User Manual

5-57
5
So that the remaining base stations in the cell can receive a GPS signal, connect a base
station adjacent to the base station you just connected to the GPS unit.
Continue to use the daisy chain wiring scheme to connect the remaining base stations, until
all of the base stations within the cell are connected to each other.
On the last base station in the daisy chain, connect the load termination on the open GPS
connection.
Connecting to the backbone network
The base station connects to a TVS module. You then connect the TVS module to your
network. Typically, base stations connect to a level 2 switch at the cell site, using a 10BaseT
connection. The switch controls the base station data traffic to and from the backbone
network.
Connect the switch to the backhaul network using the appropriate cabling.
Powering base stations
This section describes tips for powering base stations, as well as the component connection
sequence you need to use to properly power base stations.
Powering tips
• It is recommended that you use a redundant power supply for base stations.
• Each base station requires 48 volts DC at 3.0 amps maximum.
• The ground of the power can be either negative or positive. The 48 volt power input to the
base station is floating, so either the positive or negative can be grounded.
• Power input is polarity sensitive, so be sure you connect V+ and V- properly.
• Depending on the type of equipment you own, supply power to the Ethernet switch and
backbone network equipment.
• It is recommended that you use an uninterruptable power supply (UPS).
Tips for sizing the UPS include:
• Size the voltage and amperage of the power supply according to the number of base
stations at your cell site.
• Size the UPS according to the efficiency of the DC power supplies and power
requirements of the other ancillary equipment, such as the Ethernet switch and
backbone network equipment.
• Consider the time you want to allow the system to operate on the UPS.