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## erlangb

version 1.0.0.0 (4.83 KB) by Colin Warwick

### Colin Warwick (view profile)

These are M-file examples related to the Erlang B formula for blocking probability.

Updated 02 Oct 2001

These are M-file examples related to the Erlang B formula for blocking probablity in telecommunications networks. They have been tested using MATLAB 5.3.1.29215a R11.1 but they are so simple they would probably work with any version.

### Cite As

Colin Warwick (2020). erlangb (https://www.mathworks.com/matlabcentral/fileexchange/192-erlangb), MATLAB Central File Exchange. Retrieved .

Eduardo Chancay

Eduardo Chancay

### Eduardo Chancay (view profile)

Why fn is erlangb(N, An)-B insted erlangb(N, An). Why you substract B?

ZHAO-JIE

### ZHAO-JIE (view profile)

Can this program work on the case if channel is robust(over 200)?

Nisar Ahmed

### Nisar Ahmed (view profile)

i inputed this code and it couldn't run, giving this error message "error in erlangb (line 7) b=erlang(n, a)" can some 1 help.

% ex1.m example for erlangb function
close all
clear all
lambda=0:0.0001:0.0065; % mean arrival rate (calls per second)
d=200; % mean duration (seconds per call)
a = lambda.*d; % traffic intensity in Erlangs
n = 1;
b = erlangb(n, a); % n channels/servers
ii=find(b<0.1);
plot(a(ii), b(ii), 'b')
hold on
n = 2;
b = erlangb(n, a); % n channels/servers
ii=find(b<0.1);
plot(a(ii), b(ii), 'g')
n = 3;
b = erlangb(n, a); % n channels/servers
plot(a, b, 'r')
n = 4;
b = erlangb(n, a); % n channels/servers
plot(a, b, 'k')
legend('1', '2', '3', '4 channels', 0)
xlabel('Traffic Intensity (Erlangs)');
ylabel('Blocking Probability');
title('Erlang B formula');
plot(a, 0.02, ':k') % 2% line

WilliamBernal

### WilliamBernal (view profile)

I was trying to understand the code because I am working in a code that let come with the same result as this paper:
ITU-R M.1768-1 called Methodology for calculation of spectrum requirement IMT. I have this report many times and other article trying to find out the equation and relation between the user density, session arrival rate, mean service bit rate, average session duration?

I read the code and the description, but this model only use the session arrival rate and he average session duration, Has anyone know how to calculate the spectrum capacity for switch circuit and switch package communication, or anyone know which equation use these: the user density, session arrival rate, mean service bit rate, average session duration to estimate the spectrum capacity?

thanks

Anurag Pujari

### Anurag Pujari (view profile)

Brian Borchers

This routine uses an oversimplistic algorithm that can fail in some cases. e.g.

>> erlangb(1000,900)

ans =

NaN

The correct value is 5.9-05

Helen Kim

A big fan :-)

##### MATLAB Release Compatibility
Created with R10
Compatible with any release
##### Platform Compatibility
Windows macOS Linux