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hieuphong
2014-05-28, 12:26 AM
Dear all!
I'm working with E******* devices:p. I want to reduce Call drop rate and handover failure. Please tell me what parametter I need to change and explain why?

juanpico
2014-05-28, 10:03 AM
Hi Hieu.phong
Before changing any parameter, have you tried reviewing all neighbor relations? Most CDR and HO failure is cause by lack of immediate neighbor.
Dear all!
I'm working with E******* devices:p. I want to reduce Call drop rate and handover failure. Please tell me what parametter I need to change and explain why?

hieuphong
2014-05-28, 12:54 PM
Hi Hieu.phong
Before changing any parameter, have you tried reviewing all neighbor relations? Most CDR and HO failure is cause by lack of immediate neighbor.
Thank you so much! Do you have tool or macro to check BA list in GSM?

dtvt2
2014-05-28, 07:33 PM
something you can do
- Increase radio link time out
- Enable call reestablishment
- Change the threshold that used to evaluate Neighbor cell as candidate to HO

hieuphong
2014-05-28, 07:52 PM
something you can do
- Increase radio link time out
- Enable call reestablishment
- Change the threshold that used to evaluate Neighbor cell as candidate to HO
Dear dtvt2!
Anything else?
Reduce CDR i think Increase RLINK, ACCMIN, CRO
Reduce HO Failure I think Change KHYST or KOFFSET
But I don't know how to do. Can you tell me

rfworld
2014-05-28, 10:55 PM
Dear dtvt2!
Anything else?
Reduce CDR i think Increase RLINK, ACCMIN, CRO
Reduce HO Failure I think Change KHYST or KOFFSET
But I don't know how to do. Can you tell me

You have access to OMC-R? Take help from Alex.

fon909
2014-05-29, 01:58 PM
Hi,

Please try tuning L1, L2 and L3 timers to improve overall call drop rate. Also, please tell me under what category calls are dropping the most so that accordingly I will share other parameter tuning. Under handovers, is your SHO poor or IRAT?

hieuphong
2014-06-06, 11:52 AM
HOSR is so bad! I have checked neighbor and frequency but it's continuned. I don't know how to do. Can you tell me?

Optimustron
2014-06-06, 11:26 PM
Hi Hieuphong, I suggest to the following things thar maybe are redundant because some of them the people en this forum has told you before, but in order to tie up lose ends then I repeat that:


Check the causes of Drop Call, this is the principle of divide and conquer, that are the following causes, Excesive Timing Advance, Bad Quality, Low Signal, Suddenly lost connections, Others.
For the first one you can do the folowing things, if you have enough capacity you can use Extended Range if that is the last cell in the area, if not make down tilting and change ACCMIN and BSRXMIN/MSRXMIN.
For the second you need to check the frequency plan and look for interference if the first is ok.
For the third you need to increase power if you can and again change too ACCMIN and BSRXMIN/MSRXMIN, make down tilting, put TMA/MHA. But you need to check antennas too because they can be old, check RF path, i.e. feeders, jumpers and connectors too, if you have TMA/MHA you the to check if it's working ok.
For the forth you need to check if hardware is working ok, RF path, transmission slips, intermitence, etc. energy issues, etc.
For the others causes you need to check specially for example the behaviour of TRH, TRANSCODERS POOLS, some issues of transmission, like slips, timming, etc, energy issues, etc.
Please check external cell definitions and the related parameters specially RLDEP, RLLOP. Check too there is not cochannel HO's, large quantity of HO's then you need to review and eliminate the HO's with bad success rate if they are not indispensable.
Check definitions in CORE.


You need to do your homework with parameters, like ACCMIN and BSRXMIN/MSRXMIN, filtering SSLENSD/QLENSD/SSLENSI/QLENSI etc, you need to check the settings for and consistency of power control too like SSDESDL/SSDESDLAFR/SSDESDLAHR, /SSDESUL/SSDESULAFR/SSDESUAHR, QDESDL/QDESDLAFR/QDESDLAHR, QDESUL/QDESULAFR/QDESULAHR, you need check the filtering too, SSLENSD/QLENSD= 4 to 10 the lowest for zones with to much fading or highways too, the highest for residential zones with slow motion for example, SSLENSI/QLENSI= 3 to 5 this is for signalling for example a good value is 4 but in some places you can use 3 or maybe 2 in zones with fast traffic like highways, you need check too the DYNAMIC ALLOCATION and ADAPTATION too, the IDLE CHANNEL MEASUREMENTS and the intra cell HO settings in this case you can use the recommended values from E*******, by the way ACCMIN=MSRXMIN and you can adjust BSRXMIN=ACCMIN/MSRXMIN+OFFSET in order to make some little balance in UPLINK OFFSET can be from -5 to +5 for example of course you may use 0.

I hope this can help you, best regards friend,

fon909
2014-06-10, 11:07 PM
For bad Soft Handover, please identify missing neighbors, run WNCS, check the neighbors that are being attempted the most and are failing. Check if there is a SC collision, check if source/target is an overshooter through WMRR/ Propagation Delay reports. Check if neighbor is down (not radiating) and it is still being attempted (this is a case of zombie cells) in such situation delete the relations till the neighbor site comes up (is radiating). Identify the high failing relations using the counter pmNoTimesCellFailAddToActSet and perform above checks. Let me know if you require any further help.