- This topic has 17 replies, 1 voice, and was last updated 9 years, 9 months ago by taupaji.
14th June 2010 at 08:15 #63123KJBGuest
What may the reasons for HO drops.
How to improve by modifing parameters.
Suppose HO are being failed 100%,88%,89% with adjucent neighbours.Neighbour defined are bidirectional already verified.BCCH TRX QUality is also OK (89),Vendor is NOKIA.
KJB14th June 2010 at 09:46 #63124pixGuest
Such poor QoS is either due to :
1/ a terrible error in your frequency planning (same freq + same BSIC ?) (same frequency within the same BTS ?)
–> in this case, call drop, cssr and voice quality must be very bad too…?
2/ a software bug.
Now I am not familiar with nokia, so I cant tell you how to fix a sw bug. But you could try deleting the BTS from the OMCR and re-create it from scratch. That might clean the system.
pix14th June 2010 at 13:52 #63125KJBGuest
Neigbour Audit is done and all seems OK.
As far asa SW is concerned ,Same SW is working nationwide without any problem.
KJ14th June 2010 at 15:04 #63126PixGuest
Your logic is flawless 🙂
My car can’t have a flat tyre, otherwise all other cars would also have had a flat tyre.
pix14th June 2010 at 16:15 #63127BijoyGuest
Have you seen ND Report 204??
What is the reason for HO failure??
Have u checked neighbour definitions fron ZEAP;??
Bijoy15th June 2010 at 05:07 #63128ManiaGuest
Could you recreate the cell / problematic relation just to varify I have seen this to be helpful in some vendors (when all else fails). is HFR high for all adjacent neighbour or just one.. check its incoming is it bad with all then there might be hardware issue with that cell.
Also get a DT done and try to catch the issue is field try to isolate any specific codec / region / scenario that might be generating the failures.
@ Pix 🙂16th June 2010 at 08:46 #63129KJ BGuest
SW has been reinstalled before Flawless Statement:):):)
Neigbour relation is verified (BCCH,BASIC etc)with ZEAP.
ND report 153 show maximum HO failure with 3 site.
DL quality of BCCH TRXs is OK as per ND report 196 on Sourc and Target Cells.
I have used ND 154 in which maximum contribution is of Interference.
Maximun failure is in outgoing HO failure that is 66%.
Thanks for support.
KJ16th June 2010 at 11:29 #63130BijoyGuest
The trick given by Mania can work,actually it has worked many times.
If you want to drill down more,have you checked the slips on the E1?(ZYMO).
Also,you can put a trace for that particular cell to have a look at the failure messages.Maybe you will get a clue.
Bijoy16th June 2010 at 12:24 #63131KJ BGuest
Media is very stable,there are not any slips,es,ses using ZYMO.
Will Try Mania Trick:)16th June 2010 at 12:42 #63132PixGuest
I don’t want to goat but I said :
“you could try deleting the BTS from the OMCR and re-create it from scratch”
that’s what I meant by “sw bug”.
So the Mania’s trick should be renamed “Mania & Pix”‘s trick 🙂
pix16th June 2010 at 12:44 #63133KJBGuest
:):) OK Sir Mania & Pix Trick:))
KJ16th June 2010 at 17:36 #63134jackGuest
you said “you can put a trace for that particular cell to have a look at the failure messages”
my vendor is nokia.
how i can put a trace in cell in nokia BSC.
please explain for me step to step.
thanx17th June 2010 at 09:16 #63135kamal kotechaGuest
check 2745 Alarm in MSC,you will find the mis configured neighbours..You can check 2725 in BSC also..
204 Report will be useful too..18th June 2010 at 05:26 #63136BijoyGuest
In Nokia,a trace can be put on any cell of a BSC.
Regarding trace of TCH drop—TCH observation
SDCCH Drop-SDCCH Observation
All you need is to activate these counters
P.S. Only one cell per BSC can be put on any of these observation
Bijoy18th June 2010 at 06:10 #63137ManiaGuest
Thanks everyone for giving me the honour of naming a procedure after my name and using Pix and my name in the same sentence 🙂
and you can also check for synchronization issues with BTS.
These too result in Handover failures. how to check would be vendor dependent. for Alcatel the options of Sync_mode are GPS sync , PCM sync or free running clock… now if you have PCM synchronized and there are no slips then its ok or if its GPS sync and the signals are ok then too its ok. normally free running clocks can give you trouble.. In Alcatel SUMA ( the site processor) needs tweeking when this happens.
Synchronization can effect Outgoing handover or Inc_HO or both of a cell / multiple cells of same site.
If you find such parameter ‘Sunc_Mode” for Nokia do let us know for our information 🙂