hi,

I've got a question:
"5 Erlangs of load is offered to 15 circuits for half an hour followed by 15 Erlangs in the next half hour. Using the Erlang B formula(and thereby assuming equilibrium conditions in each half hour slot) calculate the blocking probabilities in each half hour. Assume that the mean call holding time is 3 minutes. Use these values to estimate the probability that a randomly chosen call in the 1 hour period is blocked and compare this with the blocking when 10 Erlangs is offered to 15 circuits."

the B-formula is ((a^N)/N!)/(sum over i from 0 to N of (a^i)/i!)
where a(erlangs) = arrival / service rate,
N = capacity( is it equivalent to number of circuits?)
service rate = 1/3
and here's what i found:
a = 5, N = 15 => B(blocking probability) = 0.00015726
a = 15, N = 15 => B = 0.18032
a = 10, N = 15 => B = 0.036497
(can anyone check if i got these right?)

But how should I use these values and the mean holding time to estimate the probability and to compare these result with 10 erlangs 15 circuits?

Please help, i have to have it done by friday, thanks very much.

Pui

Pui, you have two replies to this in your follow uo post "Urgent...stochastic modelling(cont)". I hope that they have helped.