User's Manual

Bay Level Offset Calibration68P09255A69-3
Aug 2002
1X SC4812ET Lite BTS Optimization/ATP Software Release 2.16.1.x
PRELIMINARY
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frame through the RX expansion out connectors (RX EXPANSION
1A, 2A, or 3A in Figure 1-9 or Figure 1-10). The signal travels
through the inter-frame diversity RX cables, into the RX expansion in
ports (RX EXPANSION 1B, 2B, or 3B in Figure 1-9 or Figure 1-10)
of the companion frame, through the Expansion MPC (EMPC) in
SCCP cage slot MPC-2, the CIO, and terminates at a backplane BBX
slot in the SCCP shelf.
 RFDS sampling paths - Directional couplers for RFDS signal
sampling are integral to the SC4812ET Lite transmit and receive paths
in the DRDCs and TRDCs. Cables connect from these directional
couplers to the RFDS input connectors.
Component Verification During Calibration
TX Path Calibration
TX path calibration supports verification of correct BTS installation, RF
cabling installation and performance, functionality of all equipment
installed in the transmit RF chain, and the proper functioning of each
transmit RF path. External test equipment is used to calibrate and audit
the TX paths of the BTS.
RX Path Calibration
RX path calibration is not required or supported on CDMA BTS
systems. Default RX calibration values are written to the RX calibration
data files during the TX calibration process. RX functionality is verified
during Frame Erasure Rate (FER) testing.
When to Calibrate
Calibration to determine BLO:
1. Is required after initial BTS installation.
2. Must be done once each year for an operational BTS site.
3. Is recommended by Motorola for all associated RF paths after
replacing any of the following components:
- BBX card
- SCCP shelf
- CIO card
- CIO-to-LP A trunking module RF cable
- LPA trunking module
-LPA
- Trunking module-to-TX filter/filter combiner RF cable
- TX filter or TX filter combiner
- TX filter/filter combiner-to-DRDC/TRDC cable
- DRDC or TRDC
BLO Calibration Data File
During the calibration process, the LMF creates a calibration (CAL) data
file where BLO values are stored. After calibration has been completed,
these offset values must be downloaded to the BBXs using the LMF
BLO download function. A detailed description of the file organization
and content is provided in the following paragraphs
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