A Note on Simple Eigenvalues of Matrix Polynomials in Queueing Models with Erlang Distributions

Abstract

In this note, we study an Ek/Em/1 queueing model where interarrival and service times are Erlang distributions with parameters k and m respectively. We prove that the roots of the characteristic polynomial associated with Erlang distributions are simple if the arrival and service rates are real. Based on this result, a general solution space of vectors for stationary probabilities is easily constructed.