Inter MSC HO failures

[Processor]

Hello Friends,

Please i am having very high Inter MSC HO failures for two different BSCs and i have checked HO relations on the BSS and NSS which are all ok.

Kindly advise on what could be the likely cause of this.

Thanks

[miister76]

how about the synchronisation ?????

[maahsan]

Make sure all the remote LACs are defined properly in neghbouring MSCs.

[bobsh]

Hello Friends,

Please i am having very high Inter MSC HO failures for two different BSCs and i have checked HO relations on the BSS and NSS which are all ok.

Kindly advise on what could be the likely cause of this.

Thanks

Also you MSC handover failure is very high you need check corect or not BTS creation BSC and MSC , if NSN are ZEPO and ZEQO dump you need todo check!!!!! correctly created or not !

[Processor]

Vendor is ALU and all LACS are properly defined....and also the handover is from one RCP to another RCP belonging to the same MSC.

@ miister67....Please tell me more how synchronisation could affect handovers.

I need HELP!!!

[TechHW]

GSM :- Make before break,
All the handover processing and new channel assignment need to happen in timely fashion in sync with both the offices and channel release before new channel is completely assigned is handover failure/ drop.

[Processor]

But i'm having very high Handover_Return to Old channel(HO_ROC)....I have Agilent drive test logs....anyone who can help me here?

[zhanglw268]

Hello Friends,

Please i am having very high Inter MSC HO failures for two different BSCs and i have checked HO relations on the BSS and NSS which are all ok.

Kindly advise on what could be the likely cause of this.

Thanks
Do you mean intra-MSC inter-BSC handover?
1. Check to see whether the handover failure is one directional or both way?
2. Check 2 BSCs' A5 ciphering setting, they shall use same ciphering, if they have different A5 settings, please make MSC's "HANDOVER COMMAND" with "Cipher Option" in it as mandatory.
3. Check the "Voice version" for Full Rate and Half rate between 2 BSCs during the MSC handover message, make sure that they are supported.
4. Check whether A interface HO_REQUEST "Address Indicator" is difference between 2 BSCs
5.Check whether the HO Number etc. format is inter-operational each other.
6. Check whether MSC's CGI and module ID in "Cell Description Table" are different from those in "Cell Module Information Table".
7. Check to see whether CGI, BCCH and BSIC in "External Cell Description Table" are different from those in the opposite BSC.
8. check whether the DPC of BSC in MSC "LAI And GCI Table" is incorrect
"HO-REQUIRED" will not be sent to target BSC if the DPC is wrong at the MSC
9. Make sure that CGI of target cell is defined correctly at the MSC
10. Check the BTS E1's clock is sychronised with BSC

Hope that the above helps.

Zhanglw268

[kevin_h811]

Hi Zhang,

What id the meaning of DPC @ #8 of your statement.Thanks.

Regards//

[zhanglw268]

Hi kevin_h811,

DPC: SS7's Destination sigalling Point Code. It is the signalling point definition to route the call and message to the related BSC/MSC etc.

Zhanglw268

[mond86]

Same MSC but Different BSC/Different MSC and Different BSC

Check whether the Cell CGI on the BSC side is same with the CGI of MSC Side (LAC, NCC, BCC, CI)

Check for double entry of CGI but different cellname. Delete the other one but be sure to delete the fake one not the real one. It's up to you how will you check whose the real one.

Make sure that the cell has the correct neighbor defined to it.

List down those sites with poor HO, drivetest those site. Analyze your logfiles for any causes.. check you layer events to find out the source of the problem.

If it helps anyone don't forget to give thanks an reputation


thanks