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Traffic balancing

Viewing 12 posts - 1 through 12 (of 12 total)
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  • #59175 Reply
    Amo
    Guest

    We have some cells having almost congestion. But the DCS layer is not loaded high, around 60%.

    I read there are methods like traffic HO, DR, cell reselection.

    Which is best to make traffic balance between cells?

    I tried to make balance with HO(alcatel: DELTA_HO_MARGIN, preferred band HO, Multi band PBGT HO, High load, Low load).

    Somehow I send traffic to other cell, but in result DCS cell is congested and GSM is half loaded.

    What methods do you use for balancing traffic?

    #59176 Reply
    Pix
    Guest

    hi Amo,

    it is a very very very complex optimization.
    Between these two cells, use the preferred band HO from 900 to 1800, and disable (or slow down) pbgt HO frfrom 1800 to 900.

    in 900
    EN PREFERRED BAND HO = enable
    MULTIBAND TRAFFIC CONDITION = any
    L RXLEV CPT HO(900,1800) = -75dBm

    in 1800
    EN MULTIBAND PBGT HO = disable
    ****or…
    HO MARGIN (1800, 900) = +20dB
    EN_TRAFFIC_HO(1800, 900) and (900,1800) = disable****
    HIGH TRAFFIC LOAD = 85%
    A TRAFFIC LOAD a bit less than default

    Then you fine tune the L RXLEV CPT HO(900,1800) = -75dBm
    -73dBm to reduce load in 1800
    -77dBm to increase load in 1800

    Also, check that Cell reselect offest of 1800 is not too high (CRO = 4dB or 6dB is enough, usually)
    Cheers,
    pix

    #59177 Reply
    Amo
    Guest

    Hi PIX,

    Thanks for info. Can you explain me about Capture HO? I’ve enabled it on some cells and we got bunch of unnecessary HOs. From drive test I could see everything perfect in A cell but after, let’s say 4sec, there was HO to B cell which is worse than A cause I was near A. And from B there was HO to A, I guest PBGT HO. And again after 4sec HO to B or another. I didn’t understand.
    Also I thought whatever value on Multiband traffic condition parameter, it’s valid only after Capture HO is enable right ?

    Also A Traffic HO is averaging window right? Isn’t it bit dangerous to change averaging window?

    Anyway, sometimes I could manage traffic between some cells pretty well and sometimes it’s totally useless. And I end up with conclusion of “it’s dependent on traffic pattern, user behavior”.

    #59178 Reply
    Pix
    Guest

    Amo,

    Capture HO = general Capture HO ? You should always disable it !
    Just enable the Preferred band HO, which is based on similar “capture” behaviour, but much more easier to tune.

    The optimization of multiband network is really complex, you need to know perfectly all algorithms and parameters ๐Ÿ™‚ ALU provides these kind of trainings, if you are interested, let me know…

    Tuning averaging window is not dangerous ๐Ÿ™‚ But you need to know what it is and why you’re doing it. I gave you the right values for all parameters… either you apply 100% of them, or none, but don’t do anything else on top of it. General Capture is a bad idea… And yes, you are right, you must manage the PBGT HO in the other direction. The values I gave you are taking this into account already.

    Cheers,
    Pix

    #59179 Reply
    Amo
    Guest

    Thanks Pix,

    Well, I got some training from Alcatel. But when I was there, RNO was totally new for me. Now if I can have this training again I would ask much more effective questions.

    Pix,
    I wonder, you disabled traffic HO between bands and then you changed parameters that are used for traffic HO. How’s that so ?

    #59180 Reply
    Pix
    Guest

    Amo,

    When did you have this training ? Maybe we have met ?

    But there are other trainings, such as Multiband multilayer optimization… 5 days of intense brain melting…

    I said
    1. Disable Multiband PBGT
    OR
    2. change HO margin + disable traffic HO

    It is a “OR” not “AND” ๐Ÿ™‚

    Cheers,
    Pix

    #59181 Reply
    Amo
    Guest

    Hi Pix,

    I got this training in 2007 in Timisoara, Romania. You have pretty cool experience which will help us(guys in forum) a lot.

    I’m referring to below line.

    EN_TRAFFIC_HO(1800, 900) and (900,1800) = disable****
    HIGH TRAFFIC LOAD = 85%
    A TRAFFIC LOAD a bit less than default

    BR,
    Amo

    #59182 Reply
    Pix
    Guest

    Amo,

    Oh, so we didn’t meet (yet !) Please keep in mind that other trainings will probably be very beneficial for you. Looking at your questions, you are probably ready for them ๐Ÿ™‚

    EN_TRAFFIC_HO(1800, 900) and (900,1800) = disable****
    –> Disable cause 23 “traffic ho”

    HIGH TRAFFIC LOAD = 85%
    –> cell 1800 is “high loaded” only if tch load > 85%. It is used in several algorithms, including HO cause “traffic ho”, but also HO cause “preferred band ho”.

    A TRAFFIC LOAD a bit less than default
    –> used to detect & compute the “high traffic load” state.

    #59183 Reply
    Amo
    Guest

    Hi Pix,

    Can you send me the training list(catalog) for 2010(2G and 3G)?

    I read from document that DR is a good solution for traffic balance. Balancing with HO will lead to high rate of HO per call while DR will not. Do you have parameter suggestions on DR between bands?

    #59184 Reply
    Pix
    Guest

    Amo,

    I can send it to you but I don’t have your email. I can give you the webpage where you can contact our “contact center” (tomorrow…)

    regarding DR, it is simple : enable EVERYWHERE !

    FDR on the other hand is quite complex to manage between bands because you must set priorities per adjacencies. But you can simply enable it in the 1800 cells, in order to off load them to 900 cells. And don’t forget to disable FDR in 900 cells.
    EN FDR (900) = DISABLE
    EN FDR (1800) = ENABLE
    RXLEV NCELL DR (900) = -80dBm
    RXLEV NCELL DR (1800) = -47dBm ( = can’t be chosen as target cell)
    FREELEVEL DR (900) = 1 or 2 or 3 …

    The flow of FDR will go from congested 1800 cells to 900 cells only ๐Ÿ™‚
    cheers,
    pix

    #59185 Reply
    Amo
    Guest

    Hi Pix,

    I’ll try these and let you know the result.

    Meanwhile, what do you think about cell reselection for traffic balance?

    We have here Ericsson BSS also and experts from ericsson making balance with cell reselection.

    #59186 Reply
    Pix
    Guest

    Yes, reselection is useful.

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