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Viewing 6 posts - 1 through 6 (of 6 total)
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  • #45694

    Hi all,
    I’m working on Alcatel equipement, please anyone can explain to me :
    – the principle of the RACH TA FILTER,
    – In which cases we can activate this filter,
    – What’s its impact on the quality parameters (TCH & SD congest,..)
    Thanks a lot


    hi everybody.
    any body can explain the role of spilleter in the BTS and how much power it cosumed and what its name in the nokia bts.thaku


    hello lofti,

    the rach ta filter is a value (distance, in steps of 500m) will prevent the mobiles located further away than a certain distance from the BTS.

    By default it is defined to 63 (max. distance), all mobile within a radius of 32km will be accepted in the cell. Accepted = they can camp in idle mode, receive and send calls, etc.

    You can decide to reduce the distance in certain cases, if the cell is resurging, or if it creates somehow a conflict with other cells. Well, many cases are available. For instance, you might want to limit the rach ta filter to 1 for micro cells, so they don’t catch mobiles that are located more than 500m away.

    Good luck,


    Hi aman

    Splitter is a passive device becaus thsplitter did’t consume power , The spliter used to sharing the recive signal to the TRXs . In NOKIA BTS Splitter is calld ( Multicuppler )


    but a splitter does take a toll of few decibels though..


    RACH filter – in a mature network there is a tight co-channels re-use.With this filter you can try to filter out rachs witch ms sended to others co-channels bts. This way in theory you can reduce sdcch assignment failure.(when bts allocate sdcch but nobody ask for it in this cell)
    but in practic if real mobile trying to get to bts but you filter out it rach with filter (wrong setting) ms can stay without service until cell reselection(if possible)
    MOC case – user have to call twice to reach the network
    MTC case – ms can be not reachable from the first attempt.(depends from the number of paging and time between paging) Remember this.

    2 way spliter – 3db loss

Viewing 6 posts - 1 through 6 (of 6 total)
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