No Master TF in Cluster

2G GSM
1

Dear Experts,

I have an alarm in one of the sites which is working under baseband for all the 3 technologies 2G/3G.4G 2G and 3G is mixed mode using same rru and 4G is stand alone, 2G is not coming up, and I have the below-mentioned alarm in the BSC .

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help me to fix this

Thanks in advance

BR//

1 Like
2

Hi @Mani, if got it right this is sync over CPRI issue.
Check from BB side:
Synchronization=1,RadioEquipmentClock=1 nodeGroupRole 2 (SYNC_PROVIDER)
and Node Group Synchronization in IDB (in case DUG).

1 Like
3

Hi,

Thanks for your reply,This node is a BB node and works with 2G/3G and 4G in the same BB, also the radio for 2G and 3G is a mixed mode. So there is no other BB or DUG on the site except this one and only BB.

BR//

4

Why “radio for 2G and 3G is a mixed mode” if there is no other DU/BB?

5

Since they are the same band it is mixed mode and the 2G was working before, but suddenly it went down.

6

is there any way to modify the TF in the BSC? If yes please give the procedure.

Thanks

7

Try to turn off mixed mode set FieldReplaceableUnit=RRU isSharedWithExternalMe false

8

Thanks, I did it but still 2G is not coming up .

BR//

9

Is there any alarm on BB/BSC? Did you try to restart BB, RXBLI->RXESE->RXESI->RXBLE for all RXSTG of that BB?

10

Yes I did the restart in both BB and BSC but still the same and none of the TF is coming up for all the 3 TG.

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image845×207 9.87 KB

11

BB has RET alarm and BSC has TF alarm

12

I have no idea, maybe it is HW problem in BB.

13

It happens because the 2G shares radio with the 3G. Either both share the same radio with the 3G being on BB while the 2G is on DUG or both share radio and are connected to the same baseband. The alarm shows up when the 3G restores and the 2G is not in sync with the 3G due to clock error, causing the 2G not to be taking traffic.

To fix the issue, follow the sample script below:

rxbli:mo=rxstg-196,force;
rxese:mo=rxstg-196;

Log onto the BB

get . rfb ----- to know which radio the 2G sector is connected to. 
st rru  
bl rru-5; 
deb rru-5;
acc rru-5 restartunit ; 2 ; 3 ; trx
st field
acc 113 restartunit ; 2 ; 3 ; G900_B;
rxesi:mo=rxstg-196;
rxble:mo=rxstg-196 
rxmsp:mo=rxstg-196; ---- for all sectors

If trxes are missing, run the script:

rxbli:mo=rxstg-196,force;
rxese:mo=rxstg-196;
rxesi:mo=rxstg-196;
rxble:mo=rxstg-196;

I hope this helps.

1 Like
14

1. Synchronization Issues:

  • Check Synchronization Status: Verify the synchronization status of the BSC, RRU, and any other relevant equipment. Look for discrepancies in timing or phase offsets.
  • Inspect Cable Connections: Ensure all synchronization cables (e.g., GPS, 1PPS) are securely connected and in good condition.
  • Verify Clock Source: Confirm that the correct clock source is configured for the BSC and RRU.
  • Check Network Element Configuration: Review the configuration of the BSC and RRU for any synchronization-related parameters that might be incorrect.
  • Examine Log Files: Analyze log files for any error messages related to synchronization.

2. Hardware Failures:

  • Inspect Equipment: Physically examine the BSC and RRU for any signs of damage or malfunction.
  • Check Power Supply: Verify that the power supply to both units is stable and sufficient.
  • Replace Faulty Components: If any hardware components are found to be defective, replace them.

3. Software Issues:

  • Check Software Versions: Ensure that the BSC and RRU are running compatible software versions.
  • Review Software Configuration: Verify that the software configuration is correct for the mixed mode operation of 2G and 3G.
  • Apply Software Patches: Install any available software patches or updates that address synchronization or 2G-related issues.