User's Manual Part 2

Bay Level Offset Calibration – continued
6-80 1X SC480 BTS Hardware Installation, Optimization/ATP, and FRU MAY 2004
PRELIMINARY
TX Calibration and the LMF
The LMF Tests > TX > TX Calibration... and Tests > All Cal/Audit...
selections perform TX BLO calibration testing for installed BBX(s). The
All Cal/Audit... selection initiates a series of actions to perform TX
calibration, and if calibration is successful, download BLO and perform
TX audit. The TX Calibration... selection performs only TX
calibration. When TX Calibration... is used, BLO download and TX
audit must be performed as separate activities. The CDMA Test
Parameters window which opens when TX Calibration... or All
Cal/Audit... is selected contains several user–selectable features which
are described in the following subsections.
Rate Set Drop–down Pick List
The Rate Set Drop–down Box is enabled if at least one MCC card is
selected for the test. The available options for TX tests are 1 = 9600, and
3 = 9600 1X. Option 3 is only available if 1X cards are selected for the
test. The available transfer rate options for RX tests are 1 = 9600 and
2 = 14400. Option 2 is only available if no 1X cards are selected.
Verify BLO Check Box
In both the TX Calibration and All Cal/Audit dialog boxes, a Verify
BLO check box is provided and checked by default. After the actual TX
calibration is completed during either the TX Calibration or All
Cal/Audit process, the BLO derived from the calibration is compared to
a standard, acceptable BLO tolerance for the BTS. In some installations,
additional items may be installed in the transmit path. The additional
change in gain from these items could cause BLO verification failure
and, therefore, failure of the entire calibration. In these cases, either the
Verify BLO check box should be unchecked or the additional path
losses should be added.
Single–Sided BLO Check Box
An acceptable range of BLO values for each type of BTS is established
to allow for tolerance variations in all the components of the RF chain.
This acceptable range, 42+5 dB for example, is a much wider tolerance
than necessary for the BBXs. Single–Sided BLO calibration restricts the
allowable BLO variations to the lower half of the range (i.e., 37 to 42
dB). Because this is a much more stringent tolerance, calibrations run
with Single–Sided BLO are more likely to fail and should only be
attempted by an experienced CFE.
The Tests > TX > TX Calibration... menu window has a Test Pattern
pull–down menu. This menu has the following choices:
S Standard – performs calibration or audit using pilot, paging, synch,
and six traffic channels with IS–97–specified gain. This pattern setting
should be used for all non–in–service calibrations and audits. Using
this pattern setting requires the selection of both a BBX and at least
one MCC.
S Pilot (default) – performs calibration using only the pilot channel.
This pattern setting should be used for in–service calibrations, and
requires selection of only a BBX.
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