BPR-10 — Application Procedures and Rules for Digital Television (DTV) Undertakings (sf10176)

Appendix 8 – Planning Factors for DTV Reception

The planning factors shown below led to the values of field strength given in tables 1 and 2 of Section B. The field strength values are found by solving the equation:

\(Field (dB\mu V/m) = C/N - K_{d} - K_{a} - G + L + N_{t} + N_{s} \)

These planning factors are assumed to characterize the equipment, including antenna systems, used for home reception. They determine the minimum field strength for DTV reception as a function of frequency band and as a function of channel number in the UHF band.

Table 1 — Planning factors for DTV reception
Planning Factor Symbol Low VHF High VHF UHF
Geometric Mean Frequency (MHz) F 69 194 615
Dipole Factor (dBm-dBμV/m) Kd −111.8 −120.8 −130.8
Dipole Factor Adjustment Ka None None See Text
Thermal Noise (dBm) Nt −106.2 −106.2 −106.2
Antenna Gain (dBd) G 4 6 10
Downlead Line Loss (dB) L 1 2 4
System Noise Figure (dB) Ns 10 10 7
Required Carrier to Noise Ratio (dB) C/N 15 15 15

The adjustment, Ka = 20 log[615/(channel mid-frequency in MHz)], is added to Kd to account for the fact that the field strength requirements are greater for UHF channels above the geometric mean frequency of the UHF band and smaller for UHF channels below that frequency.