Alvarion BreezeNET DS.11 User Manual page 83

For example: If, due to attenuation, half the power is lost (P
attenuation in dB is -10 x Log (1/2) = 3
Path Loss
Loss of power of an RF signal traveling (propagating) through space. It is
expressed in dB. Path loss depends on:
The distance between transmitting and receiving antennas
Line of sight clearance between the receiving and transmitting antennas
Antenna height
Free Space Loss
Attenuation of the electromagnetic wave while propagating through space. This
attenuation is calculated using the following formula:
Free space loss = 32.4 + 20xLog(F
F is the RF frequency expressed in MHz.
R is the distance between the transmitting and receiving antennas.
At 2.4 GHz, this formula is: 100+20xLog(R
BreezeNET BU-DS.11/RB-DS.11
Appendix B. Radio Signal Propagation
dB
) + 20xLog(R )
MHz Km
)
Km
A-3
/P = 1/2),
out
in
User's Guide