User Manual

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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 — supplied by NextNet and manufactured by Trimble Navigation
Limited — is a smart antenna in a sealed, shielded, self-contained unit that houses
a GPS receiver, GPS antenna, and interface circuitry. A lightning protector is also
supplied.
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 supplied Trimble 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 and lightning protector do 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.
• You must install lightning protection equipment. It is recommended that the
lightning protector be installed at the smart antenna end of the time source
interface cable. You must then directly connect the protection ground wire to a
properly grounded equipment chassis or antenna mast.
• Ensure at least half of the sky is clearly visible to the unit.