Service Manual

GSM-204-323
RF overview and RF test function
31st Oct 01
Technical Description: Horizon macro outdoor
68P02902W02-A
CONTROLLED INTRODUCTION
Tech. 5–5
Tx block
There are up to three Tx blocks, each block serving two CTUs.
Tx blocks filter the transmit signal for the required Tx band. Tx blocks also use
filters to enable the Rx frequency signal to be passed to the SURF, if one
antenna is used for both Tx and Rx signals.
RF loopback
test function
The loopback test function is primarily used to identify faults when the RF
system has failed. The loopback test function enables a diagnostic capability at
the OMC-R, by creating a test signal to identify if the fault is either:
 Software (that the OMC-R can correct).
 Particular hardware (CTU or SURF).
The result is a reduction in site assessment visits, and avoidance of
unnecessary visits when hardware is functioning correctly.
NOTE
The RF loopback test feature available on the
Horizon
macro is not available on previous generations of
equipment.
RF loopback
hardware
The RF loopback test function is essentially a hardware capability built into the
CTU and the SURF. Software instructions activate the test hardware, to route
test signals through the RF system.
RF loopback
software
operation
When installed with suitable software, GSR5 or later, the OMC-R can operate
the loopback test functions, and receive the results of the tests.