User's Manual
Table Of Contents
- SC 4812T-MC vs SC 4812T BTS Read Me First (Comparison)
- Contents
- Chapter 1 Manual Overview and BTS General Information
- Chapter 2 Inter-Frame Cabling
- Inter-Frame Cabling
- Cable Connections
- Cabling Diagrams and Descriptions
- Alarm / Span Cabling
- Equipment Compliance
- BTS System Timing Options
- RF Global Positioning Satellite (RF GPS) Cabling
- Remote Global Positioning Satellite (RGPS) Cabling
- Low Frequency Receiver / High Stability Oscillator (LFR/HSO) Cabling
- BTS Antenna Configuration
- BTS 60 Degree Sector (6 Sector) Transmit Path Cabling
- BTS 60 Degree Sector (6 Sector) Receive Path Cabling
- BTS 120 Degree Sector (3 Sector) Transmit Path Cabling
- BTS 120 Degree Sector (3 Sector) Receive Path Cabling
- Earth Ground Cabling
- BTS Power Cabling
- Chapter 3 Expansion Frame Cabling and Installation
- Expansion Frame (+27 V BTS Configuration)
- Expansion Frame Inter-Frame Cabling
- Expansion of the +27 V Frame
- RF GPS Expansion Installation
- Remote GPS Distribution Expansion
- High Stability Oscillator Expansion (HSOX)
- Local Area Network (LAN) Expansion Installation
- Setting Frame C-CCP Shelf Configuration Switch
- Chapter 4 Optional Equipment
- Optional BTS Equipment Identification
- BTS Antenna Configuration
- BTS 60 Degree Sector (6 Sector) Transmit Path Cabling
- BTS 60 Degree Sector (6 Sector) Receive Path Cabling
- BTS 120 Degree Sector (3 Sector) Transmit Path Cabling
- BTS 120 Degree Sector (3 Sector) Receive Path Cabling
- 3 Sector Non-Duplexed Cabling
- 3 Sector Duplexed
- 6 Sector Duplexed
- Chapter 5 What's Next and Site Cleanup
- Appendix A Carrier Add Instructions
- Index
RF GPS Expansion Installation
Mar 2003
1X SC 4812T-MC BTS Hardware Installation - Software Release R2.16.1.x
CONTROLLED INTRODUCTION
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RF GPS Expansion Installation
GPS Expansion
The Global Positioning System (GPS) is used by Motorola as the
primary means to synchronize all base stations in a CDMA cellular
system. The GPS signal is the input to the CSM, which develops the
timing references for the Base Transceiver system (BTS). Every BTS at
a site requires a GPS input.
On some versions of the SC 4812T product, GPS timing is provided by
a built-in dedicated RF GPS receiver module installed on the CSM. On
BTSs equipped with redundancy, two (2) CSMs are installed.
On some versions of the SC 4812T product, GPS timing is provided by
an optional Remote GPS receiver (RGPS). The RGD card accepts timing
information in digital format from the RGPS head and distributes it
within the BTS, and to other Expansion cabinets by a small digital cable.
The procedure for RGPS is covered in a separate section.
Customer Equipment Considerations and System Constrains
In order to share RF GPS signals, customer equipment external to the
BTS must be carefully designed to ensure that overall performance is not
degraded. Both the gain and the noise of the complete system affect the
performance and the A/D converter in the GPS receiver. A typical
diagram of a system to feed multiple BTSs from one GPS antenna is
shown in Figure 3-7.
RF RGPS Expansion Installation Considerations
Following are recommendations for the RF GPS distributing amplifier
method:
S The maximum GPS system NF is 4 dB, per OnCore Technical
Application Note (CSM GPS Vendor).
S GPS distributed amplifier is acceptable, but only with Motorola
recommended parts.
S Recommended amplifier model number is HP58516A (4–way).
S Must have surge protection before the distribution amplifier
(PolyPhaser number is IS–MR50LNZ–6–MA).
S Maximum cable loss between GPS antenna and BTS is 4.5 dB.
S Maximum cable length difference between the 4:1 splitter to any
cabinet is 8 meters.
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