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Umbrella Cell handover

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  • #46747


    I want to enable a umbrella cell HO for one site where we have Micro co-located with a Macro.

    Macro is taking a huge traffic but micro does not even take 1 erlang.

    Can anybody suggest me ,do i have to enable a umbrella cell HO in both the cells and also tell me how is it going to work and also what thresholds to set.


    Hello Nishant,

    Lucky you, i love multilayer network.

    If you have only collocated sites, i recommend you don’t create umbrellas.

    (remark : the parameters below are quite standard, but the names are not standard.. so you’ll have to translate them into your vendor’s language)

    So, try this :
    – activate a “CAPTURE HANDOVER” on the macro cell.

    – disable the POWER BUDGET HANDOVER on the micro cell.

    – Set the parameter “L RXLEV CPT HO(micro, macro)” = -77dBm (this parameter is the rxlev at which the macro traffic will be capture by micro cell)

    – Set the parameter “L RXLEV HO(micro)” = -85dBm (this will allow MS to exit the micro cell using “low rxlev on downlink” early enough to avoid a dropped call.. trust me, you have to use this way to exit the cell safely, since PBGT HO is disable)

    – Adjust downlink power control on the micro (U = -70dBm ; L = -80dBm) if it is enabled.

    Ok, good luck now 🙂



    Sure i will try this and let you know.

    pushpraj pachori

    working of surf in MOTOROLA bts


    hi pix,

    The option for capture handover is not there in Nokia .

    If you know the commands can you tell me.


    hi nishant, sorry i don’t know which command… but i’m CERTAIN there is a type of handover that acts like a “capture ho”. Try to find it…

    Ok, let’s see.. what you could do : list down all the cases of Handovers in Nokia system.

    1 due to low RXLEV in DL
    2 due to low RXLEV in UL
    3 due to poor RXQUAL in DL
    4 due to poor RXQUAL in UL
    5a due to too short timing advance
    5b due to too far timing advance
    6 due to POWER BUDGET
    7 due to high level of interference in UL
    8 due to high level of interference in DL
    9 umbrella / upper layer cell -> lower layer cell
    10 900 cell -> 1800 cell
    11a inner zone / outer zone
    11b outer zone / inner zone
    12a AMR HR -> FR
    12b AMR FR -> HR

    … what else ??
    for instance, cause 9 and 10 are kind of identical to a “capture ho”.

    parminder singh

    Can anybody tell me how to improve RX Qual in Motorola.


    Hello Pix,

    This is the first time we want to implement Upper/Lower layer in Our network (Alcatel vendor) :
    Upper Layer : 900 BTS
    Lower Layer : 1800 BTS

    If i understand well your recommandations, sectors of the 900 band would be declare as SINGLE cells instead of Umbrella, and then sectors from 1800 bands as Micro cells ?

    What others parameters should I tune apart of CAPTURE HO and disabling POWER BUDGET HO?

    Thanks in Advance



    When you work with 900/1800 network, you should make a decision :
    which handover cause will you use to push traffic from 900 to 1800 cells ?
    – cause 14 : umbrella to mini cells
    – cause 21 : 900 cells to 1800 cells.

    I recommend the cause 21 if you didn’t attend to the specific alcatel training about multiband management.

    cell type = Single for all cells
    **in GSM900 cells:
    RXLEV_ACCESS_MIN = -104dBm
    EN_PREFERRED_BAND = enable
    L_RXLEV_CPT_HO(900,1800) = -80dBm

    **in DCS1800 cells:
    EN_MULTIBAND_PBGT_HO = disable
    L_RXLEV_DL_H = -86dBm

    That’s a good start to balance traffic, quite simple to deal with. Other parameters don’t have any effect on this method.

    Beware that cause PBGT is forbidden from 1800 cells to 900 cells, and that the handover cause 5 (low level in DL) is the only way to exit a 1800 cell towards a 900 cell.
    PBGT HO is available between two 1800 cells, of course.



    Thanks Pix,

    I’ll give you a feedback as soon as we will implement this feature.


    Hi,we enabled Umbrella in 900 Nokia,but got problem 1800 high traffic.How we can stop Umb HO after 80% of loaded traffic on 1800?


    what switch name on Nokia is representing enable/disable Handover due to DL interference/UL interference?

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