Implementation of Jamming Defense Strategies for realtime traffic

Implementation of Jamming Defense Strategies for real-time traffic in Wireless Networks Presenter: Yinglin Sun Oct 7, 2008

Wireless Jamming • Wireless jamming aims at blocking wireless communication by keeping the medium busy or by corrupting received signal using radio interference. • Attack strategies – Scanning: Attack radio keeps hopping until it finds a channel that has legitimate activity. It will stay until it detects lack of activity. – Sweeping: Attackers periodically and simultaneously switch channels irrespective of channel activity, and jam until the next period.

Channel Hopping • There are some orthogonal radio channels in many wireless standards. – 802. 11 a: 12 channels, 802. 15. 4: 16 channels • Channel hopping, whereby radios switch channels to escape jamming, has been proposed to mitigate jamming. – Reactive hopping: each radio stays at current channel till jamming is detected. – Proactive hopping: radios switch channels periodically.

Course project ideas • Tune up jamming defense strategies based on channel hopping for real-time traffic in wireless networks, like Vo. IP, streaming video. • Set up a real experimental wireless network to do experiments • What we have – 5 PCI wireless cards, 1 USB wireless adapter – Sender & receiver: Switched channels with Wireless tools for Linux – Jammer: working on modifying madwifi driver to bypass MAC-layer protocols • Looking for a teammate

Thanks

Question 1 • Which defense strategy (reactive or proactive) achieves the best jamming resiliency under a given system and attack scenario? • Sherif Khattab showed reactive defense provides better jamming tolerance than proactive when considering communication availability in multi-radio wireless networks with simulation.

Multi-radio wireless network • Multi-radio wireless network can be used to increase overall network capacity by exploiting channel diversity, and communication reliability by sending redundant data. • Error-correcting Codes (ECC): (n, m) – Augmented data is divided into n pieces and sent out. – Any m of n pieces can restore original data. • Trade-off between goodput and reliability

Question 2 • How to maximizing network goodput under jamming attacks in multi-radio networks by combining channel-hopping and error-correcting codes(ECC)? • Sherif described the solution space , developed a model of the reactive channelhopping defense against the scanning jamming attack, and validated it with simulation experiments.