A software framework for alleviating the effects of MAC-aware jamming attacks in wireless access networks

The IEEE 802.11 protocol inherently provides the same long-term throughput to all the clients associated with a given access point (AP). In this paper, we first identify a clever, low-power jamming attack that can take advantage of this behavioral trait: the placement of a lowpower jammer in a way that it affects a single legitimate client can cause starvation to all the other clients. In other words, the total throughput provided by the corresponding AP is drastically degraded. To fight against this attack, we design FIJI, a cross-layer anti-jamming system that detects such intelligent jammers and mitigates their impact on network performance. FIJI looks for anomalies in the AP load distribution to efficiently perform jammer detection. It then makes decisions with regards to optimally shaping the traffic such that: (a) the clients that are not explicitly jammed are shielded from experiencing starvation and, (b) the jammed clients receive the maximum possible throughput under the given conditions. We implement FIJI in real hardware; we evaluate its efficacy through experiments on two wireless testbeds, under different traffic scenarios, network densities and jammer locations. We perform experiments both indoors and outdoors, and we consider both WLAN and mesh deployments. Our measurements suggest that FIJI detects such jammers in realtime and alleviates their impact by allocating the available bandwidth in a fair and efficient way. © Springer Science+Business Media

Research Statement

My research efforts focus on wireless mesh networks and WLANs, concentrating on the three lowest layers of the network stack. I am interested in design, modeling, measurements and implementations, especially for wireless crosslayer mechanisms. My work is mainly on interference mitigation mechanisms and spans two wireless technologies, (a) the IEEE 802.11 and (b) impulse-based UWB. On wireless LANs and mesh networks, I am interested in measurementbased methodologies, as well as kernel-level implementations for performance improvement algorithms [1], [2]. On UWB my research includes multi-band MAC protocols [3], [4] that manage to utilize efficiently the available spectrum and alleviate interference effects. • Publications: Currently I have 12 publications in high-class journals and conferences. In particular, I have 2 published journal papers and 10 conference/workshop papers. My journal papers have been published in IEEE Transactions on Mobile computing and in Wiley Journal of Wireless communications and Mobile computing. My conference papers have been published in INFOCOM, MOBICOM, SECON, PAM, ICCCN and other popular international conferences and workshops. Moreover, I currently have 5 pending paper submissions, from which 2 have been submitted to journals and 3 to conferences. • Measurement, Simulation and Analytical Tools: I have designed, deployed and maintained wireless testbeds for 802.11 networks, as well as simulators and analytical frameworks for impulse-based UWB. In particular: – I have designed, constructed, deployed and administered two large-scale wireless testbeds [5], [6], [1] at th

MDG: measurement-driven guidelines for 802.11 wlan design

Dense deployments of WLANs suffer from increased interference and as a result, reduced capacity. There are three main functions used to improve the overall network capacity: a) intelligent frequency allocation across APs, b) load-balancing of user affiliations across APs, and c) adaptive power-control for each AP. Several algorithm