- This topic has 2 replies, 1 voice, and was last updated 25 years, 5 months ago by
.
-
Posts
-
I have two questions. The first one is….Does anyone know what the probabilty of blocking is for the PSTN? I come from a mobile background where the goal is usually 2%.
Second. I have a design problem where I am allocating a fixed number of lines between two sites based on the amount of traffic between them. I need to determine what percentage of traffic is handled by lines 1 and 2 out of 5 total lines if it is assumed that if a call comes into an empty system it’s given to line 1 and if it comes into a non-empty system, it’s given to the lowest numbered link that is not busy. This involves using a Markov chain and the call arrival rate (.2) and call departure rate (n/5).
Thanks in advance.
I have to answer your first answer quickly for the moment, the GOS for PSTN is 0,01% so 1 out 100 calls blocked.
Regards.
With usual assumptions we can calculate your answers with Erlang B as follows with E being the erlang b function and a the offered traffic:
Traffic carried on first circuit = a(1 – E(1,a)) Traffic carried on second cct= a(E(1,a) – E(2,a)) Traffic carried on third cct = a(E(2,a) – E(3,a)) Traffic carried on fourth cct= a(E(3,a) – E(4,a)) Traffic carried on fifth cct = a(E(4,a) – E(5,a))
The pattern continues.
- The forum ‘Telecom Design’ is closed to new topics and replies.
