User Manual
Bay Level Offset Calibration – continued
3-84 1X SC4812T–MC BTS Optimization/ATP 5/21/04
DRAFT
Transmit (TX) Bay Level Offset (BLO) Specifications –
SC4812T–MC TX BLO specifications for different BTS sector
configurations are as follows:
Table 3-35: Transmit (TX) Bay Level Offset (BLO) Specification
Single Sided Double Sided
800 MHz 3–Sector > 35dB 40dB +/– 5dB
800 MHz 6–Sector > 38dB 43dB +/– 5dB
1.9 GHz 3–Sector > 30dB 35dB +/– 5dB
1.9 GHz 6–Sector > 33dB 38dB +/– 5dB
To set the expected values see Table 3-36.
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
In both the TX Calibration and All Cal/Audit dialog boxes, a Verify
BLO checkbox 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 checkbox should be unchecked or the additional path losses
should be added into each applicable sector using the
Util > Edit > TX Coupler Loss... function.
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