Two-link approximation schemes for loss networks with linear structure and trunk reservation

Mark Bebbington, Phil Pollett and Ilze Ziedins

[Full Text]

Abstract: Loss networks have long been used to model various types of telecommunication network, including circuit-switched networks. Such networks often use admission controls, such as trunk reservation, to optimize revenue or stabilize the behaviour of the network. Unfortunately, an exact analysis of such networks is not usually possible, and reduced-load approximations such as the Erlang Fixed Point (EFP) approximation have been widely used. The performance of these approximations is typically very good for networks without controls, under several regimes. There is evidence, however, that in networks with controls, these approximations will in general perform less well.

We propose an extension to the EFP approximation that gives marked improvement for a simple ring-shaped network with trunk reservation. It is based on the idea of considering pairs of links together, rather than links in isolation, as does the EFP approximation, thus making greater allowance for dependencies between neighbouring links.

Keywords: Approximation, Blocking probabilities, Erlang Fixed Point, Ring network, Trunk reservation

Acknowledgement: This worked was funded by the Australian Research Council.

The authors:

• Mark Bebbington, Department of Statistics, Massey University.
• Phil Pollett, Discipline of Mathematics, The University of Queensland.
• Ilze Ziedins, Department of Mathematics and Statistics, The University of Auckland

Back to Research Communications

Back to PKP's home page

Last modified: 10th September 1998