Motorola PTP 400 Series - Manual (Page 164)

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13.4 Deployment Considerations
The majority of radio links can be successfully deployed with the PTP 400 Series Bridge. It
should only be necessary to use external antennas where the Link Budget Calculator
indicates marginal performance for a specific link – for example, when the link is heavily
obscured by dense woodland on an NLOS link or extremely long LOS links (>80km or > 50
miles) over water.
The external antennas can be either dual-polarization (as the integrated antenna) or two
single polarized antennas can be used in a spatially diverse configuration. It is expected that
the dual-polarization antennas would normally be used to simplify the installation process;
spatially diverse antennas may provide additional fade margin on very long LOS links where
there is evidence of correlation of the fading characteristics on Vertical and Horizontal
polarizations.
Dual polarization antennas (with a gain greater than the integrated antenna) are currently only
available in parabolic dish form.
13.5 Link Budget
An estimate of the link budget for a specific application can be obtained by using the Motorola
link estimation tools. For more information see the Motorola web site.
13.6 Regulatory Issues
In countries where FCC regulations are not relevant, installations should conform to any
applicable local regulations for the Equivalent Isotropic Radiated Power (EIRP).
Ensuring compliance becomes more complex when the Connectorized unit is used with
external antennas, which may be locally sourced. With higher gain external antennas fitted,
the Maximum Transmit power may need to be reduced for operation in specific countries.
See Table 7 in section 5.2 “Region Codes” for any EIRP restrictions that may apply in your
region.
13.6.1 Antenna Choice (5.8GHz FCC Regions Only)
The antennas which can be deployed with the Connectorized version of the PTP 400 Series
bridge are shown in Table 20.