User's Manual

Purpose of the Optimization
May 2000
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SC 4812T CDMA BTS Optimization/ATP
Why Optimize?
Proper optimization and calibration assures:
 Accurate downlink RF power levels are transmitted from the site.
 Accurate uplink signal strength determinations are made by the site.
What Is Optimization?
Optimization compensates for the site-specific cabling and normal
equipment variations. Cables that interconnect the BTS and Duplexer
assemblies (if used), for example, are cut and installed at the time of the
BTS frame installation at the site. Site optimization guarantees that the
combined losses of the new cables and the gain/loss characteristics and
built-in tolerances of each BTS frame do not accumulate, causing
improper site operation.
Optimization identifies the accumulated loss (or gain) for all receive and
transmit paths at the BTS site, and stores that value in a database.
 The RX path for the starter frame starts at the ancillary equipment
frame RFDS RX directional coupler antenna feedline port, through the
ancillary equipment frame RFDS RX directional coupler antenna
feedline port, through the RX input port on the top of the frame,
through the bandpass filter, Combiner Input/Output (CIO) card,
Multicoupler Preselector Card (MPC), and additional splitter circuitry,
ending at a Code Division Multiple Access (CDMA) Channel
Processor (C–CCP) backplane Broad Band Transceiver (BBX2) slot in
the C–CCP shelf.
 The RX path for the expansion frame starts at the ancillary equipment
frame RFDS RX directional coupler antenna feedline port, through the
ancillary equipment frame RFDS RX directional coupler antenna
feedline port, through the RX input port on the top of the starter
frame, through the bandpass filter and CIO card, out the expansion
port at the top of the starter frame, through the expansion cable to the
expansion port on the expansion frame, through the Expansion
Multicoupler Preselector Card (EMPC) and CIO, ending at a Broad
Band Transceiver (BBX2) slot in the C–CCP shelf.
 The TX path starts at the BBX2, through the C–CCP backplane slot,
travels through the LPA/Combiner TX Filter and ends at the top of the
RFDS TX directional coupler antenna feedline port (CDMA), installed
on the ancillary equipment frame. If the RFDS option is added, then
the TX path continues and ends at the top of the RFDS TX directional
coupler antenna feedline port installed in the ancillary equipment
frame. The TX paths are identical for the starter and expansion
frames.
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