A new service overlays dimensioning approach based on stochastic geometry

The global provisioning of some types of evolved services over the Internet requires the deployment of servers; the approach is usually called service overlays. An optimal design of the number of servers and of their location is critical in order to minimize the deployment cost while providing the quality of service expected by users. In this paper, we propose an original modelling, analysis and optimization approach based on stochastic geometry to deal with this design issue. Two particular cases of service overlays are emphasized: servers deployed for content delivery (i.e. to deploy a content delivery network or CDN) and servers deployed for reliable multicast communications. In our approach, the network topology, the subscribers’ location and the servers’ location are represented by point processes in the plane. Point process theory and Palm Calculus are used in order to obtain closed form expressions for the expected value of realistic cost functions. These closed forms allow us to evaluate the optimal cost of a future deployment. c © 2006 Elsevier B.V. All rights reserved.