Cambium PTP 450 series, Руководство пользователя

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PTP 450 User Guide Link planning
2-58
ptp-450 (July 2014)
Calculating Link Loss
The link loss is the total attenuation of the wireless signal between two point-to-multipoint units. The link loss
calculation is presented below:
Link Loss (dB) = Transmit power of the remote wireless unit (dBm) − Tx Cable loss (dB) − Received
power at the local unit (dBm) – Rx cable loss (dB) + Antenna gain at the remote unit (dBi) + Antenna gain at
the local unit (dBi)
Calculating Rx Signal Level
The determinants in Rx signal level are illustrated in Figure 12 .
Figure 12 Determinants in Rx signal level
Rx signal level is calculated as follows:
Rx signal level dB = Tx power − Tx cable loss + Tx antenna gain
− free space path loss + Rx antenna gain − Rx cable loss
This Rx signal level calculation presumes that a clear line of sight is established between the transmitter and
receiver and that no objects encroach in the Fresnel zone.