User's Manual

Purpose of the Optimization
68P09258A31–A
Oct 2003
1X SCt 4812T BTS Optimization/ATP
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Purpose of the Optimization
Why Optimize?
Proper optimization and calibration assures:
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. 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.
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 definitions – For definitions of the BTS transmit (TX) and
receive (RX) paths, see “Bay Level Offset Calibration” in Chapter 3.
RF paths and transceiver optimization – Six of the seven Broad Band
Transceiver (BBX) boards in each CCP shelf are optimized to specific
RX and TX antenna connectors. The seventh BBX board acts in a
redundant capacity for BBX boards 1 through 6, 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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