User Manual

5-56 Configuring, Installing, and Using Carrier Infrastructure
4 Make sure the coaxial line is properly grounded.
5 Properly seal the co-axial connections with weatherproof components, tape and wrap.
Connecting the GPS equipment to a base station
The GPS equipment provides a time synchronization signal to the base station. This signal is
needed to ascertain the proper timing for time division duplexing (TDD).
The equipment is a smart antenna in a sealed, shielded, self-contained unit that houses a GPS
receiver, GPS antenna, and interface circuitry.
When powered, the GPS provides accurate time, with a time pulse of one pulse per second,
synchronized to Universal Time, Coordinated (UTC) within 150 nanoseconds.
GPS equipment mounting tips
You must use the NextNet Wireless supplied GPS system to supply a time synchronization
signal to the base stations in a cell. You cannot use a GPS from another manufacturer.
The GPS does not ship with mounting accessories. You can obtain these accessories from
many suppliers around the world, especially distributors of marine products.
Follow these tips when mounting the GPS:
• Mount the GPS unit on a threaded pipe or pole.
• The GPS mounting socket accepts a 1.0000 x 14 straight thread. It is recommended that
the pole/pipe you use be 1.000 inch.
• Secure the pipe or pole to the building or other support structure.
• Ensure at least half of the sky is clearly visible to the unit.
• Expose the unit to the southern portion of the sky. GPS satellites move generally from the
southwest to the northeast.
Connecting the GPS unit to the base station
One GPS unit can support numerous base stations in the same cell.
Use the GPS-to-base station cable to attach the GPS unit to one of the base stations in the
cell.
To connect the cable to the GPS unit and to the base station (both of which have already
been installed and mounted):
1 Connect the cable’s molded, circular female connector to the GPS unit.
2 After connecting the cable to the GPS unit, run the cable to the base station. Plug the
cable’s other end into the base station’s GPS connector.
3 Secure the cable that you just ran to an appropriate support structure. Coil and tie any
excess cable.
4 The GPS unit receives its power from the base station. The base station supplies power to
the GPS device, which uses 18 volts DC at 150 milliamperes.