Telecommunication also known as Telecom, is the exchange of all types of voice, data and video transmissions like signs, signals, messages, words, writings, images and sounds or information over significant distances by electronic means such as wire, radio, optical or electromagnetic systems.
It is a device which calculates number of telecom channels required to handle given telephone traffic using Extended Erlang B algorithm.
Erlang B formula
First, calculator uses Erlang B formula to calculate blocking calls fraction (call congestion) in telecommunication networks.
Where, A – offered traffic in erlangs
n – Number of communication channels.
This formula is not well suitable for computation systems, therefore, we use modified recursion formula:
Extended Erlang B
Traditional Erlang B model assumes that the caller gives up call attempts after blocking, but in real life some fraction of callers retry immediately. To take into account this nuance we increase traffic volume by the given fraction of blocked calls:
where– retries fraction.
Corrected offered trafficagain goes in Erlang B formula, which gives new blocking calls fraction. The process repeated until the stable value of corrected offered traffic is obtained.