Calculating the normalization constants in queueing networks Original Research Article

Many queueing network models have a product-form solution for their steady-state probability distributions. However, the calculation of the normalization constants involved in the solutions is nontrivial. Recently, Gordon proposed a method to derive the closed form formula for normalization constants for certain closed networks. In this paper, we describe a simpler method using Z-transform. In the cases of networks of multiple server queues or of single server queues with equal traffic intensities, the computation involved in proposed approach is much simpler than that in Gordonʹs paper. For multichain closed networks, we propose to use FFT (Fast-Fourier-Transform) to calculate the normalization constants.