Product Info

RGPS (R emote GPS) Head Chapter 12: RGPS Head R eplacement Procedure
RGPS (Remote GPS) Head
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RGPS Head Description
The optional RGPS head is remotely located from the UBS Macro BTS frame. The RGPS head
is typically mounted outside on a mast/pole. (See Figure 1 -18 RGPS Head Mounting Details
on page 1 - 50 .)
The RGPS head contains a GPS Receiver (GPSR) and built -in GPS RF antenna.
The RGPS head 12–pin Deutsch type MMP connector is cabled to the S SI RGPS connector . This
connection allows the S SI to supply DC power to the RGPS head. In addition, control/data
signals are exchanged between the UBS Macro BTS frame and RGPS head via this connection.
The RGPS head successfully tracks and acquires GPS satellites. The RGPS head detects GPS
RF signals and extracts a 1 Pulse P er Second (1PPS) timing signal. This 1PPS signal is applied
to the DMI controller via the S SI connector . The DMI controller contains an internal Medium
Stability Oscillator (MSO) that is synchronized to the 1PPS timing signal and locked to the GPS
time base. If satellite tracking is lost or if the RGPS head fails, the MSO can maintain system
timing for up to 8 hours.
If the UBS Macro BTS frame is equipped with an optional Quartz High Stability Oscillator
(QHSO) that is mounted to the rear of the S SI, the DMI controller selects the QHSO as the
backup synchronization source instead of the MSO . The QHSO can maintain system timing
for up to 24 hours.
Motorola RGPS Heads
Currently there are two Motorola RGPS heads that may be used with UBS Macro BTS equipment
(see Figure 1 -19 RGPS Head Equipment on page 1 - 51 ). These are as follows:
• A later version Motorola RGPS head is typically installed at a new UBS Macro BTS site.
• An earlier version Motorola RGPS head already installed at and existing Motorola equipped
BTS site that is being upgraded with UBS Macro BTS equipment.
The installed RGPS cabling supports operation of either version RGPS head. However , the later
version RGPS head requires that the cabling to the head be routed outside the RGPS mounting
mast/pole while the earlier version RGPS head requires that the cabling to the head be routed
through the RGPS mounting mast/pole.
12 -2 68P09283A64 -3
FOA SEP 2007