NextNav LLC 200-0013-02 用户手册
Document Name: MARS Box User Manual
Version No: 0.2
Company Name: NextNav, LLC.
Confidential
Page 9
10/24/2013
Page 9 of 9
3.2 Tune-up procedure not to exceed maximum TX power
A CSV file
(configuration file)
per transmitter are created by the NOC engineer based on the
installation parameters such as line lengths, antenna type etc.
The TX output power level setting is contained in the CSV file.
The output power is adjusted by the ‘attenuation’ setting. This value in the CSV file is
calculated by a formula to set the output power (not to exceed 4W EIRP). The variables used
in the calculation include PA Gain (G
The output power is adjusted by the ‘attenuation’ setting. This value in the CSV file is
calculated by a formula to set the output power (not to exceed 4W EIRP). The variables used
in the calculation include PA Gain (G
pa
)
, TX Antenna Gain (G
ant
)
, TX filter insertion loss
(IL
flt
)
, internal cable loss (IL
int
)
, external cable loss (IL
ext
)
, and transceiver output power
(P
TCVR
)
.
EIRP (W) = 10^((P
TCVR
-
IL
int
+
G
pa
-
IL
flt
-
IL
ext
+
G
ant
) / 10) / 1000
3.3 GPS Receive Antenna
GPS antenna should be installed such that it has clear view of sky. Ideally, you would keep the
antenna close to the ground away from obstruction
• Keep any horizontal blockage smaller than 10 degrees
• Obstruction Clearance guideline
– If it is 1 ft wide it should be at least 6 ft away
– If it is 10 ft wide, it should be at least 60 ft. away.
– If it is significantly less than 1 ft wide (like a guy wire, or a post) it should not cause any
measurable effect
antenna close to the ground away from obstruction
• Keep any horizontal blockage smaller than 10 degrees
• Obstruction Clearance guideline
– If it is 1 ft wide it should be at least 6 ft away
– If it is 10 ft wide, it should be at least 60 ft. away.
– If it is significantly less than 1 ft wide (like a guy wire, or a post) it should not cause any
measurable effect