How does TAP™ incorporate frequency diversity in microwave link reliability predictions?

The TAP fixed facility database includes a field for frequency diversity. If frequency diversity is not employed, set the “Diversity Frequency” field to zero (0). If frequency diversity is used, enter the second frequency in MHz.

The improvement factor for frequency diversity is computed from the following equations, depending on the frequency of the system:

Ifd[ 2 GHz] = 1.0000 (df / f) 10F/10
Ifd[ 4 GHz] = 0.5000 (df / f) 10F/10
Ifd[ 6 GHz] = 0.2500 (df / f) 10F/10
Ifd[ 7-8 GHz] = 0.1250 (df / f) 10F/10
Ifd[11-12 GHz] = 0.0833 (df / f) 10F/10

where:

  • f is the frequency in GHz
  • df is the diversity spacing in GHz
  • F is the thermal or composite fade margin

The constant coefficient of the equation is interpolated linearly for intermediate frequencies. Frequencies above or below the specified ranges use the coefficients for the highest or lowest range, respectively.

If both spatial and frequency diversity are employed, the combined improvement factor is the product of the two values.