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Erlang to kbps conversion

Viewing 10 posts - 1 through 10 (of 10 total)
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  • #35452
    Sunil
    Guest

    In the Erlang and VoIP Bandwidth Calculator, what is the significance of the Voice Paths option. Secondly I want to calculate the total kbps required for 1Erlang of Voice Traffic using a 8kbps Voice codec, 20msec Frame and blocking of 0.01%.What is the formaul to calculate?

    #35453
    Technical Support
    Guest

    Voice Paths are the number of voice channels available in the system.

    If you look in the Technical Papers area of this site, you should get some tips regarding your calculation.

    #35454
    veera hariandja
    Guest

    CMIIW

    voice codec = 8 kbps = 8000 bps
    TTI per frame = 20 msec = 0.02 sec
    duration of busy hour = 1 hour = 3600 sec

    1. Based on Table Erlang B, Voice path options for 1 Erl with blocking 0.01%, N = 7 path options

    2. Data erlang =
    (total number of frames transmitted * TTI per frame)/Duration of busy hour

    1 Erl = (x * 0.02)/3600
    x = total number of frames transmitted = 3600/0.02 = 180,000 frames

    y = total number of kbps transmitted = 180,000 * 8 kbps = 1440 Mbps

    #35455
    Bob
    Guest

    Hi Guys,
    very interesting topic,
    I am trying to calculate Erlang from NB interface to see how much POI Erlang is transited. but I got a bit confused please take a look
    Codec= AMR, Frame=Ethernet, BSC and POI are TDM base and NB over IP-
    12200*(20/1000) = 244 bits means–> 31 bytes —
    Ethernet =38, IP=20, UDP=8 , RTP=12 , NBUP=4 , VOICE=31 BYTES Total Bytes for AMR=117–> 117*8*50=45.2kbps- Number of ephemeral channel = Occupied BW/45.2kbps now if we consider the occupied BW is 90.4Mbps then number of ch=20k my concern is this, how do I obtain Erlang from it?
    Thanks in advance

    #35456
    Bob
    Guest

    I found answer to my own Q:
    Bandwidth estimation for a connection using compressed speech can be calculated by Activity Factor (AF) as follow
    BW=AF×bitrate(Speech)+(1-AF)×bitrate(Silence)
    Where
    BW=Bandwidth on L2 Layer
    AF=Percentage of Activity Factor–>(1-AF) =Percentage of Silence
    Bitrate
    On Ethernet Link Layer:
    Bitrate=(payload Size + IP header + Ethernet Framing) × Tx Rate
    On IP Backbone (MPLS) Link Layer:
    Bitrate= (payload Size+ IP Header + L2 Overhead) × Tx Rate
    Where
    TX Rate= Transmission Rate/ Packetization
    Ex: A Speech Call on NB with AF=60% and using AMR 12,2 mode consume a following bandwidth (Ethernet + VLAN)
    BW=(60*46.8kbps+(100-60)*4.6kbps)/100=29.9kbps
    where
    bitrate(Speech)= (35+40+42 bytes)* 50/s=46.8kbps
    bitrate(Speech)= (9+40+42 bytes)* 6.25/s=4.6kbps
    Now if occupied BW=46,8M then Virtual Channels = 46,8m/46.8=1000
    For Calculating Erl we need number of channels and GOS- so very easy Carried Erlang is obtained–>ErlangTraffic(N,GOS) where GOS=.001

    #35457
    prabhu
    Guest

    how to convert erlang to bitrate on Iu interface.actually Iu-PS interface

    #35458
    Ommah
    Guest

    In order to covert a traffic in Erlang to Mbits, you can use the below:

    First of all, you have to convert your traffic from Erlang to Minutes@Busyhour. This can be done by multiplying the traffic in Erlang by 60.

    You have two types of services with a traffic in Erlang: CS voice and CS video

    For the voice:
    (Traffic_Minutes@Busyhour x 60 x EBR) / (3600 x 1000) = xxx Mbit/s@BusyHour

    Where EBR is the Equivalent Bit Rate for the service.

    #35459
    Usama
    Guest

    I have total Erlangs for GPRS/EDGE traffic for a network…How can i calculate the equivalent Mb traffic for this data traffic.

    #35460
    aseem
    Guest

    I know Voice MoU per subscriber in a circle – how do I CONVER this to data in mbps or kpbs?

    I am trying to find out how much data can one BTS handle , and how many subscriber 1 BTS can handle both voice and data?

    I want to predict number of small cell solutions that can be deployed in a densily populated area?

    #35461
    MG
    Guest

    CMIIW

    voice codec = 8 kbps = 8000 bps
    TTI per frame = 20 msec = 0.02 sec
    duration of busy hour = 1 hour = 3600 sec

    1. Based on Table Erlang B, Voice path options for 1 Erl with blocking 0.01%, N = 7 path options

    2. Data erlang =
    (total number of frames transmitted * TTI per frame)/Duration of busy hour

    1 Erl = (x * 0.02)/3600
    x = total number of frames transmitted = 3600/0.02 = 180,000 frames

    y = total number of kbps transmitted = 180,000 * 8 kbps = 1440 Mbps

    y = total number of kbps transmitted = 180,000 * 8 kbps = 14,400 Mbps et non 14400 Mbps
    X=180000
    Y=180000 * 64 kbps = 11,52 Mbps
    64 & gos 0,01 y= 23, 040000
    Y=28,8 si gos = 0,01 et voice =8 .

Viewing 10 posts - 1 through 10 (of 10 total)
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