User Manual

Troubleshooting: C–CCP Backplane
5/21/04 1X SC4812T–MC BTS Optimization/ATP 6-13
DRAFT
Introduction
The C–CCP backplane is a multi–layer board that interconnects all the
C–CCP modules. The complexity of this board lends itself to possible
improper diagnoses when problems occur.
Connector Functionality
The following connector overview describes the major types of
backplane connectors along with the functionality of each. This
information allows the CFE to:
S Determine which connector(s) is associated with a specific problem
type.
S Isolate problems to a specific cable or connector.
Primary “A” and Redundant “B” Inter Shelf Bus Connectors
The 40 pin Inter Shelf Bus (ISB) connectors provide an interface bus
from the master GLI to all other GLIs in the modem frame. Their basic
function is to provide clock synchronization from the master GLI to all
other GLIs in the frame.
The ISB also provides the following functions:
S Span line grooming when a single span is used for multiple cages.
S MMI connection to/from the master GLI to cell site modem.
S Interface between GLIs and the AMR (for reporting BTS alarms).
Span Line Connector
The 50–pin span line connector provides a primary and secondary (if
used) span line interface to each GLI in the C–CCP shelf. The span line
is used for MM/EMX switch control of the Master GLI and also all the
BBX traffic.
Primary “A” and Redundant “B” Reference Distribution
Module Input/Output
The Reference Distribution Module (RDM) connectors route the 3 MHz
reference signals from the CSMs to the GLIs and all BBXs in the
backplane. The signals are used to phase lock loop all clock circuits on
the GLIs and BBX boards to produce precise clock and signal
frequencies.
Power Input (Return A, B, and C connectors)
For –48 V configuration – Provides a –48 volt input for use by the
power supply modules.
For +27 V configuration – Provides input for regulated +27 Volts.
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