User Manual

Chapter 3 - Operation and Administration of the Macro BTS NPU Configuration
4Motion 419 System Manual
The GPS clock generates a 1PPS signal and is connected to the 4Motion shelf via
the GPS SYNC IN connector on the front panel of the NPU. The GPS clock
requirements can be reached by an outdoor installed GPS unit when it is
synchronized to a minimum number of (user-configurable) satellites.
This section describes the commands to be used for:
 “Configuring the GPS Clocks” on page 419
 “Configuring General Configuration Parameters for the GPS” on page 422
 “Configuring the Date and Time” on page 424
 “Configuring the Daylight Saving Parameters” on page 425
 “Configuring the Position” on page 426
 “Configuring the Required Number of Satellites” on page 428
 “Displaying GPS Clocks Parameters” on page 429
 “Displaying GPS General Configuration Parameters” on page 430
 “Displaying the Date and Time Parameters” on page 431
 “Displaying the Daylight Saving Parameters” on page 431
 “Displaying the Position Parameters” on page 432
 “Displaying the Number of Satellite Parameters” on page 432
3.4.16.2.1 Configuring the GPS Clocks
The GPS clock parameters determines the source for the main clocks in the
system. To configure the GPS clock, you are required to enable/disable:
 External 1PPS: Determines the air-frame start time. Assuming that all systems
use the same air-frame size and DL/UL Ratio, then, when the 1PPS clock is
received from a GPS system, this mechanism ensures inter-site and intra-site
IMPORTANT
Implementation of GPS synchronization is based on the assumption that all sectors are operating with
the same frame size and with the same DL/UL ratio.