Remote GPS Head Installation
DRAFT
SC
300 1X BTS Hardware Installation, ATP, and FRU Procedures
JAN 2002
3-16
Objective
The objective of this procedure is to show how to install the Remote
Global Positioning System (RGPS) head.
Required Tools and Materials
One RGPS Head (Motorola Part Number 0186012H03) is required to do
this procedure.
RGPS Mounting
Considerations
The RGPS Head requires specific mounting considerations in order to
properly observe the GPS satellites.
The mounting pipe for the RGPS head should be mounted vertically
with less than five degrees (5
) of tilt.
The RGPS head mounting hardware which comes with the RGPS
head should be used in all installations. This mounting hardware
properly isolates the painted metal base of the RGPS head from other
conductive surfaces. If the metal base comes in contact with another
conductive surface, the electrical surge resistance of the RGPS head
can be significantly reduced leading to RGPS head failure.
– If the supplier of the RGPS mounting hardware cannot be used, the
installer MUST make certain that the metal base of the RGPS head
does not make contact with any conductive surface.
Position the RGPS head to have an unobstructed view of the sky and
to minimize the chance of debris (leaves, dirt, etc.) accumulating on
the radome of the RGPS head.
The RGPS head must have a clear view of the sky, preferably to
within ten degrees (10
) of the horizon in all directions. The total
blockage of the sky (due to buildings, mountains, etc.) should be less
than 50%.
Place the RGPS head as far away from the BTS transmit antenna as
possible to avoid RF interference issues.
Place the RGPS head at least 15 m away from lightning rods, towers,
or structures that attract lightning. RGPS head damage is usually not
the result of a direct lightning strike, but of a lightning strike on a
nearby structure. Also, since a lightning rod is connected to an earth
ground, it can act as a shield and create a shadow that may block or
reduce the signal from a satellite.
After you power on the BTS, you can check the RGPS signal
strengths with the
GPS_STATUS
command on the MMI port.
– An optimal installation will have at least one satellite (SV) with an
RSSI value
≥
50, and at least four (4) satellites with RSSI values
≥
45.
– A minimal installation should have at least four (4) satellites with
RSSI values
≥
40.
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