Product Info

METRO CELL OUTDOOR (DE/RE) CDMA BTS RADIO DEVELOPMENT
PROPRIETARY CELL SITE REQUIREMENTS
Issue 01 Stream 00 - 15 - Feb. 2001
7.0 GPS Receiver
Timing and frequency reference information provided by the GPS receiver is critical to the
proper operation of Metrocell subsystem. One or two GPS antennas may be connected. The GPS
antenna receives the signals from multiple satellites, and the signal is supplied to the GPS
receiver in the Metrocell via a coaxial cable. Precautions should be taken to ensure that the GPS
antenna is clear of obstructions and interference.
The antenna should be installed to provide the best view of the entire sky. A complete view of
the sky from horizon to horizon will enable the receiver to observe as many GPS satellites as
possible. This allows the GPS receiver to select the best combination of GPS satellites for best
performance. If the GPS antenna must be installed with a limited view of the sky, it may not be
able to track a sufficient number of satellites to determine its position. The GPS receiver must
track at least 4 satellites simultaneously for some period of time in survey mode. Once the GPS
receiver has an accurate fix on its location, it can maintain accurate timing signals to the BTS
while tracking only one satellite.
The maximum distance between Metrocell and GPS antenna is set by the maximum allowable
cable loss of? dB. The cable length and type is required by the GPS receiver for determining the
delay from antenna to the receiver.