Learn More
—Spatial Principal Component Analysis (PCA) has been proposed for network-wide anomaly detection. A recent work has shown that PCA is very sensitive to calibration settings, unfortunately, the authors did not provide further explanations for this observation. In this paper, we fill this gap and provide the reasoning behind the found discrepancies. First, we(More)
— In opportunistic networks, end-to-end paths between two communicating nodes are rarely available. In such situations, the nodes might still copy and forward messages to nodes that are more likely to meet the destination. The question is which forwarding algorithm offers the best trade off between cost (number of message replicas) and rate of successful(More)
This paper analyzes the characteristics of a multi-hop 802.11b mobile ad hoc network. We present data gathered from a mobile network of 20 devices carried by test users over 5 days in an indoor environment. The data is analyzed with regard to (i) the number of reachable devices, (ii) the node degree, (iii) the average path length, (iv) the link lifetime,(More)
f~bstract— Schemes based on the tagging of packets have recently been proposed as a low-cost way to augment the single class best effort service model of the current Inter-net by including some kind of service discrimination. Such schemes have a number of attractive feat m-es, however, it is not clear exactly what kind of service they would provide to(More)
The research community worldwide has increasingly drawn its attention to the weaknesses of the current Internet. Many proposals are addressing the perceived problems, ranging from new enhanced protocols to fix specific problems up to the most radical proposal to redesign and deploy a fully new Internet. Most of the problems in the current Internet are(More)
The security level of networks and systems is determined by the software vulnerabilities of its elements. Defending against large scale attacks requires a quantitative understanding of the vulnerability lifecycle. Specifically, one has to understand how exploitation and remediation of vulnerabilities, as well as the distribution of information thereof is(More)
Active queue management (AQM) is a family of packet dropping mechanisms for FIFO queues that have been proposed to support end-to-end congestion control mechanisms in the Internet. In this paper, we examine the four possible combinations of queue size averaging vs instantaneous queue size and a sharp dropping function vs a smooth dropping function. The(More)
Allowing mobile users to find and access resources available in the surrounding environment opportunistically via their smart devices could enable them to create and use a rich set of services. Such services can go well beyond what is possible for a mobile phone acting alone. In essense, access to diverse resources such as raw computational power, social(More)