User's Manual

5-44 Configuring, Installing, and Using Carrier Infrastructure
4 Reboot the base station. When the CPEs re-register with the base station, the base station
places them on the legacy VLAN.
Configuring the time signal used by base stations
Expedience base stations require a time synchronization signal in order to determine the
proper timing for time division duplexing (TDD).
Because most Expedience system deployments use multiple base stations, at multiple cell
sites, most service providers will configure their base stations to use the time synchronization
signal generated by the Expedience system’s global positioning system (GPS).
However, if your deployment includes only one base station or one cell site, you can disable
the use of an external GPS. Your base station will then use a time signal generated by the base
station itself or another base station in the cell for time synchronization.
The GPS supplied time signal is known as an external time signal, which is the default setting
of the base station when shipped from the factory.
The base station generated time signal is known as an internal time signal.
Configuring the GPS to supply the time signal
To use the GPS to supply the time signal to base stations:
1 Supply power to the entire system, as described in the section “Powering base stations” on
page 6-61 in this guide.
2 Connect the GPS to a base station, as described in the section “Connecting the GPS
equipment to a base station” on page 6-59 in this guide.
3 Connect all base stations in your cell to each other, in a daisy chain manner. For further
information, refer to the section “Connecting the GPS equipment to a base station” on
page 6-59 in this guide.
4 Configure the base station to use an external time synchronization signal:
set airlink timing external
5 Save changes in Flash memory by issuing the write command.
6 For changes to take effect, reboot or reset the base station’s power. To reboot, type the
following at the command prompt:
reboot
Configuring a base station to supply a time signal
There are two scenarios in which you might want to set up a base station to use internal time
synchronization.
The first is a single base station at a cell that is not part of a larger system with other sites.
This base station may be set to use internal time synchronization.
The second scenario is a multiple base station site that is not part of a larger system with other
sites. One of the base stations is set as a master base station. The master base station is set for
internal time synchronization. It generates the 1-pulse-per-second (pps) for itself, and also
outputs the 1 pps pulse for the other base stations. As such, you then set the other base
stations to use external time synchronization.
To use a base-station generated time signal: