User Manual
ADCP-75-192 • Issue D • October 2005 • Section 7: Autonomous Software Functionality
Page 7-4
2005, ADC Telecommunications, Inc.
• If the channel faults are confined to channels 1-4, then either the HDC #1 or the FSC
module is declared to be at fault.
• If channel faults are confined to channels 5-8, then either the HDC #2 or the FSC
module is declared to be at fault.
6.2 RAN
As the forward RF detectors in the RAN are geared for accuracy at high-power outputs, they
are not suited for the power levels required for FGC non-destructive tests. However, the
digital detectors are monitored. The fault detection process in the RAN will generate a fault if
the gain drops by 10 dB or if pathtrace is lost at the digital path. This check is performed as
part of FGC during the normal course of gain management. See trouble shooting guide for
details.
7 REVERSE CONTINUITY
Reverse Continuity Management (RCM) is a software function that is a subset of Tenant
Processing and is responsible for ensuring that the reverse RF paths for each tenant-sector are
functioning properly and are able to pass signals.
The RCM process runs continuously on a periodic basis (once per minute) and reports any path
failures as faults in the RGC MIB. If fault conditions are no longer present, then the fault
indication will be cleared. Typical events that will clear a fault include:
• Replacement of failed module
• Power failure, followed by power restore
• Autonomous action (E.g. PLL out of lock, re-tune, module okay)
• Intermittent failure.
• Disabling the RDC test tones
The following descriptions outline the logical process by which system level faults are
detected and isolated, where possible, to a particular module. Noise and an RF tone are
monitored in the reverse direction, in order to confirm an operational reverse path. Noise is
detected using a Power Measurement in the HUB SIF module. The tone is detected using an
FFT in the HUB SIF and the BIM RF Output detector. If measured values fall below specified
threshold values, then faults will be generated.
7.1 Noise
The front-end noise will be monitored by reading the noise power value from the reverse
channels in the RAN SIF module belonging to the tenant-sector being analyzed. The in-band
noise power (N) and total signal power (S+N) will be measured and analyzed in the SIF using
an FFT analysis, as follows: