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ALU: basic Abis nibbles

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  • #66891

    Hello, dear experts and gurus of Alcatel!

    I would be very grateful for your explanation in one question.

    In ALU’s docs i’ve found the following thing

    “Basic Abis nibbles are shareable at cell level”.

    So, does it means that i can use those Abis nibbles which are dedicated to another radioTS (maybe on the other trx) if those radioTSs are free now?
    I’ve become very intersted in this question because once in logfiles after drive-test i saw that i got a MCS-9 on the cell which have no extra Abis TS but has very low voice traffic and excess configuration (5 trxs)

    Am I right in my suggestion that it might be explained by using basic abis nibbles dedicated to another radioTS because they are free now?
    Maybe there are some indicators to check it?

    Thanks you very much!

    br, Sergio


    hi sergio,

    you are asking the right question, and your instinct is right too ๐Ÿ™‚ good job !

    Yes, the basic nibbles are actually “other” radio timeslots, which are unused.
    Those radio timeslots must however be inside the “PDCH limit zone”. I don’t know if you are familiar with this concept, but it’s very difficult to explain it simply. It is the amount of RTS in your Cell which is allocated to the MFS -> = all the RTS which “are” or “could be” used as PDCH.

    The size of this zone depends mostly on MAX PDCH and MAX PDCH HIGH LOAD parameters.

    Do you have access to any ALU document that explain this ? If not, are you working in a team that would be interested in a GPRS training ?



    hello, Pix!
    thanks alot for your explanation!

    just one more question:
    Is the parameter PDCH_limit_zone that you’ve mentioned connected with Max_SPDCH_limit that is reported from the BSC toMFS in RR Allocation message?
    if – yes than i think i understand what you mean… i hope because the thing is really complicated. but i read about it.

    you know i have too much docs ๐Ÿ™‚
    my fellow colleagues shared all they have. it’s since B8. so i’ve plunge into it and i might be drowned.

    i apologize in advance if my question are stupid ๐Ÿ™‚

    and unfortunately my company is not going to spend money for newcomers they think that elder colleagues have to share their experience and knowledge

    thank you, dear friend

    br, Sergio



    yes, the pdch limit zone is indeed controlled by the variable (it’s not a parameter) max_spdch_limit.

    if you have the docs, then you will be fine, eventually. Just take your time writing your own notes and your own examples.
    Your question wasn’t stupid, and if you’re willing to dig into this topic, then you yourself are certainly not stupid ! ๐Ÿ™‚ I will try to help.

    Even very experienced rf engineers in ALU are getting this part wrong sometimes…



    Good night time to everyone!
    Good night, Pix!

    Thank you for your kindly support and help! It’s indeed very noble of you.

    Digging in GPRS, I feel that i’m putting together a difficult puzzle… because i collect information on particles…

    i take advantage of your very kind offer to help and ask you a new question:

    nobody from my colleagues knows how to check throught OMC-R the Combiner (ANC) mode – combined or non-combined (low loss). this simple question happens to be very very important for us.
    the only way i have found untill now – is through HSDS Synthesis from RNUSM.The value in column MAX GMSK power shows us a MAX power of trx (in GMSK)- anc losses.
    But now i would like to export such data for whole OMC, but i don’t know how to do that. Please, help if you can

    thank you in advaneregards

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