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Abis configuration for EDGE

Viewing 15 posts - 1 through 15 (of 24 total)
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  • #66419
    OMAR
    Guest

    PLEASE CAN YOU TEL ME IF THE FOLOWING CONFIGURATION IS GOOD

    IN ERICSSON for on cell:
    WE HAVE 6 TRX WITH CONCENTRATED SIGNALING and WE HAVE 11 TS FOR SPEECH (16K) and 4 TS for EDGE ( RES64K).
    also we have the cell with Numreqegprs=4

    #66420
    SHELDON
    Guest

    Hi Omar,

    If the configuration is good, then you should not have any alarm( INSUFFICIENT EGPRS EQUIPMENT if you do RXCDP or ABIS PATH UNAVAIL when you do RXASP).

    The abis resources are shared among all the cells on a site, so if you don’t provide the information about the other cells, it will be impossible to judge whether the configuration is correct or not.

    Regards,
    SHELDON

    #66421
    OMAR
    Guest

    THE SITE HAVE ONE CELL WITH 6 TRX

    #66422
    SHELDON
    Guest

    In that case, your configuration should be good, but verify with RXCDP and RXASP. If everything is alright, then there should be no alarm, as I mentioned in my previous post.

    If you want a detailed calculation of the required abis capacity, pls provide the CONFACTOR and the number of SDCCH/8s in the cell.

    Regards,
    SHELDON

    #66423
    Optim
    Guest

    Hello Sheldon,

    ” INSUFFICIENT EGPRS EQUIPMENT ”
    Please confirm this alarm comes up when there is no free TS in allocated E1 for the site?

    Suppose we have 6/6/6 site config with 3 SDs in each cell and confact is 2. What’s going to be the suitable config. in terms of E1s?

    Thanks,

    #66424
    SHELDON
    Guest

    Hi Optim,

    “INSUFFICIENT EGPRS EQUIPMENT” will pop up when one or both of the following are true:
    1. You have not defined the required number of abis timeslots
    2. You have not opened the required DCP2s (8 on the EDGE TRX).

    Here’s the calculation for your 6/6/6/ site.

    i) Total number of radio TRXs = 18
    ii)Total number of timeslots = 18*8 = 144

    iii) Total Number of TCHs = 144 – 9(3SDs per sector *3) -3(BCCHs)= 132

    iv) Total Number of Abis timeslots required for voice (TCHs) = 132*1/4 = 33 (remember each TCH requires 16kbps on the abis, which is 1/4 of the abis timeslot).

    v) Total Number of abis timeslots for signalling = 18/2 =9 (18 being the total number of TRXs, 2 being your CONFACTOR).

    Number of abis timeslots: Not given

    TOTAL NUMBER OF ABIS TIMESLOTS NEEDED = 33+9 = 42.

    Remember, however, that this excludes the number of EDGE timeslots, which you did not provide.

    Regards

    #66425
    OMAR
    Guest

    NORMALY THE SD AND THE BCCH NEED A RESSOURCE IN THE ABIS

    #66426
    Optim
    Guest

    Thanks Sheldon,

    Precisely explained by you. We are using 4 edge TSs mostly, so if we add 4 edge TSs here in your calculation, what it would result then?

    Four EDGE TSs means Four ABIS TSs ?

    Thanks,

    Optim

    #66427
    SHELDON
    Guest

    Hi Optim,
    Four EDGE timeslots per cell gives a total of 12 extra abis timeslots.

    But then you will have to subtract 12 from iii), before you find the abis capacity for the voice.

    Total Number of TCHs =132-12 = 120

    Total number of Abis timeslots for voice =120*1/4 = 30

    Therefore, total Number of Abis timeslot needed for the site = 30+9+12 = 51

    @Omar,
    No, the BCCH and SDCCH don’t need a separate resource on the abis. They form part of the signalling, which I included in the calculation.

    #66428
    OMAR
    Guest

    HI SHELDON

    CAN YOUR GIVE ANY INFORMATION FOR EDGE SINALING CONSIDERATION FOR ABIS CONFIGURATION

    #66429
    Optim
    Guest

    Sheldon,

    Spot on man, you clarified things really well.

    I need little more info. from you, which is, hoW one can see the no. of E1s a site has been configured with? I mean some fast procedure than RXAPP?

    Thank,

    Optim

    #66430
    SHELDON
    Guest

    Nope…RXAPP is the only one I know.

    Rgds

    #66431
    nj
    Guest

    Hi all,

    Our simple calculation of Abis TS is like:
    Abis TS= Total TRXs*2 + (Total TRXs)/CONFACT + Total EDGE TS(64k)

    For your ex:
    Total TRX= 6 * 3 =18
    confact =2
    EDGE TS=12
    Abis TS= (18*2)+(18/2)+12= 57

    So, at least you need 2 E1 (2*32)

    BR

    Nj

    #66432
    Optim
    Guest

    Hello Nj & Sheldon,

    there is a conflict between your calculations;

    What Sheldon has done, logically looks perfect, ‘each TCH requires 1/4 of ABIS TS’
    So with this in mind, total # of Abis TSs = 51 is perfect.

    While NJs formula is good and precise toOo, but it includes SDCCHs in the calculation hence requiring few more Abis TSs.

    Also as I heard that one 4/4/4 site requires exactly 1 E1, so based on this, NJ’s formula looks fine.

    PLease put some light on this both experts 🙂

    Thanks,

    #66433
    pix
    Guest

    hi,

    there is a major difference between NJ and Sheldon computations.
    NJ assumes that 1 TRX uses 2 full Abis TS (= 8 Abis nibbles).
    Sheldon assumes that 1 TRX uses only as many Abis nibbles as the number of TCH on that TRX. For examlple 1 TRX with 1 BCCH + 1 SDCCH + 6 TCH would use only 6 abis nibbles = 1.5 Abis timeslot.

    Both could be true, because it only depends on the E/// implementation.
    In ALU case, NJ would be right.
    In E/// case, I don’t know. Both are possible.

    regards
    pix

Viewing 15 posts - 1 through 15 (of 24 total)
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