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Erlang to minute conversion

  • This topic has 23 replies, 1 voice, and was last updated 2 years, 4 months ago by Erlang(TCH) to coast conversion.
Viewing 15 posts - 1 through 15 (of 24 total)
  • Author
    Posts
  • #49784
    Latheef
    Guest

    If a route which have 20 circuits carried 3.3 Erlangs in one hour.
    How do i convert 3.3 Erlangs to minutes.?

    #49785
    pix
    Guest

    3.3 erlangs = 3.3 hours of cumulated time of traffic onto the system

    3 hours = 180 minutes
    0.3 hour = 20 minutes

    3.3 hours = 200 minutes

    #49786
    latheef
    Guest

    thanks pix…

    any specific formula to do this Erlnag to minute calculation.

    If the hourly traffic has been read are you saying the traffice carrried on that particular is an accumulated figue?

    Thanks

    #49787
    pix
    Guest

    the erlang is the cumulated time of traffic carried in the channels of the observed system.

    1 erlang = 60 minutes
    2 erlang = 120 minutes
    3 erlangs = 180 minutes
    4 erlangs = 240 minutes
    40 erlangs = 2,400 minutes
    400 erlangs= 24,000 minutes

    and so on… there is no formula.

    you measure 3 erlangs between 9am and 10am, it meands that there were 180 minutes of usage of your system at that hour.

    #49788
    Arun
    Guest

    Dear Pix,

    Does that one hour include the unsuccessful calls also or is the erlang calculated only for successful calls.

    regds
    Arun

    #49789
    pix
    Guest

    erlang is the amount of traffic really carried ! does an unsuccessful call put traffic on a carrier ?
    – yes, on a SDCCH –> therefore unsuccesfull call increases the amount of SDCCH erlangs.

    – no, not on TCH –> therefore the TCH erlangs are not impacted by unsuccesful calls.

    #49790
    Arun
    Guest

    Dear PIX,

    Thx for clarifying the doubt.

    regards
    Arun

    #49791
    scor
    Guest

    Hello Mr.Pix,

    IM into OMC Side.

    What is the ratio between the TCH Erlangs & SDCCH Erlangs . Ideally the SDCCH Erlangs should be on the higher side. right

    And the TCH Erlangs does capture the missed calls

    Thanks

    #49792
    pix
    Guest

    scor,

    sdcch traffic is about 10 times smaller than tch traffic (approx.)

    unsuccessful calls (mean there was a failure during the call setup) do not use a TCH carrier. The failure occurs while they are on the sdcch channel. therefore they simply cannot be counted in the tch traffic.

    if the failure occurs after the callsetup, then it is called a call drop. A call which is dropped occupies a tch carrier for a while, therefore it is counted in the tch erlang.

    #49793
    scor
    Guest

    Mr.Pix,

    Is the same calculation holds good when we apply half rate erlang also.

    Thanks

    #49794
    pix
    Guest

    scor,

    of course 🙂 if you activate HR at 60% traffic load on a cell with 30 TS, the actual number of carriers in your cell is :
    (60% of 30) + (40% of 30)*2
    = 20 + 10*2 = 40 carriers

    you can compute your capacity based on this input.

    Pix

    #49795
    Cplus
    Guest

    I would like to ask you a question.. I hope there is someone is able to help me thanks. .the question is :
    Why do we use Erlang B tables and explain the reason of the 10 times more bandwidth than the average traffic..

    thanks in advance…

    #49796
    Pix
    Guest

    Bandwidth ?

    I assume you mean the number of channels compared to the number of erlangs?
    6 channels can carry only 2.3 erlangs (which means that only 2.3 channels are busy during one hour, in average, but that’s enough to get 2% congestion), and so on?

    Well, the reason is because the traffic has a random rate of arrivals, and you want to keep the probability of “1 call incoming while 6 are already engaged” as low as possible (below 2%).

    Regards,
    Pix

    #49797
    cplus
    Guest

    Dear Pix, is that last answer for my question ? Because i have doubt whether is for my question or not. Thank u very much…

    #49798
    pix
    Guest

    … yes, that was for you, Cplus.
    I’m afraid my answer does not answer your question???

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