Users Manual Part 1

Figure 65: Holes in Top Lid for Rx Cables
Holes in Top lid for connecting
Filters in Prime Cabinet to RX
Splitters in Expansion Cabinet
4.8
GPS Connections
The MTS Site Controller (SC) has an integrated GPS module and an option for a remote GPS module.
The selection is done by configuring MTS using the BTS Service Software (TESS). The integrated
GPS module can track both GPS and GLONASS satellites. At least 1 GPS satellite needs to be traced
to provide time reference for the SC. Remote GPS module currently supports GPS and Beidou GNSS.
GLONASS on the remote GPS module will be supported in the future.
The main purpose of the GPS module is to allow accurate absolute timing of less than ½ of a symbol
between adjacent base stations and to supply UTC (Universal Time Coordinate). DIMETRA does not
need the functionality of measuring the cable delay at start-up. The Site Controller supports connection
to a remote GPS antenna that is 600 m away or less. No manual configuration is required.
The antenna/receiver must have a sufficiently clear view of the sky (10º above the horizon in all
directions without any obstructions) to be able to locate and track at least four satellites during initial
power-up. The four satellites are used to establish a three-dimensional fix (latitude, longitude, and
altitude) for the site called 3D fix mode. This process can take up to 30 minutes, but typically is
completed in less than 5 minutes.
Once the position of the site has been established, the corresponding data is stored in memory and
normal operation resumes.
4.8.1
GPS Site Reference Operation Modes
The ETSI standard allows two modes of operation of adjacent cells: Synchronized and Non-
Synchronized relative to the serving cell. The MTS uses GPS to synchronize to the same time
reference. Both the serving MTS and the adjacent cell need to be synchronized to GPS for an adjacent
cell to be indicated for synchronization.
MTS can be configured through the BTS Service Software for four different operating configurations,
which control the synchronization mode:
• Automatic Synchronized Configuration (ASC)
This configuration is used to specify that the MTS should operate in synchronized mode relative to
GPS. However, if the GPS reference is lost, the MTS continues to operate in synchronized mode for
a configurable period (free run time – no upper limit). It should be noted that setting this value
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Chapter 4: Hardware Installation
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