426 Switchback after Trx Passage Mutual Aid in a Cell

Description

[1]This alarm is reported when the BCCH is switched back to the initial TRX under the following conditions: the BSC detects that the access binded with primary BCCH resumes to normal operation, and the management status of the main BCCH is Unlocked, and the switchback is allowed in the cell. [2]This alarm is also reported when a forced switchback occurs due to data configuration.

Attribute

Alarm ID	Alarm Severity	Alarm Type
426	Major	Event

Parameters

ID	Name	Meaning
1	Cell Index.	Index of the cell where BCCH TRX mutual aid occurs.
2	Cell Name	Name of the cell where BCCH TRX mutual aid occurs.
3	Cell CGI	Cell Global Identifier of the cell where BCCH TRX mutual aid occurs.
4	Site No.	Number of the site where the cell generating an alarm is located
5	Site Name	Name of the site where the cell generating an alarm is located
6	Alarm Attribute	0=Normal, Alarms period are longer than the Transient Threshold. 1=Transient Count, The times and the period of the alarms whose periods are shorter than the Transient Threshold are summed up. If the sum result is longer than the Alarm Occurrence Period Threshold or Alarm Occurrence Times Threshold, an alarm so called Transient Count Alarm is triggered. Because Transient Count Alarm is based on accumulative result, the recovery of the alarm may occur at least one Summing Cycle later. The Summing Cycle can be query by MML "LST STATSLDWIN".

Impact on the System

The BCCH TRX switches back to the initial passage, and restores the services after a short interruption

System Actions

The BTS binds the path initially configured for the BCCH TRX back to BCCH TRX.

Possible Causes

The faulty passage where the BCCH TRX is initially configured restores normal state.
Forced switchover is performed due to configuration.

Procedure

Check whether the switchback is caused by manual troubleshooting.
Y=> Go to 3.

N=> This indicates that the initial TRX is unstable or has transient faults. Go to 2.
Check whether the primary BCCH is idle after the BCCH mutual aid.
Y=> The primary BCCH is idle. Go to 3.

N=> The primary BCCH is not idle. The switchover of the main BCCH fails. Please contact Huawei Customer Service Center andreplace the faulty TRX.
Wait for 15 minutes and then launch the LMT. Check whether the alarm 425 Trx Passage Mutual Aid in a Celloccurs.
Y=> The alarm 425 Trx Passage Mutual Aid in a Cell occurs. Clear alarm 425 Trx Passage Mutual Aid in a Cell according to its relevant handling suggestions. In addition, the occurrence of the mutual aid and switchback shows that the BCCH-carried TRX is unstable. Please contactHuawei Customer Service Center and replace the faulty TRX.

N=> The alarm 425 Trx Passage Mutual Aid in a Cell does not occur. The alarm handling is complete.