Supervision : Serge FDIDA

Co-supervision : IANNONE Luigi

Transparent Mobility Management in a Real Wireless Mesh Environment

Over the last decade, we have witnessed a great success of wireless communications. In our daily life, most of electronic devices are equipped with a wireless interface, allowing users to be more mobile and pervasive. This requires specific communication architectures that respond to the challenges imposed by new user behaviors. Wireless mesh networks fall in this category. Indeed, with their two-tiered architecture, they concentrate routing on a stable wireless backbone, while mobile clients are totally free to move around. In this context, one of the main challenges is to provide an efficient localization service so that clients can communicate with each other in a transparent way. This thesis investigates micro-mobility issues in wireless mesh networks by analyzing mobility management performance on real testbeds through measurements. The contributions are threefold: Enhanced mobility management. Most of existing solutions rely on some variant of full or partial flooding, which causes the well known broadcast storm problem, and very often they need support from end-users' devices. To deal with this latter issue, we propose Enhanced Mobility Management (EMM), a new efficient solution that does not rely on any modification or additional software on client side, thus being totally transparent for end-users. EMM takes advantage of the existing Neighbor Discovery Protocol (NDP) cache to keep track of the latest association and uses this information to trigger an update in order to re-route packets. Measurements show that EMM significantly improve performance of mobility management. DHT-based location management. We design, implement, and test LORD, a new DHT-based scalable location management scheme through logical and experimental evaluation on our wireless mesh testbed. The main features of our proposed scheme are that broadcast packets are totally avoided and node localization is transparent to users. We compare it to our previous flooding-based location scheme (EMM). Our results show improved performance both in terms of percentage of dropped packets and handover latency introduced to re-establish open sessions after a user movement. Link stability. Finally, to study the stability of our DHT approach, we investigate stability of links in wireless environments. We address some interesting questions related to persistence and prevalence of both dominant and sub-dominant routes between nodes in a real deployment. We note that source-destination pairs mostly use the dominant route and the two most sub-dominant routes to communicate. We also investigate the impact of the distance between a source and a destination on stability of routes. It turns out that the longer the distance, the larger the number of sub-dominant routes.

2008-2017 Publications

• 2017
  • S. BELOUANAS, M. Bezahaf, K.‑L. Thai, P. Spathis, M. Dias De Amorim : “Leveraging Node Gatherings to Save Cellular Resources”, Annals of Telecommunications - annales des télécommunications, (Springer) (2017)
• 2012
  • M. Bezahaf, L. Iannone, M. Dias De Amorim, S. Fdida : “An experimental evaluation of cross-layer routing in a wireless mesh backbone”, Computer Networks, vol. 56 (5), pp. 1568-1583, (Elsevier) (2012)
• 2011
  • M. Bezahaf, L. Iannone, M. Dias De Amorim, S. Fdida : “LORD: Tracking mobile clients in a real mesh”, Ad Hoc Networks, vol. 9 (8), pp. 1461-1475, (Elsevier) (2011)
• 2010
  • M. Bezahaf : “Gestion Transparente de la Mobilité dans un Environnement Maillé Sans-Fil Réel”, thesis, phd defence 12/09/2010, supervision Fdida, Serge, co-supervision : Iannone, Luigi (2010)
  • M. Bezahaf, L. Iannone, M. Dias De Amorim, S. Fdida : “Insights into the Routing Stability of a Multi-hop Wireless Testbed”, ADHOCNETS 2010 - 2^nd International Conference on Ad Hoc Networks, vol. 49, Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering, Victoria, BC, Canada, pp. 82-97, (Springer) (2010)
• 2009
  • M. Bezahaf, Th. Begin, B. Baynat, S. Fdida : “Note sur les performances de TCP dans un environnement sans-fil multisaut”, Colloque francophone sur l'ingenierie des protocoles (CFIP'09), Strasbourg, France, pp. 1-3 (2009)
  • M. Bezahaf, L. Iannone, M. Dias De Amorim, S. Fdida : “Practical DHT-Based Location Service for Wireless Mesh Networks”, Proceedings of the 5^th international student workshop on Emerging networking experiments and technologies, Rome, Italy, pp. 47-48, (ACM) (2009)
  • M. Bezahaf, L. Iannone, M. Dias De Amorim, S. Fdida : “Transparent and Distributed Localization of Mobile Users in Wireless Mesh Networks”, International ICST Conference on Heterogeneous Networking for Quality, Reliability, Security and Robustness (QShine'09), vol. 22, Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering, Las Palmas de Gran Canaria, Spain, pp. 513-529, (Springer) (2009)
• 2008
  • M. Bezahaf, L. Iannone, S. Fdida : “Gestion avancée de la mobilité dans les réseaux maillés sans fil”, Colloque Francophone sur l'Ingénierie des Protocoles (CFIP 2008), Les Arcs, France (2008)
  • M. Bezahaf, L. Iannone, S. Fdida : “Enhanced Mobility Management in Wireless Mesh Networks”, 9^es Journées Doctorales en Informatique et Réseaux (JDIR 2008), Villeneuve d'Ascq, France (2008)