Claude Chaudet

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Reduction of unnecessary energy consumption is becoming a major concern in wired networking, because of the potential economical benefits and of its expected environmental impact. These issues, usually referred to as “green networking”, relate to embedding energy-awareness in the design, in the devices and in the protocols of networks. In this work, we(More)
Since 2005, IEEE 802.11-based networks have been able to provide a certain level of quality of service (QoS) by the means of service differentiation, due to the IEEE 802.11e amendment. However, no mechanism or method has been standardized to accurately evaluate the amount of resources remaining on a given channel. Such an evaluation would, however, be a(More)
Network measurement is essential for assessing performance issues, identifying and locating problems. Two common strategies are the passive approach that attaches specific devices to links in order to monitor the traffic that passes through the network and the active approach that generates explicit control packets in the network for measurements. One of(More)
This article presents a theoretical modeling of a small but basic scenario that shows a great inequity in medium access between nodes using the IEEE 802.11 DCF mode. In this configuration, two terminals evolve independently and are almost never synchronized, which results in a serious performance issue for a third emitter in between. The results are(More)
We propose a new technique to estimate the available bandwidth of wireless nodes and by extension of one-hop links in IEEE 802.11-based ad hoc networks. Our technique exploits the fact that a node can estimate the channel occupancy by monitoring its environment. It provides a non-intrusive estimation meaning that it doesn't generate additional traffic to(More)
In this paper, we experiment different ad hoc configurations that have been pointed out in the literature for presenting some performance problems with IEEE 802.11 MAC protocol. We focus on fairness issues and show that some problems identified by simulation are real and should be considered while others are softened and some are even nonexistent due to(More)
In this article, we propose a method to enhance accuracy of the available bandwidth estimation in IEEE 802.11-based ad hoc networks. This method combines medium state monitoring, probability of collision estimation and backoff time evaluation, improving the method described in [6]. We evaluate our solution by simulation on different scenarios and compare it(More)
Positioning systems in self-organizing networks generally rely on measurements such as delay and received signal strength, which may be difficult to obtain and often require dedicated equipment. An alternative to such approaches is to use simple connectivity information, that is, the presence or absence of a link between any pair of nodes, and to extend it(More)