Alvarion BreezeNET PRO.11 Series User Manual page 178

Appendix
Example:
Link Parameters:
Frequency: 2.4 Ghz
P = 4 dBm (2.5 mW)
out
Tx and Rx cable length (Ct and Cr) = 10 m. cable type RG214 (0.6 dB/meter)
Tx and Rx antenna gain (Gt and Gr) = 18 dBi
Distance between sites = 3 Km
Receiver sensitivity (Ps) = -84 dBm
Link Budget Calculation
EIRP = P
Pl = 32.4 + 20xLog(FMhz) + 20xLog(RKm) 110 dB
Si = EIRP - Pl + Gr - Cr = -82 dBm
In conclusion, the received signal power is above the sensitivity threshold, so the
link should work. The problem is that there is only a 2 dB difference between
received signal power and sensitivity. Normally, a higher margin is desirable due to
fluctuation in received power as a result of signal fading.
User's Guide
- Ct + Gt = 16 dBm
out
9-22 BreezeNET PRO.11 Series