SUMMARY Packet traces are important objects in networking, commonly used in a wide set of applications, including monitoring, troubleshooting, measurements, and validation, to cite a few. Many tools exist to produce and process such traces, but they are often too specific; using them as a basis for creating extended tools is then impractical. Some other tools are generic enough, but exhibit performance issues. This paper reports on our experience designing WiPal, a packet trace manipulation framework with a focus on IEEE 802.11. WiPal is designed for performance and re‐usability, while introducing several novel features compared to previous solutions. Besides presenting how WiPal's original design can benefit packet processing programs, we discuss a number of issues a program designer might encounter when writing packet trace processing software. An evaluation of WiPal shows that, albeit generic, it does not impact performance regarding execution speed. WiPal achieves performance levels observed only with specialized code and outperforms some well‐known packet processing programs. Copyright © 2011 John Wiley & Sons, Ltd.

Clock synchronization is particularly challenging in resource constrained networks. This paper presents an accurate, coherent and bandwidth efficient synchronization scheme called TurboSync. Unlike traditional solutions that synchronize pairs of nodes, TurboSync is able to synchronize entire node clusters. TurboSync relies on principal component analysis with missing data. Packets are broadcasted on the medium and their capture times at each node side are used to compute the clock conversion parameters. To have a complete and usable set of capture times for each broadcast, we propose to fill out the missing packet timestamps at the transmitters' side using an inference mechanism. TurboSync synchronizes all the clocks in the cluster at a time which leads to coherent clock conversion between nodes. Our performance results show better accuracy compared to the RBS protocol.

In order to reduce the amount of radio communications, wireless sensor networks may perform data aggregation, where relaying nodes perform in-network processing. Guaranteeing security in aggregation schemes is particularly challenging because node compromises in such a scenario are doubly problematic, both in terms data confidentiality (eavesdropping) and availability (denial of service). Indeed, by compromising an aggregator node the attacker would endanger all of the readings that are part of the aggregate the node is in charge of.