IP-Level Satellite Link Emulation with KauNet

Distributed applications and transport protocols communicating over a satellite link may react very strongly to conditions specific to that kind of link. Providing a evaluation framework to allow tests of real implementations of such software in that context is quite a challenging task. In this paper we demonstrate how the use of the general-purpose KauNet IP-level emulator combined with satellite-specific packet loss patterns can help by reproducing losses and delays experienced on a satellite link with a simple Ethernet LAN setup. Such a platform is an essential tool for developers performing continuous testing as they provide new features for e.g. video codecs or transport-level software like DCCP and its congestion control components

Development of a Hybrid Simulation and Emulation Testbed For VANETs

In the area of Intelligent Transportation System traffic efficiency and safety for users have become very popular topics and have triggered extensive research in Vehicular Ad-Hoc Networks (VANETs). Traditional methods for reaserch and development like field testing and simulation have been used. But field testing is usually very expensive and simulation lacks accuracy in wireless environments. This article aims to introduce a hybrid solution that combines the simulation and emulation methods. The proposed solution is implemented in a testbed for VANETs. The resulting testbed would allow multiple real routing instances to run simultaneously on a simulated environment. And to provide performance measures such as resource consumption and scalability

Définition et mise en oeuvre d'une solution d'émulation de réseaux sans fil

Pour évaluer et tester des applications et des protocoles de transport dans un réseau sans fil, il existe différentes méthodes parmi lesquelles l'émulation, un compromis entre le test en environnement réel et la simulation. Dans cette thèse nous présentons W-NINE une nouvelle solution d'émulation centralisée de niveau IP pour les réseaux sans fil qui s'intéresse à trois points : la précision des modèles utilisés, la préservation de leur comportement dynamique et la reproduction fidèle d'une même expérience plusieurs fois de suite. Pour cela, nous proposons une architecture originale utilisant une phase de simulation préalable à l'émulation et des observateurs au cours de l'émulation pour tenir compte des effets liés au trafic circulant dans le réseau sans fil. Une évaluation expérimentale de la plate-forme W-NINE a été menée pour montrer la concordance des résultats obtenus lors de chaque phase ainsi que l'amélioration du réalisme obtenu grâce à l'utilisation d'observateurs de trafic. ABSTRACT : In wireless networks, several solutions are possible to test and evaluate transport protocols or applications among which there is emulation, a compromise between live test and simulation. In this thesis, we present W-NINE a new fully centralized wireless emulation solution which works at the IP level. W-NINE focuses on three points : the precision of models used, the preservation of their dynamic behaviour and the ability to precisely reproduce an experiment from a run to another. To deal with these three aspects, an original architecture that uses a simulation phase prior to emulation is proposed. Moreover, we introduce network observers which are used to deal with trafic-based effects that can occur in a wireless network (e.g. hidden terminals). An experimental evaluation of W-NINE has been made to show the viability of this approach by comparing results obtained during the simulation phase and the emulation phase and to show the increase in realism obtained by network observers