User's Manual

PN 8700-10 Help Hot Line (U.S. only): 1-800-530-9960 8-19
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PRELIMINARY Estimating RF Coverage
8.2 Estimating RF Coverage
The maximum power per carrier (based on the number and type of RF carriers that
are being transmitted) and the minimum acceptable received power at the wireless
device (i.e., RSSI, the design goal) establish the RF link budget, and consequently the
maximum acceptable path loss between the antenna and the wireless device.
Figure 8-1 Determining Path Loss between the Antenna and the Wireless Device
(P + L
coax
+ G) – RSSI = PL (1)
The path loss (PL) is the loss in decibels (dB) between the antenna and the wireless
device. The distance, d, from the antenna corresponding to this path loss can be calcu-
lated using the path loss equations in Section 8.2.1 and in Section 8.2.2.
The following table lists the coaxial cable loss for XXX size cable. Enrique:
What diameter coax? (Adam)
Table 8-15 Coaxial Cable Losses
Length of
Cable
Loss at
800 MHz
(dB)
Loss at
1900 MHz
(dB)
0.9 m (3 ft) 0.4 0.6
1.8 m (6 ft) 0.9 1.4
3.0 m (10 ft) 1.5 2.4
RAU
P = power per
d
Antenna and Gain (G)
RSSI = power at the
wireless device
carrier from the RAU