Jean-Chrysostome Bolot

Learn More
Excessive packet loss rates can dramatically decrease the audio quality perceived by users of Internet telephony appli cations Recent results suggest that error control schemes using forward error correction FEC are good candidates for decreasing the impact of packet loss on audio quality With FEC schemes redundant information is transmitted along with the(More)
We describe a mechanism for scalable control of multicast continuous media streams. The mechanism uses a novel probing mechanism to solicit feedback information in a scalable manner and to estimate the number of receivers. In addition, it separates the congestion signal from the congestion control algorithm, so as to cope with heterogeneous networks. This(More)
We use the measured round trip delays of small UDP probe packets sent at regular time intervals to characterize the end-to-end packet delay and loss behavior in the Internet. By varying the interval between probe packets, it is possible to study the structure of the In-ternet load over diierent time scales. In this paper, the time scales of interest range(More)
The current Internet provides a single class best ef fort service. From an application's point of view, this service amounts in practice to providing channels with time-varying characteristics such as delay and loss distri butions. One way to support real time applications such as interactive audio given this service is to use control mecha nisms that(More)
Entities in the Internet, ranging from individuals and enterprises to service providers, face a broad range of epidemic risks such as worms, viruses, and botnet-driven attacks. Those risks are interdependent risks, which means that the decision by an entity to invest in security and self-protect affects the risk faced by others (for example, the risk faced(More)
The single class best effort service available in the current Internet does not provide the guarantees, typically expressed in terms of minimum bandwidth and/or maximum delay or loss, associated with real-time applications such as live video. One way to support such applications in best effort networks is to use control mechanisms that adapt the coding,(More)
Dynamic spectrum access approaches, which propose to opportunistically use underutilized portions of licensed wireless spectrum such as cellular bands, are increasingly being seen as a way to alleviate spectrum scarcity. However, before DSA approaches can be enabled, it is important that we understand the dynamics of spectrum usage in licensed bands. Our(More)
We analyze a massive social network, gathered from the records of a large mobile phone operator, with more than a million users and tens of millions of calls. We examine the distributions of the number of phone calls per customer; the total talk minutes per customer; and the distinct number of calling partners per customer. We find that these distributions(More)