Shown in the figure is the Free Space Loss (FSL) calculation page provided by YDI.COM. As shown in the Figure, there are two (2) main parameters needed to calculate FSL, namely,
- Operating Frequency (in MHz)
- Distance Between Antennas (in Miles)
The output of the calculation is
- Free Space Loss (in dB)
The formula as shown clearly in the figure is
Free Space Loss (dB) = 20 Log10 (MHz) + 20 Log10 (Distance in Miles) + 36.6
We will normally see a Free Space Loss in the range of 100 dB for radio signal operating in 2.4GHz frequency traveling in one (1) km distance.