ALM-4708 Clock Reference Abnormal Alarm

Description

This alarm is reported if the upper level clock cannot be locked.

Attribute

Alarm ID Alarm Severity Alarm Type
4708 Warning Fault

Parameters

ID Name Meaning
1 Site No.

Number of the site where the faulty board or module is located

Value range: 0-2047
2 Board Type

Number of the type which the faulty board belongs to.

64:DTMU/DOMU

87:GTMU
3 Board No.

Number of the fault board

0-7:DTMU/DOMU/GTMU
4 PassNo

Number of the passage where the faulty board is located.
5 SubLink No.

Alarm sub-category number

255:None
6 Cell Index

Index of the cell where the board or module is located

0-2047: Cell index of the faulty cell in the data configuration

65535: None
7 Site Type

Type of the site where the faulty board is located.

12:BTS3012;

13:BTS3006C;

14:BTS3002E;

15:BTS3012AE;

16:BTS3012 II;

17:DBS3900 GSM;

18:BTS3900 GSM;

19:BTS3900A GSM;
8 RackNo

Number of the rack where the faulty board is located.
9 BoxNo

Number of the subrack where the faulty board is located.
10 SlotNo

Number of the slot where the faulty board is located.
11 Site Name

Site Name
12 Alarm Attribute

Alarm Character

0:Normal

1:Transient Count

Impact on the System

The faulty BTS clock has deviation with other BTS clocks, causing abnormal HO(handoff), network selection and reselection.

System Actions

None

Possible Causes

  • Faulty clock module.
  • Abnormal clock of the transmission link.
  • Abnormal upper level clock reference.

Procedure

  1. Based on the alarm information, check for other correlated alarms.

    NOTE:

    It takes 40 minutes to three hours to clear the alarm, depending on the transmission conditions.

    1. Run the LST ALMAF command on the MML client. Check for ALM-4714 E1/T1 Local Alarm or ALM-4716 E1/T1 Remote Alarm.

      Y => ALM-4714 E1/T1 Local Alarm or ALM-4716 E1/T1 Remote Alarm is reported on the LMT. Go to step b.

      N => ALM-4714 E1/T1 Local Alarm or ALM-4716 E1/T1 Remote Alarm is not reported on the LMT. Go to procedure 2.

    2. Clear the alarm according to the associated handling suggestions in ALM-4714 E1/T1 Local Alarm or ALM-4716 E1/T1 Remote Alarm. Then, check whether the alarm is cleared.

      Y => The alarm is cleared. No further action is required.

      N => The alarm is not cleared. Go to procedure 2.

  2. Check the transmission link clock of the BTS.
    1. If the BTS uses the BSC clock, go to step b. If the BTS uses the IP clock, go to procedure 6.
    2. Rectify the transmission fault between the BTS and the BSC. Then, check whether the alarm is cleared.

      Y => The alarm is cleared. No further action is required.

      N => The alarm is not cleared. Go to step b.

    3. Measure the frequency offset of the clock signals in the BTS transmission link by using a frequency meter. Check whether the frequency offset is greater than 2 Hz.

      Y => The frequency offset is equal to or greater than 2 Hz. The transmission clock is abnormal. Go to step c.

      N => The frequency offset is less than 2 Hz. The transmission clock is normal. Go to procedure 4.

    4. Check the transmission from the BTS to the BSC. Check for bit errors by using a BER tester.

      Y => The bit errors exist. Go to procedure 3.

      N => There is no bit error. Go to procedure 4.

  3. Contact the maintenance engineers to check for the transmission fault.

    Y => The transmission fault exists. Rectify the transmission fault and end the alarm handling.

    N => There is no transmission fault. Go to procedure 4.

  4. Check the main controlling module.
    1. Reset the main controlling module. Then, check whether the alarm is cleared.

      Y => The alarm is cleared. No further action is required.

      N => The alarm is not cleared. Go to step b.

    2. Replace the main controlling module. Then, check whether the alarm is cleared.

      Y => The alarm is cleared. No further action is required.

      N => The alarm is not cleared. Go to procedure 5.

  5. Reset the site in level 4. Then, check whether the alarm is cleared.

    Y => The alarm is cleared. No further action is required.

    N => The alarm is not cleared. Contact Huawei Customer Service Center.

  6. Check the IPCLK configuration sent by the BSC.
    1. Check whether the IPCLK configuration (IP address and port number of the IP clock server) sent by the BSC is correct.

      Y => The IPCLK configuration is correct. Go to step c.

      N => The IPCLK configuration is incorrect. Go to step b.

    2. Modify the IPCLK configuration and send the correct IPCLK configuration to the BTS. Then, check whether the alarm is cleared.

      Y => The alarm is cleared. No further action is required.

      N => The alarm is not cleared. Go to step c.

    3. Check whether the connection between the BTS and the clock server is normal and whether the intermediate equipment is correctly configured.

      Y => The connection is normal and the configuration is correct. Go to step e.

      N => The connection is abnormal. Go to step d.

    4. Correctly connect the BTS and the clock server and correctly configure the intermediate equipment. Then, check whether the alarm is cleared.

      Y => The alarm is cleared. No further action is required.

      N => The alarm is not cleared. Go to step e.

    5. Check whether the clock server runs normally and whether the configuration of the clock server is correct.

      Y => The clock server runs normally and the configuration of the clock server is correct. Contact Huawei Customer Service Center if the alarm persists.

      N => The clock server runs abnormally or the configuration of the clock server is incorrect. Go to step f.

    6. Modify the configuration of the clock server. Ensure that the clock server runs normally and sends the correct configuration. Then, check whether the alarm is cleared.

      Y => The alarm is cleared. No further action is required.

      N => The alarm is not cleared. Go to step g.

    7. Reset the main controlling module. Then, check whether the alarm is cleared.

      Y => The alarm is cleared. No further action is required.

      N => The alarm is not cleared. Go to step h.

    8. Replace the main controlling module. Then, check whether the alarm is cleared.

      Y => The alarm is cleared. No further action is required.

      N => The alarm is not cleared.Contact Huawei Customer Service Center.

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