Alvarion BreezeNET PRO.11 Series User Manual page 175

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
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
Isotropic Antenna
A hypothetical antenna having equal radiation intensity in all directions. Used as a
zero dB gain reference in directivity calculation (gain).
Antenna Gain
A measure of directivity. It is defined as the ratio of the radiation intensity in a
given direction to the radiation intensity that would be obtained if the power
accepted by the antenna was radiated equally in all directions (isotropically).
Antenna gain is expressed in dBi.
BreezeNET PRO.11
) + 20xLog(R )
Mhz Km
)
Km
9-19
Appendix
User's
Guide