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7th May 2003 at 11:15 #35452SunilGuest
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?
7th May 2003 at 14:24 #35453Technical SupportGuestVoice 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.
22nd December 2010 at 06:50 #35454veera hariandjaGuestCMIIW
voice codec = 8 kbps = 8000 bps
TTI per frame = 20 msec = 0.02 sec
duration of busy hour = 1 hour = 3600 sec1. 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 hour1 Erl = (x * 0.02)/3600
x = total number of frames transmitted = 3600/0.02 = 180,000 framesy = total number of kbps transmitted = 180,000 * 8 kbps = 1440 Mbps
22nd December 2010 at 21:50 #35455BobGuestHi 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 advance26th December 2010 at 11:28 #35456BobGuestI 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=.0013rd April 2012 at 06:00 #35457prabhuGuesthow to convert erlang to bitrate on Iu interface.actually Iu-PS interface
19th November 2012 at 13:27 #35458OmmahGuestIn 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@BusyHourWhere EBR is the Equivalent Bit Rate for the service.
25th July 2013 at 06:34 #35459UsamaGuestI have total Erlangs for GPRS/EDGE traffic for a network…How can i calculate the equivalent Mb traffic for this data traffic.
26th September 2013 at 13:20 #35460aseemGuestI 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?
26th February 2015 at 18:32 #35461MGGuestCMIIW
voice codec = 8 kbps = 8000 bps
TTI per frame = 20 msec = 0.02 sec
duration of busy hour = 1 hour = 3600 sec1. 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 hour1 Erl = (x * 0.02)/3600
x = total number of frames transmitted = 3600/0.02 = 180,000 framesy = 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 . -
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