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Poor Handover Success Rate—Pix

  • This topic has 18 replies, 1 voice, and was last updated 10 years ago by Brian.
Viewing 15 posts - 1 through 15 (of 19 total)
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  • #63836
    Suzane
    Guest

    Hi,

    I am having ALU Network & HOSR is very poor, Only 50% of cells are above 95% of HOSR. Done phys. optimization & Intra cell Enabled. HO Margin Qual as 1 & HO Margin Lev as 2, Candidate cell priority as 0.
    Can you suggest to improve HOSR with some other paraset???
    Is there any DTX related parameter which can help??

    #63837
    ALU
    Guest

    Hi Suzane,
    Even though this query was intended for Pix but I m sure both of u wouldn’t mind if I share my views aswell ๐Ÿ˜›
    50% of cells below 95% HSR is a huge number…are most of the cells in your network Remote or Urban?
    Secondly, you should keep into consideration the fact that you are talking about Handover Success Rate and not Efficiency Rate. So, congestion can be a reason for that.Do check it!
    Also, per neighbour parameter tuning is also very important and helps in improving HSR for cells.Check whether the problem is occurring with one or two neighbours or majority of neighbours. If its with majority, you can suspect hardware problem(suma etc).If with one or two neighbours, you need to investigate whether there it.Check possibilty of BCCH Clash and even Co BCCH-BSIC case can be catastrophic for a cell. Also you can harden a handover to the cells with which you are having degraded HSR and ease out handovers to the cells which are having good HSR and high no of attemtps aswell.

    As far as DTX is concerned, even though its not advisable to use DTX with AMR in Alcatel….but we enabled DTX with AMR in our Network and considerable reduction in Quality Handover Percentage and Increase in HSR is observed in the Network.Having said that, its still risky because I have witnessed myself the exact opposite of that(increase in Quality handovers after enabling DTX+AMR) in the previous network that i was working on.So, i would suggest that you first implement it in a small scale and if its giving good results, you generalize it.
    Regards

    #63838
    pix
    Guest

    What more can I add ? It’s all there.

    Oh yeah, ALU forgot to talk about the weather, so here i go : rain.

    #63839
    Suzane
    Guest

    Hey Pix & ALU,
    Thanks for your reply,
    1. There is no Co-BCCH & BSIC as we gone through Optimi AFP.
    2. The cells less than95 are in both category urban & rural(some are low call volume)Is there any Parameter to avoid Handover if low call.
    3.What is SUMA?
    4.How can i harden the handover?
    5.DTX with AMR in B10,are there any issues..??
    6. Can you suggest some general Parameters which i can fine tune for HOSR improvement?

    #63840
    ALU
    Guest

    Dear Suzanne,

    1. Good.

    2. No there is no parameter as such.

    3.SUMA is the processing card(brain) of the site.

    4.You can harden a handover to another cell by playing with the HO_Margins(lev,qual etc) or even linkfactor.Also remember that u can always play with Rxlev_min(n) to prevent handover to target cell unless the level served by target cell is better than this threshold.

    5.I already answered this question ๐Ÿ™‚

    6. I would like to take Pix’s views on this.As far as i m concerned,there is no such thing as a general “magic parameter” that will resolve all of ur issues.Optimization Actions vary from case to case ๐Ÿ™‚

    P.S(@ Pix): I have worked on NSN(ex-Siemens) aswell and they have the parameter Rxlevmin on adjacency level unlike Alcatel where its cell level.This is very useful if present on adjacency level.Any reason why Alcatel is not providing this on adjacency level?Wat are ur views abt this?

    #63841
    Mania
    Guest

    Hi Suzanne,
    just to jump into the discussion.
    Do check your SUMA configuration of the network if its running on free running clock. try changing it to GPS synchronized (i think it required some hardware) or atleast to PCM sync, the normally is one thing that can severely effect HSR, esp if you have fluctuations in the region.
    DO check your SUMA sync mode and inform.

    #63842
    Pix
    Guest

    Alu

    the rxlevmin per adjacency can be Simulated by other adj parameters such as link factor. There are so many params already in alu, it s difficult to want more ๐Ÿ™‚

    #63843
    suresh
    Guest

    Hi pix,

    how we can play with rxacc min for adjacency for handover? can u plz explain with some example?

    #63844
    pix
    Guest

    suresh,

    you mean : in alu system ? there is no rxacc per adjacency, in alu.

    #63845
    suresh
    Guest

    Hi pix,

    buddy i want to understand how accmin will help in adjacency for handover? plz help…..

    #63846
    Sowjanya
    Guest

    Hi , can anyone say how to improve o/g handover success rate.What are the parameters to be checked.

    #63847
    Amit Kumar Srivastava
    Guest

    Hi , can anyone say how to improve o/g handover success rate.What are the parameters to be checked.

    #63848
    Brian
    Guest

    Hi,

    I am new into alcatel system and am having the same HOSR problems. For example, one site of the worst has a SUMA which indicates a yellow colour, i querry for the alarms but it doesnt show any.

    I dont have the right to change parameters but i do tell the responsible person what to change. Yet in this case i dont know what to change. The HOSR for this site is below 50% and there is no congestion to it. What can be done to resolve the issue?

    #63849
    pix
    Guest

    hi brian,

    how many attempts per day ? (to ensure that the 50% HOSR is relevant)

    I would assume there is :
    Either, a coBCCH coBSIC in the vicinity.
    Or, a clock issue in the SUM.

    For the clock issue, you have to find an OSS engineer to check SUM alarms, or ask to replace the SUMA on the field.

    Basically, you can only do 2 thigs :
    1/ find which relations are faulty, and check the bcch/bsic usage on the map
    2/ test a change of BSIC
    3/ ask to troubleshoot the SUMA Clock. Ensure the SUMA synchronisation configuration is correct.

    Regards,
    pix

    Regards,

    #63850
    Brian
    Guest

    Hi Pix,

    I querred for the alarm attached to suma, and this is what i get:
    1. Probable Cause: X721-equipment Malfunction
    2. Specific problems: 150383 CLK[1] HW-Degraded[237]

    What can we conclude from here,

    FYA: look at the HOSR data below for the cell in discussion.The data is on daily basis

    Malembo_2 18.03% 12.33% 13.52% 22.04% 18.86% 21.43% 17.35%

Viewing 15 posts - 1 through 15 (of 19 total)
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