Bi-weekly meeting. Invited Talk: Oliver Waldhorst - Overlay meets DTN - Hybrid Routing in Delay Tolerant Networks

The talk takes place at 13:30h in S2/02, Room A102.


  Delay Tolerant Networks (DTNs) have emerged as communication paradigm for providing end-to-end routing without costly infrastructure. Nevertheless, empirical studies have shown that opportunistically integrating encountered infrastructure—e. g. 

Internet access via WiFi—into hybrid DTNs can significantly boost routing performance. However, designing hybrid DTNs is both complex and poorly understood. In this talk, we present the overlay-based Hybrid Routing System (HRS) which is—to the best of our knowledge—the first decentralized and collaborative routing approach for hybrid DTNs that does not rely on central servers. With HRS, a large class of existing DTN protocols can now benefit from non-deterministic infrastructure encounters. We characterize this class in an extensive analysis of existing DTN protocols, and exemplarily integrate three prominent representatives (Prophet, MaxProb, and Spray&Focus) into HRS. In an extensive simulation study we show that (1) routing towards the infrastructure first is the dominating strategy for these protocols and (2) HRS effectively bridges geographic distances via the Internet without extensive message replication. In summary, hybrid routing significantly boosts DTN performance as, e. g., only 30% of nodes with Internet access increase delivery probability by 250% for MaxProb in the considered setting.


Short vita:

  Oliver P. Waldhorst received a Diplom-Informatiker degree (comparable to M.Sc. in computer science) in 2000 and a Ph.D. in computer science in 2005, both from University of Dortmund, Germany. 

Recently, he completed a Habilitation (postdoctoral lecture

qualification) at the Computer Science Department of Karlsruhe Institute of Technology (KIT), Germany. Dr. Waldhorst is currently an assistant professor at KIT, where he is leading a 'Young Investigator Group', an independent junior research group funded by the 'Concept for the Future' of KIT within the framework of the German Excellence Initiative. From September 2009 to February 2010 he was a Visiting Researcher in the group of Prof. Liebeherr at University of Toronto, ON, Canada. From April 2011 to March 2012 he will be a Visiting Professor at Technical University of Ilmenau, Germany.