Generic selectors
Exact matches only
Search in title
Search in content
Post Type Selectors

MC02d – ALU, help, please!

Viewing 8 posts - 16 through 23 (of 23 total)
  • Author
    Posts
  • #64991
    pix
    Guest

    denis,

    not at all ! i’m glad you shared your issue on this forum, because it is very interesting (to me…)

    cheers 🙂
    pix

    #64992
    Denis
    Guest

    thank for your support, mr.Pix

    i’m a persistent guy, but… kernel panic!!!

    to be continued… just on monday

    BR, Denis

    #64993
    p1988
    Guest

    Hello, Pix and Denis!

    I found many useful things in this discussion, but still don’t understand one moment:

    what does “follow on procedure” means?
    what will happen after normal message exchange (as for usual Loc Upd)?

    maybe you’ll be laughting ..
    but my task now is finding out the way to increase this counter MC02d in my network as much as possible…

    Do you have any ideas?

    :)))))

    #64994
    Pix
    Guest

    p1988,

    yes, you made me laugh !!!

    follow on procedure = the user is making a call while the MS is doing a Location Update.

    -> the SDCCH is used for LU, and then it is kep to establish the call (call setup procedure).
    One SDCCH is used by one MS : 1 LU + 1 Call setup, one after the other.

    This is very rare!

    This can happen if:
    1/ the MS is a device that never receives call and never perform LU. It only establishes call from time to time. So when establishing this call, it does a LU just before, to update the NW. (well, that’s the only example I could think of)
    2/ the user is very lucky… (too lucky to be true, though)

    After a normal location update, the SDCCH is released normally. Nothing special happens.

    MC02d counts the number of LU with follow-on request, is that true ? (I forgot)

    I don’t see how you could increase this counter… you just can’t force MS to do a LU just before a call. And you can’t certainly force your users to do a call while the MS is doing a LU. That’s insane.

    You should dig deeper in the 3GPP, see exactly what kind of scenarios they were thinking about (roaming ? emergency calls ? supp services ?). But anyway, I do’nt think you can increase it.

    Why do they want *you* to increase it? What’s their plan?

    Regards
    Pix

    #64995
    p1988
    Guest

    Hello, Pix!

    I’m glad to cheer you up :)))

    But I think you be laughing even more when you know the whole story. Where should I start?

    Maybe here – in our company in radio subsystem we use two vendors equipment: alcatel and huawei.
    And huawei is very aggressive, there are lots of its fans unfortunately. One of the argument in favor of huawei that it has better performance – i.e. better KPIs. Some of my colleagues had done the great job they figured out what was the thing. The problem was in methods of calculation it’s expected but they proved it. They also offered some ways to correct formulae – in order to have possibility compare comparable things. But nobody cares, all our standards are sent from headquarter and are like Bulls of Pope.
    But digging in counters and all that stuff they also found the other curious thing. There are many cells where CSSR is above 100% because Imm_Ass_Succ_Rate is above 100%.

    The formula we use Imm_ASS = (MC148 – MC02a)/ (MC01 + MC02 – MC964)

    And our guys found out that imm_Ass > 100% when MC02d is present and significant in the cell.
    After your explanation I understood at last what it means :))
    So increasing the MC02d will help to improve our kpis… that’s the matter

    Now – about really interesting stuff. I chose for my *research* 4 cells where mc02d is present permanently (i.e. every hour) and significant. Let’s take one of 4 cells – I studied it very well 🙂
    So we have:
    – mc02d is about 120-130 events per hour . even in the night!
    – At the same time the number of TCH normal assignments is much less: 30-40 per hour during the daytime and 3-7 in the night
    As you said *follow-on* means that MS initiating a call right after LU. So I think we should see that the number of TCH assignments must be equal or bigger than mc02d
    Did I understand you right?
    But it doesn’t happen. It seems that some MS (hm-m-m, not- some devices ) that is located at LAC boundary (for example) is performing LU very very often (mc02d per hour). But they are made in china and put bit FOR for *1* in CHNREQ message, not *0* like all other normal MS – it’s not my thought 🙂
    I’ve just citate my colleague 

    A GSM bedtime story :))))

    Regards,
    P1988

    #64996
    pix & its burning throat
    Guest

    hi !

    my last message was erased… booh.
    so here is a summary, I hope you don’t mind the short sentences… It’s because I’ve a bad headache and throat-ache:

    1/ if MC02d increases, your formula (MC148 – MC02a)/ (MC01 + MC02 – MC964) should DECREASE. Could you explain why it should increase ?

    2/ it’s great to see the technical teams doing the extra-work to prove that huawei is not so superior to other vendors. I hope your management will show some appreciation…
    Of course I would love to see your results : the formulas you suggest, the numerical comparisons, etc. If you feel like sharing, please send them to
    pix_erlang *at* yahoo *dot* com

    3/ the follow-on might lead to a TCH assignement, but it could also lead to sending a SMS or doing some supplementary services. Have you located in which 3GPP ref this is explained ? It might be a possibility that the follow-on leads to a TBF establishment – to be verified…-

    4/ can you trace one of those faulty MS, on Abis or A interface? Check what is the message that is sent after the LU is accepted. If there is no follow on, then the SDCCH is released. If there is a follow-on, then after LU Accept, you should see other messages on the SDCCH/RSL/N7 timeslots.

    I agree with you, it is probably faulty MS, but it’s good to find the proof. And the proof lies in the traces…

    Regards
    pix (the sick old man…)

    #64997
    p1988
    Guest

    Hello, Pix!
    Oh, it’s not good to have a throat-ache in such a hot summer
    I hope that you are better now, since your last post. In my country there is a medicine for such cases it’s called horseradish vodka 🙂 it is a medicine for real men 🙂
    But I hope you are recovered without such a therapy

    Back to GSM stories
    I’ll ask my boss to share that results about alcatel vs huawei comparison. I hope he won’t refuse me
    And I must say that I mislead you because the correct formula for Imm_Ass is

    Imm_Ass = (MC01 + MC02 – MC02a) / (MC148 + MC04 – MC 964)

    So called Immediate Assignment WITHOUT Loc Upd.
    As my colleague says in such way it could show values > 100%, if MC02d is significant. It should be substracted from the numerator because it also refers to LU and is taken into account by MC964.
    What a gap 🙂
    I’m not very confident with traces but my colleagues are, they also consider that it is the only way to find the answer So when we get some result I share it here

    I wish you the soonest recovery
    and thanks alot

    Good night
    Br, p1988

    #64998
    anuj
    Guest

    what is the normal value of mc02a counter in alcatel?

Viewing 8 posts - 16 through 23 (of 23 total)
  • The forum ‘Telecom Design’ is closed to new topics and replies.