COMBA CriticalPoint V3 7 BDA - Gibraltar Drive, Milpitas, CA 95035 | +1 408 526 0180

CRITICALPOINT 700/800MHZ BDA/DAS/BBU V3 USER MANUAL
©2024 Comba Telecom. All Rights Reserved.
568 Gibraltar Drive, Milpitas, CA 95035 | +1 408 526 0180
Rev. 1-0-2 Rev. Date: 11-1-2024
Page: 180
Oscillation Detection Process
Once an oscillation is detected, the system will measure the current isolation. If the gain > isolation – 20,
system will reduce the gain and generate an Oscillation Gain Reduction alarm. If gain < isolation - 20, the
system moves to the T2 judgement process to monitor the parameters. If oscillation continues to be
detected, the system will shut down and generate an Oscillation Shut Down Alarm. See Figure 156 and
Table 23 below for a detailed explanation of the Oscillation Detection parameters.
Figure 156: Oscillation Detection Alarm Parameters
Table 23: Oscillation Detection Parameters Explained
Default
Osc. Detection Switch
OFF
The switch to turn on or off Oscillation Detection
UL Switch
ON
The switch to turn on or off the UL Oscillation Detection
DL Switch
OFF
The switch to turn on or off the DL Oscillation Detection
UL_OSC_TH
-70
UL Oscillation Threshold Level. Refer to OSC_T1 (2s)
DL_OSC_TH
-30
DL Oscillation Threshold Level. Refer to OSC_T1 (2s)
OSC_T1(2s)
20
The Oscillation Detection Process will start if UL or DL
composite input power is higher than UL_OSC_TH or
DL_OSC_TH for longer than OSC_T1 (2s).
OSC_T2(min)
(T2 Judgement Process)
10
If the input power is still higher than UL_OSC_TH or
DL_OSC_TH after isolation measures OK, the system will
confirm the high input status and restart the oscillation
detection at every OSC_T2 (min) period
OSC_T2_CycleNum
12
The total number of times the system will retry the detection
process if isolation is measuring OK, but input power is still
high. If high input is cleared, the process will end. If the
retry attempts > OSC_T2_CycleNum value, the system will
generate PA shutdown and turn OFF the RF Switches
DL700M Last Isolation Mea.
The last measured isolation for 700MHz band for reference
DL800M Last Isolation Mea.
The last measured isolation for 800MHz band for reference
Oscillation Shutdown(700MHz)
Enabled
700 Band has been shut down; failure to mitigate oscillation
Oscillation Shutdown(800MHz)
Enabled
800 Band has been shut down; failure to mitigate oscillation
Osc. Gain Reduction(700MHz)
Enabled
700MHz band Gain is reduced due to oscillation
Osc. Gain Reduction(800MHz)
Enabled
Gain is reduced due to oscillation for 800MHz band