Specifications

Ba y Lev el Offset Calibr ation Appendix E: Optimization and Calibr ation Procedures
Bay Level Offset Calibration
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T o avoid over -driving the XMIs, the BLO for UBS must be -2 dB or greater .
Introduction
Bay Level Offset (BLO) calibration is used to optimize non -standard UBS installations. F actory
calibration of the UBS components assures proper TX performance of the UBS system in all
installations that use Motorola supplied hardware in the TX path. In the event of a non -standard
installation, BLO calibration can be used to compensate for TX path loss variations due to
non -standard equipment.
RF Path Bay Level Offset Calibration
Calibration identifies the accumulated gain in every transmit path (sector–carrier) at the UBS
site and stores that value in a BLO data base calibration table in the LMF .
F or single frames, each receive path starts at an RX antenna port and terminates at the UBS .
Calibration identifies the accumulated gain in every transmit path at the UBS site and stores
that value in a BLO database. Only those slots (sectors) actually equipped in the current NEC
file are tested.
When to TX Audit
TX Audit will be performed:
• A fter initial UBS installation
• A fter UBS replacement
TX Path Calibration
The TX P ath Calibration assures correct site installation, cabling, and the first order functionality
of all installed equipment. The proper function of each RF path is verified during calibration.
The external test equipment is used to validate/calibrate the TX paths of the UBS .
E -6 68P09283A63 -5
FOA A UG 2007