated power (EIRP) in dBW in the direction of
the receiver.

67. In terms of path loss between two antennas with gains of 0 dBi in
    the path direction, Equation (8) can be written as:

![](media/image8.wmf){width="3.236111111111111in" height="0.25in"} (9)

where *L~LOS~* is the line-of-sight path loss in dB, *f* is frequency in
MHz, and *d~r~* is the distance from transmitter to receiver in
kilometers.

## Non-Line-of-Sight (NLOS) Mode

68. The mechanism for deciding when to use the LOS mode and when to use
    the NLOS mode is described at the beginning of the subsection on
    Line-of-Sight Mode above. When the model elects to use the NLOS
    formulations to follow, it means that one or more terrain or other
    features obstructs the ray path directly from the transmitter to the
    receiver. In this case, the free space field strength is further
    reduced for the attenuation caused by the obstacles. For the model
    defined here, the calculation of obstruction loss over an obstacle
    is done by assuming the obstacle is a perfect electrical conductor
    rounded obstacle with a height equal to the elevation of the
    obstruction and a radius equal to 1 meter. This approximation has
    been shown to be effective in modeling hills and other terrain
    obstructions, which do not behave as knife edges in practice.
    Diffraction loss in this model is calculated assuming individual
    obstacles on the path can be modeled as isolated rounded obstacles.
    The losses from multiple isolated obstacles are then combined.

### Diffraction Loss

69. The loss over an individual rounded obstacle is primarily a function
    of the parameter that is related to the path clearance over the
    obstacle. The total diffraction loss, , in dB, is the sum of three
    parts --- , and . The equations to calculate the total and the three
    parts are given below:

\(10\)

for (11)

![](media/image9.wmf){width="2.0277777777777777in" height="0.25in"} for
(12)

![](media/image10.wmf){width="1.9583333333333333in" height="0.25in"} for
(13)

![](media/image11.wmf){width="3.0965277777777778in" height="0.25in"}
(14)

![](media/image12.wmf){width="3.4305555555555554in" height="0.25in"} for
(15)

for (16)

for ![](media/image13.wmf){width="0.4861111111111111in"
height="0.2222222222222222in"} (17)

where the curvature factor is

![](media/image14.wmf){width="2.1805555555555554in"
height="0.5555555555555556in"} (18)

70. The obstacle radius *R* and the distances *d, d~1~, and d~2~* are in
    kilometers, and the frequency *f* is in MHz. The distance term *d*
    is the path length from the transmitter (or preceding obstacle) to
    the receiver (or next obstacle), is the distance from the
    transmitter (or preceding obstacle) to the obstacle, and is the
    distance from the obstacle to the receiver (or next obstacle). When
    the radius is zero, the obstacle is a knife-edge, and .

71. The parameter in the equations above takes into account the geometry
    of the path and can be thought of as the bending angle of the radio
    path over the obstacle. It is computed as:

\(19\)

Figure 1. Geometry for computing where *d* is the path length from the
transmitter (or preceding obstacle) to the receiver (or next obstacle),
![](media/image15.wmf){width="0.16666666666666666in"
height="0.1527777777777778in"} is the angle relative to a line from the
transmitter (or preceding obstacle) to the receiver (or next obstacle),
and is the angle relative to a line from the receiver (or next obstacle)
to the transmitter (or preceding obstacle). The distance *d* and the
wavelength ![](media/image16.wmf){width="0.1527777777777778in"
height="0.19375in"} are in the same units as one another, e.g.,
kilometers. The definitions of and are shown in Figure 1. For the
multiple obstacle case, obstacles are treated successively as
transmitter-obstacle-receiver triads to construct the path geometry and
bending angle over each obstacle. The value of *v* is then used to
calculate the diffraction loss over each obstacle. The resulting
obstacle losses are summed to arrive at the total obstacle diffraction
loss for the path.

### Summary of Calculation of Field Strength at the Receiver Under NLOS Conditions

72. The field strength at the receiver in the NLOS mode can then be
    written as:

![](media/image17.wmf){width="3.0416666666666665in"
height="0.2638888888888889in"} (20)

where *E~r~* is the field strength at the receiver in dBµV/m, *d~r~* is
the distance from transmitter to receiver in kilometers, and is the
equivalent isotropic radiated power (EIRP) in dBW in the direction of
the receiver. The term is defined as:

![](media/image18.wmf){width="1.2222222222222223in"
height="0.4861111111111111in"} dB (21)

where is defined in Equation (10) and *n~obs~* is the number of
obstructions in the path.

73. The corresponding path loss between antennas with 0 dBi gain in the
    path direction can be written as:

\(22\)

where *L~NLOS~* is the non-line-of-sight path loss in dB, *f* is
frequency in MHz, and *d~r~* is the distance from transmitter to
receiver in kilometers.

# File Format

74. To facilitate the exchange of data on two-way MDS and ITFS systems
    permissible under Parts 21 and 74, a file format is herein described
    for the submission of requisite technical data to be provided to the
    Commission and to all parties that must be served with notice of the
    applications and/or engineering studies. The media shall be either
    3½-inch floppy disks or CD‑ROMs. The media and basic formatting of
    that media are defined either by ISO/IEC Standards 9293,[^6]
    9529-1,[^7] and 9529-2[^8] for 3½-inch floppy disks[^9] or ISO
    Standard 9660[^10] for CD‑ROMs.

75. A file structured according to the file format shall be submitted
    individually for each Response Station Hub (RSH) and associated
    Response Service Area (RSA), i.e., there shall be only one RSH/RSA
    combination defined per file. It is permissible to store multiple
    such files on a single disk so long as each file is completely
    contained on a single disk, i.e., files may not span disks. In
    addition to the files structured according to the following format,
    each disk that contains a file describing an RSH/RSA combination
    that is part of a system shall include a copy of an Index File that
    lists all of the files related to the system. The Index File shall
    be in ASCII coding and shall list the file names, dates and times of
    storage, and sizes in bytes of the files associated with all the
    Response Station Hubs in the system. Furthermore, all the disks
    related to the system shall be labeled with their specific contents,
    including the data required in the Index File for the particular
    files contained on each disk. Each label shall also indicate the
    total number of disks in the series and the sequence number of the
    disk on which it appears. The Index File name shall consist of the
    name of the licensee or applicant (which may be abbreviated, but
    which must be consistently abbreviated in the same way by a single
    licensee or applicant) followed by a hyphen, followed by the name of
    the city where the system is located. This shall be followed by a
    decimal point and the extension "idx."

76. The remainder of this document outlines the format of technical
    information regarding each Response Service Area (RSA) to be
    submitted with each MDS/ITFS two-way application. The data shall
    appear in a number of sections for the purpose of grouping similar
    items within the file. Data shall be coded in an
    ASCII-formatted,[^11] comma-delimited file. Carriage return (0Dh)
    and line feed (0Ah) characters shall be placed at the end of each
    line in the file, as is normal when using standard text editors. To
    help in identifying data, where file sections are formatted as
    tables, the first entry in each row within a table shall be a
    sequence number indicating the position of the row within the table.
    To the extent possible, the sequence number shall be representative
    of the type of data contained on the row, such as the number of
    degrees of azimuth or elevation.

77. A generic example of the required file construction appears at the
    end of this section and may be used as a template for the submission
    of data. As shown there, section titles shall appear on a separate
    line in square brackets "\[ \]" and shall be separated from the
    preceding sections and from the data within their own sections by a
    blank line. Headers shall appear on the top line of the data
    contained within a section. Headers may contain data and may also
    help with both human and machine readability.

78. Units of measure that are to be utilized for all information
    supplied in the file are:

Latitude -- Degrees, Minutes, Seconds (DD,MM,SS.S) (to 1 decimal place
in seconds)[^12]

Longitude -- Degrees, Minutes, Seconds (DDD,MM,SS.S) (to 1 decimal place
in seconds)^12^

Azimuth or Bearing -- Degrees (to 1 decimal place)

Radius -- Kilometers (to 2 decimal places)

Ground Elevation -- Meters AMSL (to 0 decimal places)

Antenna Height -- Meters AGL (to 0 decimal places)

Electrical Beam Tilt -- Degrees (to 1 decimal place)

Mechanical Beam Tilt -- Degrees (to 1 decimal place)

Azimuth of Mechanical Beam Tilt -- Degrees (to 1 decimal place)

Power (EIRP) -- dBW (to 2 decimal places)

Antenna Gain -- dBi (to 2 decimal places)

Frequency -- MHz (to 3 decimal places)

1.  **General Information**

Section Title: "General Info"

> Entries: File Name
>
> Licensee/Applicant name
>
> City/State of hub location
>
> Coordinates of hub location
>
> Ground Elevation of hub location (meters)
>
> Call sign of station being modified/file number of application being
> amended
>
> City/State of station being modified

79. The File Name included in this section of the data file shall be the
    name originally given to the data file when it was created. This
    will assure that, even should the name of the data file be changed,
    it can be identified by its original name. It is this name that
    shall be included in the Index File required to appear on each disk
    of the set of files describing a complete system. The File Name
    shall be constructed from the call sign originally assigned for
    downstream service and modified for two-way upstream service
    followed by a hyphen, followed by a six-digit number giving the
    latitude of the RSH, followed by another hyphen, followed by a
    seven-digit number giving the longitude of the RSH. The name of the
    data file shall be completed by appending a decimal point followed
    by the extension "dat" to the name as defined above. When a file is
    updated as a result of modifications to a license or amendments to
    an application, the file name shall be modified by appending a
    hyphen and a letter before the decimal point and the extension. The
    letter shall be incremented with each successive revision to the
    file, beginning with "a" and progressing through "z." Should higher
    values be required, double letters "aa" through "zz" shall be used,
    incrementing the second letter and then the first. When a call sign
    for an existing downstream service does not exist, the identifier of
    the authorization document from the Commission assigning the subject
    channel to the applicant shall be used in its place.

80. The name either of the licensee or of the applicant, if not the
    licensee, filing the application with which the file is connected
    shall be included in the General Info section. The designation on
    the line that contains this information shall be either "Licensee"
    or "Applicant," as appropriate.

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2.  **Geographic Boundary Definitions -- Circular Areas**

Section Title: "Circular Geographic Areas"

Header: RSA Circular (0 or 1), Regions Circular (00 or RR, where RR =
total \# of circular regions)

> Entries: 00, RSA Reference Latitude, RSA Reference Longitude, RSA
> Radius (omit RSA Radius if RSA is non-circular)
>
> 01, Region 01 Center Latitude, Region 01 Center Longitude, Region 01
> Radius
>
> 02, Region 02 Center Latitude, Region 02 Center Longitude, Region 02
> Radius
>
> **:**
>
> **:**
>
> RR, Region RR Center Latitude, Region RR Center Longitude, Region RR
> Radius

81. The geographic area of an RSA or region may be described by a circle
    having a defined center point location and a radius. If the RSA is
    circular, then RSA Circular = 1, otherwise RSA Circular = 0.

82. If there are circular regions, then Regions Circular = the number of
    such regions, RR. Otherwise, Regions Circular = 00.

83. The RSA reference latitude and longitude are required in all cases
    and appear in this section for both circular and non-circular RSAs.
    If the RSA is non-circular, the radius is not given. Where the hub
    is outside the RSA, the reference point is that point, measured in
    degrees, minutes, and seconds (to the nearest one-tenth second),
    that is midway between the eastern- and western-most extremes of the
    RSA and also midway between the northern- and southern-most extremes
    of the RSA. It should be noted that the RSA reference point could
    fall outside the RSA itself.

84. Circular regions may share the same center point and have different
    radii, their circumferences thus forming concentric circles. In this
    situation, the circular region with the smallest radius extends from
    the center point to its circumference. All the other regions
    constitute annular rings, the inner radii of which are the outer
    radii of the center region or of the next inner rings and the outer
    radii of which are those listed for the region. When such concentric
    regions exist, they shall be listed in the order of increasing
    radius.

85. Circular regions may be defined having boundaries that extend beyond
    the boundary of the RSA. In such cases, the boundaries of the
    regions shall be deemed to be truncated (cut off) by the boundary of
    the RSA. Thus no grid points beyond the RSA boundary shall be
    considered in interference analyses, and no response stations beyond
    the RSA boundary shall be installed as a result of such a region
    definition.

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3.  **Geographic Boundary Definitions -- Non-Circular Areas**

> Section Title: "Non-Circular Areas"
>
> Header: RSA Non-Circular (0 or 1), Regions Non-Circular (00 or NN,
> where NN = total \# of non-circular regions),
>
> Entries: RSA Entry Title, \# of boundary points defining RSA (XXX)\
> RSA Latitude (001), RSA Longitude (001)\
> RSA Latitude (002), RSA Longitude (002)\
> RSA Latitude (003), RSA Longitude (003)\
> **:**\
> RSA Latitude (XXX), RSA Longitude (XXX)\
> Region RR+1 Entry Title, \# of boundary points defining region RR+1
> (AAA)\
> Region RR+1 Latitude (001), Region RR+1 Longitude (001)\
> Region RR+1 Latitude (002), Region RR+1 Longitude (002)\
> Region RR+1 Latitude (003), Region RR+1 Longitude (003)\
> **:\
> **Region RR+1 Latitude (AAA), Region RR+1 Longitude (AAA)\
> Region RR+2 Entry Title, \# of boundary points defining region RR+2
> (BBB)\
> Region RR+2 Latitude (001), Region RR+2 Longitude (001)\
> Region RR+2 Latitude (002), Region RR+2 Longitude (002)\
> Region RR+2 Latitude (003), Region RR+2 Longitude (003)\
> **:**\
> Region RR+2 Latitude (BBB), Region RR+2 Longitude (BBB)\
> **:\
> ** **:**\
> Region RR+NN Entry Title, \# of boundary points defining region RR+NN
> (ZZZ)\
> Region RR+NN Latitude (001), Region RR+NN Longitude (001)\
> Region RR+NN Latitude (002), Region RR+NN Longitude (002)\
> Region RR+NN Latitude (003), Region RR+NN Longitude (003)\
> , **:**\
> Region RR+NN Latitude (ZZZ), Region RR+NN Longitude (ZZZ)

86. The geographic descriptions of an RSA in the sections for Circular
    Areas (Section 2) and for Non-Circular Areas are mutually exclusive.
    One of them shall have the RSA indicator set to 1; the other shall
    be set to 0. When the Non-Circular Area RSA indicator is set to 0,
    the RSA list header and the list of RSA coordinates shall be
    omitted.

87. The reference point coordinates for both types of RSA are contained
    in the section on Circular Areas. Where the hub is outside the RSA,
    the reference point is that point, measured in degrees, minutes, and
    seconds (to the nearest one-tenth second), that is midway between
    the eastern- and western-most extremes of the RSA and also midway
    between the northern- and southern-most extremes of the RSA. It
    should be noted that the RSA reference point could fall outside the
    RSA itself.

88. Regions of both types, i.e., circular and non-circular, are
    permitted within a single RSA. Regions in this non-circular section
    shall be numbered sequentially continuing from the last region
    number in the circular section, i.e., from RR+1 to RR+NN, so that
    all regions have unique region numbers.

89. The data for the RSA and for the region boundary descriptions list
    pairs of latitude and longitude coordinates in sequence, with each
    group of data following an entry header. The entry header includes a
    title that numbers the area to which its data applies and a value
    indicating the number of entries in the list for its area.

90. Non-circular regions may be nested within one another, the inner
    regions subtracting from the areas covered by the outer regions. In
    this situation, a region with the smallest area extends to its
    perimeter. All other regions have voids where the inner regions are
    located. When such nested regions exist, they shall be listed in the
    order of increasing perimeter size of interior regions until the
    outermost region is reached.

91. Non-circular regions may be defined having boundaries that extend
    beyond the boundary of the RSA. In such cases, the boundaries of the
    regions shall be deemed to be truncated (cut off) by the boundary of
    the RSA. Thus no grid points beyond the RSA boundary shall be
    considered in interference analyses, and no response stations beyond
    the RSA boundary shall be installed as a result of such a region
    definition.

**4. Hub Sectorization Data**

Section Title: "Sectorization"

Header: \# of sectors within RSA (SS)

Entries: "Sector 01," Hub Receive Antenna Pattern #, Gain, Azimuth of
Main Lobe or Azimuth of Symmetry, Height AGL, Mechanical Beam Tilt,
Azimuth of Mechanical Beam Tilt, Polarization, Max Simultaneous
Transmitters

"Sector 02," Hub Receive Antenna Pattern #, Gain, Azimuth of Main Lobe
or Azimuth of Symmetry, Height AGL, Mechanical Beam Tilt, Azimuth of
Mechanical Beam Tilt, Polarization, Max Simultaneous Transmitters

**:**

**:**

"Sector (SS)," Hub Receive Antenna Pattern #, Gain, Azimuth of Main Lobe
or Azimuth of Symmetry, Height AGL, Mechanical Beam Tilt, Azimuth of
Mechanical Beam Tilt, Polarization, Max Simultaneous Transmitters

92. Each sector is to be assigned a number beginning with the sector
    whose main lobe azimuth is pointing due north or the closest to due
    north, proceeding in a clockwise direction from true north,
    numbering each sector in succession.

93. The receiving antenna pattern used in each sector is defined in the
    Antenna Pattern Data section, and the association of each sector
    with a specific antenna pattern is made here. This pattern shall be
    used in the calculation of potential interference to a hub from
    surrounding stations.

94. The geographic definition of each sector is found in the Sector
    Geographic Definitions section.

95. Any mechanical beam tilt and the azimuth of any mechanical beam tilt
    for each hub receiving antenna are specified in this section.
    Tilting the antenna downward is defined using a positive number. The
    Azimuth of Mechanical Beam Tilt shall specify the direction having
    the greatest downward depression.

96. The polarization of each sector is defined as horizontal (H),
    vertical (V), or both (B).The maximum number of transmitters that
    can operate simultaneously on the channel or on each sub-channel
    within each sector is specified in this section. The number
    specified shall apply to each sub-channel with power proportioned on
    a power spectral density basis.

**5. Grid Point Definitions**

Section Title: "Grid Points"

Header: \# of grid points (MMMM)

> Entries: Point 0001: Latitude, Longitude, Elevation, Region \# in
> which Located, Bearing to Hub, Polarization (H, V, or B), Number of
> associated Class(es) of Station(s), Class Designators
>
> Point 0002: Latitude, Longitude, Elevation, Region \# in which
> Located, Bearing to Hub, Polarization (H, V, or B), Number of
> associated Class(es) of Station(s), Class Designators
>
> **:**
>
> **:**
>
> Point MMMM: Latitude, Longitude, Elevation, Region \# in which
> Located, Bearing to Hub, Polarization (H, V, or B), Number of
> associated Class(es) of Station(s), Class Designators

97. The header specifies the total number of grid points (MMMM) defined
    in the Grid Point Definition Table.

98. The location of each grid point is defined by latitude and
    longitude. The bearing from the grid point to the hub is specified.
    The region in which the grid point is located is indicated using the
    region number assigned in the sections above giving geographic
    boundary definitions. Grid points not located in specifically
    defined regions shall be indicated as being in Region 00, which
    describes the remainder of the RSA. Grid points that are inactive
    because of the impossibility of installing response stations at
    their locations shall be shown as belonging to Region "\--"
    (16h,16h). Inactive grid points shall have the associated
    Polarization, Number of Classes, and Class Designator value
    positions filled with the space character (20h) as a place holder.

99. Polarization for each grid point must be specified as horizontal
    (H), vertical (V), or both (B). In areas where sectors having
    opposite polarizations overlap, it may be desirable to have the
    flexibility to utilize both polarizations. If so, grid points in
    these overlapping areas must be specified as B, both polarizations.

100. Each active grid point must be assigned at least one class of
     station. Assignment of multiple classes to a single grid point is
     also permitted.

6\. **Sector Geographic Definitions**

Section Title: "Sector Definitions"

Header: \# of sectors (SS), Bearings or Coordinates (B)

Entries: "Sector 01," Start Bearing, Stop Bearing

(Bearings) "Sector 02," Start Bearing, Stop Bearing

**:**

"Sector SS," Start Bearing, Stop Bearing

**OR**

Table Header: \# of sectors (SS), Bearings or Coordinates (C)

Entries: Sector 01 Entry Title, \# of Coordinates in Sector 01 (AAA)\
Sector 01Latitude (001), Sector 01 Longitude (001)\
Sector 01 Latitude (002), Sector 01 Longitude (002)\
Sector 01 Latitude (003), Sector 01 Longitude (003)\
**:**\
Sector 01 Latitude (AAA), Sector 01 Longitude (AAA)\
Sector 02 Entry Title, \# of Coordinates in Sector 02 (BBB)\
Sector 02 Latitude (001), Sector 02 Longitude (001)\
Sector 02 Latitude (002), Sector 02 Longitude (002)\
Sector 02 Latitude (003), Sector 02 Longitude (003)\
**:\
**Sector 02 Latitude (BBB), Sector 02 Longitude (BBB)\
Sector 03 Entry Title, \# of Coordinates in Sector 03 (CCC)\
Sector 03 Latitude (001), Sector 03 Longitude (001)\
Sector 03 Latitude (002), Sector 03 Longitude (002)\
Sector 03 Latitude (003), Sector 03 Longitude (003)\
**:\
**Sector 03 Latitude (CCC), Sector 03 Longitude (CCC)\
**:\
** **:\
**Sector SS Entry Title, \# of Coordinates in Sector SS (ZZZ)\
Sector SS Latitude (001), Sector SS Longitude (001)\
Sector SS Latitude (002), Sector SS Longitude (002)\
Sector SS Latitude (003), Sector SS Longitude (003)\
**:\
**Sector SS Latitude (ZZZ), Sector SS Longitude (ZZZ)

101. Sector geographic boundaries can be described in either of two
     ways: (1) as straight lines radiating out from the hub location at
     the specified bearings until they cross the outer boundary of the
     RSA, or (2) as sets of coordinates between which straight boundary
     lines exist that describe closed geographic areas. In either case,
     sectors may overlap, and, when they do, grid points in the overlap
     areas must be analyzed as though they were included exclusively
     within each sector. When sets of coordinates are used, the last
     coordinate pair shall be assumed to connect to the first such pair.

102. The data for the sector boundary descriptions lists pairs of
     latitude and longitude coordinates in sequence, with each group of
     data following an entry header. The entry header includes a title
     that numbers the area to which its data applies and a value
     indicating the number of entries in the list for its area.

**7. Sector Frequency Plan**

####### Section Title: "Frequency Plan"

> Header: \# of sectors (SS)
>
> Entries: "Sector 1," \# of Response Bands (R1)\
> Channel Designator 1, Lower Frequency, Upper Frequency\
> Channel Designator 2, Lower Frequency, Upper Frequency\
> :\
> Channel Designator R1, Lower Frequency, Upper Frequency\
> "Sector 2," \# of Response Bands (R2)\
> Channel Designator 1, Lower Frequency, Upper Frequency\
> Channel Designator 2, Lower Frequency, Upper Frequency\
> :\
> Channel Designator R2, Lower Frequency, Upper Frequency\
> :\
> :\
> "Sector SS," \# of Response Bands (RSS)\
> Channel Designator 1, Lower Frequency, Upper Frequency\
> Channel Designator 2, Lower Frequency, Upper Frequency\
> :\
> Channel Designator RSS, Lower Frequency, Upper Frequency

103. The header specifies the number of sectors for which frequency
     plans are included. The number of sectors must match the number of
     sectors listed previously in the headers of the sections with the
     titles "Sectorization" and "Sector Definitions." Sector numbering
     matches that used for defining the sectorization and sector
     geographic boundaries in the earlier sections.

104. The entry for each sector begins with a line listing the sector
     number and the number of response bands defined within that sector.
     Response bands defined are the frequency ranges to be used for
     communication from response stations to the response station hub;
     they do not represent the actual subchannelization used, which can
     vary from time-to-time. The limits of one response band are listed
     on a single line. They are preceded on that line by the channel
     designator of the 6 MHz channel from which they are drawn (e.g.,
     A3, F2, H1, M2A). There can be multiple response bands within a
     single 6 MHz channel, in which case the channel designator will
     appear in the list more than once. The entire 6 MHz channel also
     can be used, in which case its limits will be shown. Frequency
     bands are listed in ascending order.

105. Sector data proceeds from Sector 1 through the last sector (Sector
     SS) with no line spaces between the data from adjacent sectors.

**8. Response Station Class Data**

> Section Title: "Class Info"
>
> Header: \# of classes (CL)
>
> Entries: "Class 1," Worst Case Ant Pattern #, Max Height, Max Power,
> Number of Regions in Which Used, Region(s) in Which Used, Maximum
> Simultaneous Number within Each Region
>
> "Class 2," Worst Case Ant Pattern #, Max Height, Max Power, Number of
> Regions in Which Used, Region(s) in Which Used, Maximum Simultaneous
> Number within Each Region
>
> **:**
>
> **:**
>
> **"**Class CL," Worst Case Ant Pattern #, Max Height, Max Power,
> Number of Regions in Which Used, Region(s) in Which Used, Maximum
> Simultaneous Number within Each Region

106. Classes are defined by the combination of the worst case antenna
     pattern, the maximum height above ground level (AGL) at which the
     antennas may be mounted, and the maximum power (EIRP) they may
     emit.

107. Associated with each class description is one or more pairs of
     values indicating the region numbers in which the class is used and
     the maximum number of transmitters that may transmit simultaneously
     on the channel or on each sub-channel within each region. One pair
     is present for each region in which the particular class is used.
     The regions shall be listed in ascending numerical order. The
     maximum number of simultaneous transmitters specified shall apply
     to each sub-channel with power proportioned on a power spectral
     density basis.

**9. Antenna Pattern Data (Hub Receive and Worst Case Response Station
Transmit)**

Section Title: "Antenna Patterns"

Header: \# hub antenna patterns (HP), \# of worst case response station
transmit antenna patterns (RP)

> Entries: Hub 01 Entry Title, \# of Value Sets\
> Degrees of Azimuth, Plane Polarized dB, & Cross Polarized dB Headings\
> 000 Degrees, Plane dB, Cross dB\
> 001 Degrees, Plane dB, Cross dB\
> 002 Degrees, Plane dB, Cross dB\
> 003 Degrees, Plane dB, Cross dB
>
> **:**
>
> **:**
>
> 356 Degrees, Plane dB, Cross dB\
> 357 Degrees, Plane dB, Cross dB\
> 358 Degrees, Plane dB, Cross dB\
> 359 Degrees, Plane dB, Cross dB
>
> Degrees of Elevation, Plane Polarized dB, & Cross Polarized dB
> Headings\
> -90 Degrees, Plane dB, Cross dB\
> -89 Degrees, Plane dB, Cross dB\
> -88 Degrees, Plane dB, Cross dB\
> -87 Degrees, Plane dB, Cross dB
>
> :
>
> -01 Degrees, Plane dB, Cross dB\
> 000 Degrees, Plane dB, Cross dB\
> +01 Degrees, Plane dB, Cross dB
>
> **:**
>
> +87 Degrees, Plane dB, Cross dB\
> +88 Degrees, Plane dB, Cross dB\
> +89 Degrees, Plane dB, Cross dB\
> +90 Degrees, Plane dB, Cross dB
>
> Hub 02 Entry Title, \# of Value Sets\
> Degrees of Azimuth, Plane Polarized dB, & Cross Polarized dB Headings\
> 000 Degrees, Plane dB, Cross dB\
> 001 Degrees, Plane dB, Cross dB\
> 002 Degrees, Plane dB, Cross dB\
> 003 Degrees, Plane dB, Cross dB
>
> **:**
>
> :
>
> 356 Degrees, Plane dB, Cross dB\
> 357 Degrees, Plane dB, Cross dB\
> 358 Degrees, Plane dB, Cross dB\
> 359 Degrees, Plane dB, Cross dB
>
> Degrees of Elevation, Plane Polarized dB, & Cross Polarized dB
> Headings\
> -90 Degrees, Plane dB, Cross dB\
> -89 Degrees, Plane dB, Cross dB\
> -88 Degrees, Plane dB, Cross dB\
> -87 Degrees, Plane dB, Cross dB
>
> **:**
>
> -01 Degrees, Plane dB, Cross dB\
> 000 Degrees, Plane dB, Cross dB\
> +01 Degrees, Plane dB, Cross dB
>
> **:**
>
> +87 Degrees, Plane dB, Cross dB\
> +88 Degrees, Plane dB, Cross dB\
> +89 Degrees, Plane dB, Cross dB\
> +90 Degrees, Plane dB, Cross dB
>
> **:**
>
> **:**
>
> **:**
>
> Hub HP Entry Title, \# of Value Sets\
> Degrees of Azimuth, Plane Polarized dB, & Cross Polarized dB Headings\
> 000 Degrees, Plane dB, Cross dB\
> 001 Degrees, Plane dB, Cross dB\
> 002 Degrees, Plane dB, Cross dB\
> 003 Degrees, Plane dB, Cross dB
>
> **:**
>
> **:**
>
> 356 Degrees, Plane dB, Cross dB\
> 357 Degrees, Plane dB, Cross dB\
> 358 Degrees, Plane dB, Cross dB\
> 359 Degrees, Plane dB, Cross dB
>
> Degrees of Elevation, Plane Polarized dB, & Cross Polarized dB
> Headings\
> -90 Degrees, Plane dB, Cross dB\
> -89 Degrees, Plane dB, Cross dB\
> -88 Degrees, Plane dB, Cross dB\
> -87 Degrees, Plane dB, Cross dB
>
> **:**
>
> -01 Degrees, Plane dB, Cross dB\
> 000 Degrees, Plane dB, Cross dB\
> +01 Degrees, Plane dB, Cross dB
>
> **:**
>
> +87 Degrees, Plane dB, Cross dB\
> +88 Degrees, Plane dB, Cross dB\
> +89 Degrees, Plane dB, Cross dB\
> +90 Degrees, Plane dB, Cross dB
>
> Response 01 Entry Title\
> Degrees of Azimuth, Plane Polarized dB, & Cross Polarized dB Headings\
> 000 Degrees, Plane dB, Cross dB\
> 001 Degrees, Plane dB, Cross dB\
> 002 Degrees, Plane dB, Cross dB\
> 003 Degrees, Plane dB, Cross dB
>
> **:**
>
> **:**
>
> 356 Degrees, Plane dB, Cross dB\
> 357 Degrees, Plane dB, Cross dB\
> 358 Degrees, Plane dB, Cross dB\
> 359 Degrees, Plane dB, Cross dB
>
> Response 02 Entry Title\
> Degrees of Azimuth, Plane Polarized dB, & Cross Polarized dB Headings\
> 000 Degrees, Plane dB, Cross dB\
> 001 Degrees, Plane dB, Cross dB\
> 002 Degrees, Plane dB, Cross dB\
> 003 Degrees, Plane dB, Cross dB
>
> **:**
>
> **:**
>
> 356 Degrees, Plane dB, Cross dB\
> 357 Degrees, Plane dB, Cross dB\
> 358 Degrees, Plane dB, Cross dB\
> 359 Degrees, Plane dB, Cross dB
>
> **:**
>
> **:**
>
> **:**
>
> Response RP Entry Title\
> Degrees of Azimuth, Plane Polarized dB, & Cross Polarized dB Headings\
> 000 Degrees, Plane dB, Cross dB\
> 001 Degrees, Plane dB, Cross dB\
> 002 Degrees, Plane dB, Cross dB\
> 003 Degrees, Plane dB, Cross dB
>
> **:**
>
> **:**
>
> 356 Degrees, Plane dB, Cross dB\
> 357 Degrees, Plane dB, Cross dB\
> 358 Degrees, Plane dB, Cross dB\
> 359 Degrees, Plane dB, Cross dB

108. The hub receiving antenna and response station transmitting antenna
     azimuth patterns shall be defined in 1 degree increments beginning
     with 0 degrees and ending at 359 degrees. Hub receiving antenna
     elevation patterns shall be defined in 1 degree increments
     beginning at --90 degrees for the zenith, continuing through 0
     degrees at the reference horizontal plane, and ending at +90
     degrees for the nadir. All entries shall be in dB relative to the
     peak response, which shall be normalized to a value of 0 dB. . The
     peak response in the azimuth pattern shall be given at 0 degrees if
     there is only one peak, or the peaks shall be symmetrically placed
     around 0 degrees if there is more than one peak. The elevation
     pattern shall be given in the direction of the azimuth plane peak
     response, and the peak elevation response shall be shown at the
     depression angle below the reference horizontal plane at which it
     occurs, i.e. electrical beam tilt shall be built into the elevation
     pattern. Any rotations of the antenna pattern, either in azimuth or
     through mechanical beam tilt, are given in other sections.

109. Full azimuth data shall be supplied for both hub and response
     station worst-case antenna patterns. Elevation data is required
     only for hub antennas. In cases where hub antenna elevation data is
     known only over a limited range, just the known points should be
     entered. For example, if elevation data is known from --10 degrees
     to +40 degrees of elevation only, such data should be entered, even
     though incomplete. At a minimum, data shall be supplied for
     elevation angles every degree from --10 degrees to + 30 degrees.
     Where mechanical beam tilt is used, sufficient data shall be
     supplied to assure pattern inclusion to at least 5 degrees above
     the horizon (i.e., -5 degrees relative to the horizontal plane at
     the hub antenna location). Only those angles for which data is
     present should appear in the list, and the total number of value
     sets for each hub antenna pattern should be set to account for just
     those entries present. Headings shall not be counted in arriving at
     the total number. Where needed to properly model an antenna for
     which all values of the elevation pattern are not given, values not
     given shall be interpolated linearly in decibels between points for
     which data is given, using the sum (in decibels) of the azimuth and
     elevation patterns to arrive at the values between which
     interpolation shall be carried out.

110. When response stations operate with EIRP no greater than --6 dBW
     per 6 MHz channel ( or the bandwidth-adjusted equivalent on a power
     spectral density basis), they are permitted to use non-directional
     antennas. Such stations shall be treated as using isotropic
     radiators, which shall be indicated by use of the value --1 for the
     worst-case antenna pattern number in the section on "Class Info."
     No specification of the azimuth pattern of such an antenna is
     required in the section on "Antenna Patterns."

## Example File & Template

111. In the example file and template below, formatting elements and
     descriptive terms to be included in the submitted file exactly as
     shown are in plain text. Those items to be replaced by real data
     and shown here as placeholders for purposes of example are shown in
     *italicized text and CAPITAL LETTERS*.

\[General Info\]

File *FILE NUMBER*

Licensee **OR** Applicant *LICENSEE/APPLICANT NAME*

Hub Lat *DDMMSSS*, Hub Lon *DDDMMSSS*

Hub City *CITY, ST*

Elevation *AMSL METERS*

Call *CALL SIGN*

Stn City *CITY, ST*

\[Circular Geographic Areas\]

RSA *0/1*, Regions *00/RR*

00,*DDMMSSS,DDDMMSSS,KM.KM*

01,*DDMMSSS,DDDMMSSS,KM.KM*

02,*DDMMSSS,DDDMMSSS,KM.KM*

:: :::::: ::::::: ::::::

:: :::::: ::::::: ::::::

RR,*DDMMSSS,DDDMMSSS,KM.KM*

\[Non-Circular Areas\]

RSA *0/1*, Regions *00/NN*

RSA,*XXX\
DDMMSSS,DDDMMSSS*

######### DDMMSSS,DDDMMSSS

*DDMMSSS,DDDMMSSS*

::::::: ::::::::

*DDMMSSS,DDDMMSSS* \[Pair \# XXX\]

Region *RR+1,AAA*

*DDMMSSS,DDDMMSSS*

*DDMMSSS,DDDMMSSS*

*DDMMSSS,DDDMMSSS*

::::::: ::::::::

*DDMMSSS,DDDMMSSS* \[Pair \# AAA\]

Region *RR+2,BBB*

*DDMMSSS,DDDMMSSS*

*DDMMSSS,DDDMMSSS*

*DDMMSSS,DDDMMSSS*

::::::: ::::::::

*DDMMSSS,DDDMMSSS* \[Pair \# BBB\]

::::::: ::::::::

::::::: ::::::::

Region *RR+NN,ZZZ*

*DDMMSSS,DDDMMSSS*

*DDMMSSS,DDDMMSSS*

*DDMMSSS,DDDMMSSS*

::::::: ::::::::

*DDMMSSS,DDDMMSSS* \[Pair \# ZZZ\]

\[Sectorization\]

Sectors *SS*

Sector,HubPat,Gain,Az,AGL,MTilt,MTiltAz,Pol,Max#Trans

01,*HP,dB.dB,DDD.D,MMMM,DD.D,DDD.D,H/V/B,TTTT*

02,*HP,dB.dB,DDD.D,MMMM,DD.D,DDD.D,H/V/B,TTTT*

03,*HP,dB.dB,DDD.D,MMMM,DD.D,DDD.D,H/V/B,TTTT*

:: :: :: :: ::: : :::: :: : ::: : : : : ::::

:: :: :: :: ::: : :::: :: : ::: : : : : ::::

SS,*HP,dB.dB,DDD.D,MMMM,DD.D,DDD.D,H/V/B,TTTT*

\[Grid Points\]

Points MMMM

Pnt,Lat,Lon,Elev,Regn,Bearing,Pol,#Classes,ClassDesignators\...

0001,*DDMMSSS,DDDMMSSS,MMMM,R#,DDD.DD,H/V/B,###,CC1,CC2,CC3,\...CC###*

0002,*DDMMSSS,DDDMMSSS,MMMM,R#,DDD.DD,H/V/B,###,CC1,CC2,CC3,\...CC###*

0003,*DDMMSSS,DDDMMSSS,MMMM,R#,DDD.DD,H/V/B,###,CC1,CC2,CC3,\...CC###*

:::: :::::: ::::::: :: :: :::: : : : ::: ::: ::: ::: :::

:::: :::::: ::::::: :: :: :::: : : : ::: ::: ::: ::: :::

MMMM,*DDMMSSS,DDDMMSSS,MMMM,R#,DDD.DD,H/V/B,###,CC1,CC2,CC3,\...CC###*

\[Sector Definitions\]

Sectors *SS*, Type *B*

01,DD.DD,DD.DD

02,DD.DD,DD.DD

03,DD.DD,DD.DD

:: :: :: :: ::

:: :: :: :: ::

SS,DD.DD,DD.DD

**OR**

Sectors *SS*, Type *C*

Sector 01, Points *AAA*

*DDMMSSS,DDDMMSSS*

*DDMMSSS,DDDMMSSS*

*DDMMSSS,DDDMMSSS*

::::::: ::::::::

*DDMMSSS,DDDMMSSS* \[Pair \# AAA\]

Sector 02, Points *BBB*

*DDMMSSS,DDDMMSSS*

*DDMMSSS,DDDMMSSS*

*DDMMSSS,DDDMMSSS*

::::::: ::::::::

*DDMMSSS,DDDMMSSS* \[Pair \# BBB\]

Sector 03, Points *CCC*

*DDMMSSS,DDDMMSSS*

*DDMMSSS,DDDMMSSS*

*DDMMSSS,DDDMMSSS*

::::::: ::::::::

*DDMMSSS,DDDMMSSS* \[Pair \# CCC\]

::::::: ::::::::

::::::: ::::::::

Sector *SS*, Points *ZZZ*

*DDMMSSS,DDDMMSSS*

*DDMMSSS,DDDMMSSS*

*DDMMSSS,DDDMMSSS*

::::::: ::::::::

*DDMMSSS,DDDMMSSS* \[Pair \# ZZZ\]

\[Frequency Plan\]

Sectors *SS*

Sector 01, Response Bands *R1*

*D1,FFFF.FFF,FFFF.FFF*

*D2,FFFF.FFF,FFFF.FFF*

*D3,FFFF.FFF,FFFF.FFF*

:: :::: ::: :::: :::

*R1,FFFF.FFF,FFFF.FFF*

Sector 02, Response Bands *R2*

*D1,FFFF.FFF,FFFF.FFF*

*D2,FFFF.FFF,FFFF.FFF*

*D3,FFFF.FFF,FFFF.FFF*

:: :::: ::: :::: :::

*R2,FFFF.FFF,FFFF.FFF*

:: :::: ::: :::: :::

:: :::: ::: :::: :::

Sector *SS*, Response Bands *RS*

*D1,FFFF.FFF,FFFF.FFF*

*D2,FFFF.FFF,FFFF.FFF*

*D3,FFFF.FFF,FFFF.FFF*

:: :::: ::: :::: :::

*RS,FFFF.FFF,FFFF.FFF*

\[Class Info\]

Classes *CL*

Class,Pattern,AGL,MaxEIRP,#Reg,Reg,Max#Tx

01,*PAT,MMM,dB.dB,##,R1,##R1,R2,##R2,\...RG,##RG*

02,*PAT,MMM,dB.dB,##,R1,##R1,R2,##R2,\...RG,##RG*

03,*PAT,MMM,dB.dB,##,R1,##R1,R2,##R2,\...RG,##RG*

:: ::: ::: :: :: :: :: :::: :: :::: :: ::::

:: ::: ::: :: :: :: :: :::: :: :::: :: ::::

CL,*PAT,MMM,dB.dB,##,R1,##R1,R2,##R2,\...RG,##RG*

\[Antenna Patterns\]

Hub *HP*, Response *RP*

Hub 01,*\###*Values

DegAz,Plane dB,Cross dB

000,*dB.dB*,*dB.dB*

001,*dB.dB*,*dB.dB*

002,*dB.dB*,*dB.dB*

003,*dB.dB*,*dB.dB*

::: :: :: :: ::

::: :: :: :: ::

357,*dB.dB*,*dB.dB*

358,*dB.dB*,*dB.dB*

359,*dB.dB*,*dB.dB*

DegEl,Plane dB,Cross dB

-90,*dB.dB*,*dB.dB*

-89,*dB.dB*,*dB.dB*

-88,*dB.dB*,*dB.dB*

::: :: :: :: ::

-01,*dB.dB*,*dB.dB*

000,*dB.dB*,*dB.dB*

+01,*dB.dB*,*dB.dB*

::: :: :: :: ::

+88,*dB.dB*,*dB.dB*

+89,*dB.dB*,*dB.dB*

+90,*dB.dB*,*dB.dB*

######## Hub 02,*\###*Values

DegAz,Plane dB,Cross dB

000,*dB.dB*,*dB.dB*

001,*dB.dB*,*dB.dB*

002,*dB.dB*,*dB.dB*

003,*dB.dB*,*dB.dB*

::: :: :: :: ::

::: :: :: :: ::

357,*dB.dB*,*dB.dB*

358,*dB.dB*,*dB.dB*

359,*dB.dB*,*dB.dB*

DegEl,Plane dB,Cross dB

-90,*dB.dB*,*dB.dB*

-89,*dB.dB*,*dB.dB*

-88,*dB.dB*,*dB.dB*

::: :: :: :: ::

-01,*dB.dB*,*dB.dB*

000,*dB.dB*,*dB.dB*

+01,*dB.dB*,*dB.dB*

::: :: :: :: ::

+88,*dB.dB*,*dB.dB*

+89,*dB.dB*,*dB.dB*

+90,*dB.dB*,*dB.dB*

::: :: :: :: ::

::: :: :: :: ::

Hub HP,*\###*Values

DegAz,Plane dB,Cross dB

000,*dB.dB*,*dB.dB*

001,*dB.dB*,*dB.dB*

002,*dB.dB*,*dB.dB*

003,*dB.dB*,*dB.dB*

::: :: :: :: ::

::: :: :: :: ::

357,*dB.dB*,*dB.dB*

358,*dB.dB*,*dB.dB*

359,*dB.dB*,*dB.dB*

DegEl,Plane dB,Cross dB

-90,*dB.dB*,*dB.dB*

-89,*dB.dB*,*dB.dB*

-88,*dB.dB*,*dB.dB*

::: :: :: :: ::

-01,*dB.dB*,*dB.dB*

000,*dB.dB*,*dB.dB*

+01,*dB.dB*,*dB.dB*

::: :: :: :: ::

+88,*dB.dB*,*dB.dB*

+89,*dB.dB*,*dB.dB*

+90,*dB.dB*,*dB.dB*

######## Response 01

DegAz,Plane dB,Cross dB

000,*dB.dB*,*dB.dB*

001,*dB.dB*,*dB.dB*

002,*dB.dB*,*dB.dB*

003,*dB.dB*,*dB.dB*

::: :: :: :: ::

::: :: :: :: ::

357,*dB.dB*,*dB.dB*

358,*dB.dB*,*dB.dB*

359,*dB.dB*,*dB.dB*

######## Response 02

DegAz,Plane dB,Cross dB

000,*dB.dB*,*dB.dB*

001,*dB.dB*,*dB.dB*

002,*dB.dB*,*dB.dB*

003,*dB.dB*,*dB.dB*

::: :: :: :: ::

::: :: :: :: ::

357,*dB.dB*,*dB.dB*

358,*dB.dB*,*dB.dB*

359,*dB.dB*,*dB.dB*

::: :: :: :: ::

::: :: :: :: ::

######## Response RP

DegAz,Plane dB,Cross dB

000,*dB.dB*,*dB.dB*

001,*dB.dB*,*dB.dB*

002,*dB.dB*,*dB.dB*

003,*dB.dB*,*dB.dB*

::: :: :: :: ::

::: :: :: :: ::

357,*dB.dB*,*dB.dB*

358,*dB.dB*,*dB.dB*

359,*dB.dB*,*dB.dB*

[^1]: Conversion from NAD-27 to NAD-83 shall be done using the algorithm
    incorporated in the NADCON software, version 2.1 or later, as
    specified in the Federal Register for August 10, 1990, Volume 55,
    Number 155, page 32681, and available formatted for IBM
    PC-compatible computers from the National Oceanic and Atmospheric
    Administration at: NOAA, NGS, N/NGS12, 1315 East West Highway,
    Station 9202, Silver Spring, MD 20910-3282, phone number (800)
    638-8972.

[^2]: When dissimilar bandwidths are used by the desired and undesired
    stations, methods for adjusting the required D/U ratios are provided
    respectively in: 21.902(b)(7)(ii) for MDS analysis of co-channel
    stations, 21.902(b)(7)(iii) for MDS analysis of adjacent channel
    stations, 74.903(a)(6)(ii) for ITFS analysis of co-channel stations
    and 74.903(a)(6)(iii) for ITFS analysis of adjacent channel
    stations. Those rules are cross-referenced in 21.909(d)(3)(iv) and
    (v) and 74.939(d)(3)(iv) and (v), which discuss compliance by
    applicants for response station hubs with the 45 dB and 0 dB D/U
    requirements.

[^3]: "Transmission Loss Prediction for Tropospheric Communication
    Circuits," Technical Note 101, NTIS Access Number AD 687-820,
    National Technical Information Service, US Department of Commerce,
    Springfield, VA.

[^4]: An example of such a software implementation is the Free Space +
    RMD™ method included in some products of EDX Engineering, Inc.

[^5]: J. Epstein and D.W. Peterson. "An experimental study of wave
    propagation at 850 Mc.," Proc. IRE, vol. 41, no. 5, pp. 595-611,
    May, 1953.

[^6]: ISO/IEC 9293: 1994, Information Technology --- Volume and File
    Structure of Flexible Disk Cartridges for Information Interchange

[^7]: ISO/IEC 9529-1:1987, Information Processing Systems--- Data
    Interchange on 90 mm (3.5 in) Flexible Disk Cartridges Using
    Modified Frequency Modulation Recording at 15916 ftprad on 80 Tracks
    on Each Side --- Part 1: Dimensional, Physical and Magnetic
    Characteristics.

[^8]: ISO/IEC 9529-2:1987, Information Processing Systems --- Data
    Interchange on 90 mm (3.5 in) Flexible Disk Cartridges Using
    Modified Frequency Modulation Recording at 15916 ftprad on 80 Tracks
    on Each Side --- Part 2: Track Format

[^9]: The cited ISO/IEC standards describe disks having a formatted
    capacity of 1.44 Mbytes. It is intended to allow the use of disks of
    other capacities (such as 720 kBytes) based upon the same techniques
    as and compatible with the disks described in the specified
    standards.

[^10]: ISO 9660: 1988, Information Processing --- Volume and File
    Structure of CD-ROM for Information Interchange

[^11]: ANSI X3.4-1986 (R1992), Coded Character Set --- 7-Bit American
    National Standard Code for Information Interchange

[^12]: All coordinates shall be based on use of the U.S. Geological
    Survey (USGS) 3-second database and shall be referenced to the 1983
    North American Datum (NAD-83).