User Manual

Purpose of Optimization
5/21/04 1X SC4812T–MC BTS Optimization/ATP 1-11
DRAFT
Why Optimize?
Proper optimization and calibration ensures that:
S Accurate downlink RF power levels are transmitted from the site.
S Accurate uplink signal strength determinations are made by the site.
What Is Optimization?
Optimization compensates for the site-specific cabling and normal
equipment variations. Site optimization guarantees that the combined
losses of the cables and the gain/loss characteristics and built-in
tolerances of each BTS frame do not accumulate and cause improper site
operation.
What Happens During
Optimization?
Overview – During optimization, the accumulated path loss or gain is
first determined for each RF transmit path in the BTS. These transmit
path loss or gain values are then stored in a database along with RF
receive path default values.
RF path defintions – For definitions of the BTS transmit (TX) and
receive (RX) paths, see “What is Bay Level Offset Calibration?” in the
Bay Level Offset Calibration section of Chapter 3.
In this publication, all models of the Broad Band
Transceiver (BBX) board usable in this BTS, are
generically identified as BBX, unless otherwise specified.
Also, all models of the Multi–Channel CDMA (MCC)
cards usable in this BTS, are generically identified as
MCC, unless otherwise specified.
NOTE
RF paths and transceiver optimization – Twelve of the BBX boards in
each Combined–CDMA Channel Processor (C–CCP) shelf are
optimized to specific RX and TX antenna connectors. The last BBX
board provides redundancy for BBX boards 1 through 12, and is
optimized to all antenna connectors. A single optimization value is
generated for each complete path. This eliminates the accumulation of
error that would occur from individually measuring and summing the
gain and loss of each element in the path.
Using RF path gain/loss values – BTS equipment factors in the derived
optimization values internally to adjust transceiver power levels, leaving
only site–specific antenna feedline loss and antenna gain characteristics
to be factored in by the CFE when determining required site Effective
Radiated Power (ERP) output power levels.
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