A simple approximation for the Erlang loss function

Abstract

In this paper we present a simple non-iterative computational procedure for approximating the Erlang loss function B(N, ϱ). It is applicable to the practical range 10−5<B(N, ϱ)<10−1 and gives results that are within 10% of the exact values. The formula can be computed on a pocket calculator in constant time and could be used to approximately compute B(N, ϱ) for systems of practically any size.