Extending the PlanetLab usage model for distributed heterogeneous research testbeds

Distributed research testbeds play a fundamental role in the evaluation of disruptive innovations for Next Generation networks. In recent years, the main research funding agencies have promoted several initiatives aimed at building large-scale infrastructures that could be used to support research in the area of networking and distributed applications. To maximize the benefit/cost ratio, multiple concurrent experiments should be able to use the infrastructure resources at the same time. However, concurrency of resource usage might lead to interference and produce meaningless and not replicable results. This problem has already been addressed in several testbeds, usually by the adoption of proper mechanisms to guarantee the isolation of experiments. The OneLab research project aims at building a European-scale research infrastructure federated with PlanetLab. One of the peculiarities of OneLab is the heterogeneity of access networking technologies (e.g. UMTS, WiFi, WiMax, WMNs, ...). The PlanetLab usage model, based on the concept of slice and implemented by means of the VServer virtualization system in the testbed nodes, is not completely suitable to face the intrinsic heterogeneity of resources in OneLab. In this paper we propose a few extension to the PlanetLab usage model that we intend to introduce in OneLab in order to better support heterogeneous resource sharing. The main purpose of this paper is to present work-in-progress and to stimulate discussion on this specific issue among participants of the ROADS workshop.