basic of erlang theory

Hi, Arun,
erlang theory can be аpplied for Poisson processes. Traffic is measured in terms of traffic intensity. Traffic intensity
is commonly measured in the unit of Erlang. An Erlang is defined as the average number of simultaneous calls.Many network management systems measure the number of calls during 1-hr
intervals.For example, if the same base station logs a total usage of 72,000 sec
(1,200 min) between 8:00 A.M. and 9:00 A.M., then the traffic intensity is
72 000sec/3 600sec = 20 Erlangs
or
1,200 min/60 min = 20 Erlangs.
You better find some books on teletraffic engineering.
Wish you luck