Thomas Hühn

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With wireless technologies becoming prevalent at the last hop, today’s network operators need to manage WiFi access networks in unison with their wired counterparts. However, the non-uniformity of feature sets in existing solutions and the lack of programmability makes this a challenging task. This paper proposes Odin, an SDN-based solution to bridge this(More)
A substantial variety of control algorithms to adjust carrier sensing, transmission power, and transmission rate have been proposed for IEEE 802.11 wireless networks in the recent literature. Their objectives range from maximizing throughput, spatial reuse, and fairness to minimizing interference and congestion within the network. However, only a few of(More)
The Berlin Open Wireless Lab (BOWL) project at Technische Universität Berlin (TUB) maintains an outdoor WiFi network which is used both for Internet access and as a testbed for wireless research. From the very beginning of the BOWL project, we experienced several development and operations challenges to keep Internet users and researchers happy. Development(More)
Even though hot spots and mesh networks increasingly realize the long-standing vision of ubiquitous Internet access, our understanding of wireless protocols and system is still in its infancy. To analyze and debug the current and new protocols, packet-level accurate information of protocol status is crucially needed. Thus, this paper introduces PaPMo(More)
While there has been extensive theoretical work on sophisticated joint resource allocation algorithms for wireless networks, their applicability to WiFi (IEEE 802.11) networks is very limited. One of the main reasons is the limitations in changing MAC parameters in current driver implementations. To this end, in this work, we developed a general cross-layer(More)
Wireless networking research lacks a comprehensive experimental environment that supports implementation, validation, deployment, performance evaluation and comparison of research ideas. While some open wireless testbeds [1, 2] have taken important steps to create such an environment, they typically provide researchers only access to a set of mesh nodes, an(More)
This testbed practice paper presents our efforts to validate an analytical model for fluid flow behavior in wireless mesh networks with an experimental evaluation. We have developed a fluid model for multihop communication in wireless mesh networks and analyzed it with simulations. Now, we describe our efforts to reproduce the modeled and simulated network(More)
Wireless mesh networks have the potential to provide ubiquitous high-speed Internet access at low costs. The good news is that initial deployments of WiFi meshes show the feasibility of providing ubiquitous Internet connectivity. However, their performance is far below the necessary and achievable limit. Moreover, users’ subscription in the existing meshes(More)
The threat of denial of service flooding attacks in the Internet is rapidly increasing. Especially the use of techniques that allow attackers to hide their attack traffic raises concerns: attack distribution and rotation in botnets to obfuscate senders, low-rate bandwidth attacks, and attacks that mimic realistic patterns such as flash crowds. The defense(More)