Call–burst blocking and call admission control in a broadband network with bursty sources

Abstract

In this paper we consider call–burst blocking and call admission control in a broadband network with bursty sources. We assume a multiple-link network with several classes of calls, each class following a fixed path in the network and requiring a fixed number of channels from the links on its path. The arrival of each class of calls is according to a Poisson process and the calls alternate between On and Off periods during the time that they are in the system. At the end of each On period, a call either terminates or begins a new Off period according to a Bernoulli trial. During the Off periods calls release the channels that they are holding which might be assigned to the other On calls, a form of burst multiplexing. A new call is accepted to the system only if the burst-blocking probabilities remain acceptable. It is shown that the product-form solution still applies in the new system and we derive a multi-dimensional recursion to calculate the joint link occupancy distribution. Call and burst blockings as well as probability distribution of the number of burst blockings experienced by each class of calls have also been determined. We determine a simple decision mechanism for call admission. The numerical results show that the burst multiplexing increases the maximum load that the system may handle substantially compared to permanent assignment of the channels. We also discuss the implementation of this model in an ATM environment.