Queues Applied to Telecoms

Preface

Queues are omnipresent in communication networks functioning in packet mode. We find them in every computer, router and radio access point. They are veritable funnels whose purpose is to maximize the use of network resources. It is at this level that policies for sharing among users through scheduling and the selective rejection of packets are established. When numerous data transfers share the same link, the system made up of the ensemble of files being transferred can itself be seen as a virtual queue, distributed from servers where the files being transferred are stored.

By extension, network models with circuit switches are considered a particular type of queue, given that there is no wait, since flows are simply allowed or rejected. In certain cases, as with mobile phone networks or call centers, an operator can set up a system that places calls on hold for more or less time, with the hope that a resource might soon become available. Formally speaking, we should thus speak of waiting and rejection lines; usage, however, dictates that the simpler term “queue” be used.

The theorization of teletraffic consists of studying the uses of resources made available to users in any system, and more specifically systems with delay times. For the case of telecommunications, it provides a means for planning a network, or the components of this network.

We can cite a number of objectives in the study of teletraffic: controlling planning that has already been developed, discovering ...