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RACHBT in Handover ?

Viewing 8 posts - 1 through 8 (of 8 total)
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  • #49139
    Santo
    Guest

    Hi all,

    I want to know … is there any relationship between RACHBT setting and Handover Success rate ?

    Thanks

    #49140
    Tomar
    Guest

    Hi Santo,
    RACH busy threshold, defines a threshold for the signal level on the RACH. The general purpose of this parameter is to define a minimum level criterion a received RACH signal must fulfill to be regarded as a real RACH access.
    BTS continuously observes the signals received on the RACH slots. As even without any MS RACH access there are always at least some ‘noise’ signals on the RACH slots. The layer 1 subsystem is to evaluate the received signal with respect to specific criteria, e.g. it measures the receive level and checks if it exceeds defined minimum.
    The value entered for parameter RACHBT is not only relevant for the CHANNEL REQUEST message on the RACH but also for the HANDOVER ACCESS message on the FACCH! The level evaluation
    of RACHBT against the receive level of the handover access burst on the FACCH is exactly the same as for the RACH. Thus, the setting of RACHBT also has an influence on the handover success rate.
    From my experiences, value of RACHBT has big impact to the SDCCH Drop rate.
    BR
    Tomar

    #49141
    Sera
    Guest

    Hi Tomar,
    is there relationship between Rx lev Access Minimum and RACHBT setting in Call setup process ? Do we need to use both parameters on call setup process ? i’m little bit confuse about this matter..

    Thanks

    BR,
    Sera

    #49142
    aso
    Guest

    dear sera
    the RX lev Acce min is the parameter which affect after you initiate call ( affect path loss C1)and it value is different than RACHBT
    which it is very high than first one.

    #49143
    sera
    Guest

    Hi Tomar,
    Why is the value of RACHBT higher than RXLevel Access Minimum? Does it affect the success of Call Setup process? What about the value of RXLevel AMI higher than RACHBT? Can it happen in real network?

    #49144
    Tomar
    Guest

    Hi Sera,
    Try to read my article once more. The RXLEV Access Minimum is SysInfo broadcasted on BCCH. And mobile make decision, of received signal is for particular cell is above/below this threshold. The cell level is suitable or not for access. If the RXLEV is stronger than this defined threshold RXLEVACCMIN, than mobile could try to make Random Access on RACH channel. In the BTS is defined RACHBT. If the received RACH access (in the BTS) is below this threshold, than this random access is discarded.
    In Siemens is one counter, which counts number of discarded attempts. Set RACHBT according to BTS sensitivity. For proper settings of RACHBT, this counter could indicate wrong path balace.
    BR
    Tomar

    #49145
    sera
    Guest

    dear tomar,
    thanks for your kind information.. see u..

    #49146
    winb
    Guest

    hi tomar,
    i need to know the impact of the FACHBT on the handover,if it’s possible to give me the treshold

Viewing 8 posts - 1 through 8 (of 8 total)
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