User's Manual

5-18
Figure 5 - 7 Troubleshooting DS3 Radio RCV Alarms
DS3 Frame Loss
DS3 Buffer Spill
DS3 Degraded
DS3 AIS Detect
DS3 AIS Insert
I/O Interface cannot recover framing from signal from RCVR module.
1. Is DS3 AIS Detect alarm on?
Yes, check for upstream XMTR
DS3 AIS Detect alarm.
If XMTR
DS3 AIS Detect alarm is on,
troubleshoot external MUX equipment at XMT end.
If not, troubleshoot upstream XMTR. No, go to 2.
2. Is DS3 AIS Ins alarm on?
Yes, check for upstream XMTR alarms. If any XMTR alarm is on,
troubleshoot upstream XMTR. No, go to 3.
3. Is radio hot-standby?
Yes
A. Are A and B alarmed?
Yes, troubleshoot XMTR. No, go to B.
B. Remove/replace RCVR module.
C. Remove/replace alarmed DS3 I/O Interface.
AIS (blue signal), inserted at MUX
(external to the radio) has been
detected by DS3 I/O INTFC RCV
circuits.
Troubleshoot external MUX equipment
(fault is not in radio).
DS3 input data being written to elastic
buffer on DS3 I/O interface is a different
rate than data being read from elastic
buffer.
MDR-1087
05/25/07
LOS has been detected at RCV input of DS3 I/O INTFC
and AIS (blue signal) is being inserted. Check for LOS at
XMTR end of hop.
If not:
1. Check for upstream XMTR alarms. Any XMTR alarms?
Yes, troubleshoot XMTR
No, go to 2.
2. Replace RCVR module on alarmed side.
3. Replace alarmed DS3 I/O INTFC module.
Signal from RCVR module (input to DS3
I/O INTFC) has exceeded provisioned
BER threshold (typical fade condition).
Is DS3 Frame Alarm also on?
Yes, troubleshoot DS3 Frame Alarm.
No, and no-fade condition confirmed
1. Replace RCVR module.
2. Replace alarmed DS3 I/O
INTFC module.