Multitech MultiConnect xDot Developer's Manual page 30

SPECIFICATIONS AND PIN INFORMATION
The following table provides example settings and the theoretical maximum range based on these settings.
Example
Frequency
TX Power
TX Antenna Gain
1
RX Sensitivity
RX Antenna Gain
2
Fade Margin
Distance
Distance
1
RX Sensitivity is set to a conservative -120dBm, but can vary from -117 to -137dBm.
2
Fade Margin is set at the worst case of 30dB. Fade margin is an allowance a system designer includes to account
for unknown variables. The higher the fade margin, the better the overall link quality will be. With a fade margin
set to zero, the link budget is still valid, but only in LOS conditions, which is not practical for most designs. The
amount of fade margin to include in a calculation depends on the environment in which you will deploy the
system. A fade margin of 12 dBm is good, but a better number would be 20 to 30 dBm.
30
18dB Transmit Power for
915 MHz Models
915
19
3
-120
3
30
8.14
13.08
Units Example 14dB Transmit Power for
868MHz Models
MHz 868
dBm 14
dB 3
dBm -120
dB 3
dB 30
Miles 5.41
Km 8.70
®
xDot Developer Guide for Japan