Publications de Jean-Yves Le Boudec

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We define a self-limiting epidemic service as a dissemination service for ad-hoc environments that is broadcast in nature, but is limited to a local scope around each source. Example applications are chatting or bulletin boards in a traffic jam, in an instant crowd in a campus or, in contrast, along a desert highway. Our goal is to support such a service across a wide range of conditions (dense or sparse). The main problems are to adaptively control scoping and traffic rates to avoid congestion. We propose

We consider a model for interacting objects, where the evolution of each object is given by a finite state Markov chain, whose transition matrix depends on the present and the past of the distribution of states of all objects. This is a general model of wide applicability; we mention as examples: TCP connections, HTTP flows, robot swarms, reputation systems. We show that when the number of objects is large, the occupancy measure of the system converges to a deterministic dynamical system (the ``mean field")

Packet detection and timing acquisition for IR-UWB networks such as 802.15.4a relies on the presence of an acquisition sequence (or preamble) at the beginning of each packet. A simple network design choice is to use a common acquisition sequence for the whole network. A second design choice is to use an acquisition sequence private to destinations. It potentially yields a larger network throughput, but requires additional complexity for sources to learn the acquisition sequence of their destination. In this

We describe the real-time monitoring infrastructure of the smart-grid pilot on the EPFL campus. We experimentally validate the concept of a real-time state-estimation for a 20 kV active distribution network. We designed and put into operation the whole inf ...

We study the admissibility problem in multivariate algebraic systems, such as ac electrical networks, where the power injection is quadratic in the state. The goal of such systems is to ensure that the state stays in some security set (e.g., magnitudes of ...

It is well known that a simple binary feedback rate--based congestion avoidance scheme cannot ensure a fairness goal of the Available Bit Rate (ABR) service, namely, max--min fairness. In this paper we show how the rates are distributed for the network consisting of the binary switches, and end--systems employing an additive--increase/multiplicative decrease rate control. The modeling assumptions fairly resembles the ABR congestion avoidance, and applies to an arbitrary network topology. The results are obt

We are interested in the design of physical-layer aware medium access control (PHY-aware MAC) for self-organized, low power, low data-rate impulse-radio ultra-wideband (IR-UWB) networks. In such networks, energy consumption is much more of a concern than a ...

In this paper, we consider an active distribution network (ADN) that performs primary voltage control using real-time demand response via a broadcast low-rate communication signal. The ADN also owns distributed electrical energy storage. We show that it is ...

Supercapacitors-based storage systems are expected to play a key role in microgrids in view of their capability to compensate high-power imbalances. We define an agent for the control of supercapacitor arrays within the context of the novel control framewo ...

MPTCP has been proposed as a mechanism to support transparently multiple connections to the application layer and is under discussion at the IETF. It can use effectively the available bandwidth and it improves throughput and fairness, compared to independent TCP flows in many scenarios. However we show, by measurements over our testbed and analytically, that MPTCP still suffers from two problems: (P1) upgrading some TCP users to MPTCP can reduce the throughput of others without any benefit to the upgraded u

The recent literature discusses the use of the relaxed Second Order Cone Programming (SOCP) for formulating Optimal Power Flow problems (OPF) for radial power grids. However, if the shunt parameters of the lines that compose the power grid are considered, ...

We survey recent advances in theories and models for Internet Quality of Service (QoS). We start with the theory of network calculus, which lays the foundation for support of deterministic performance guarantees in networks, and illustrate its applications to integrated services, differentiated services, and streaming media playback delays. We also present mechanisms and architecture for scalable support of guaranteed services in the Internet, based on the concept of a stateless core. Methods for scalable c

A shaper is a system that stores incoming bits in a buffer and delivers them as early as possible, while forcing the output to be constrained with a given arrival curve. A shaper is time invariant if the traffic constraint is defined by a fixed arrival curve, it is time varying if the condition on the output is given by a time varying traffic contract. This occurs, for example, with renegotiable variable bit rate (RVBR) services. We focus on the class of time varying shapers called time varying leaky bucket

This paper gives a technical overview of different networking technologies, such as Internet, ATM. It describes different approaches of how to run IP on top of an ATM network, and assesses their potential to be used as an integrated services network. Keyword List: ATM, IPv4, IPv6, RSVP, differentiated-services, LANE, CLIP, NHRP, MPOA, Arequipa, IP-Switching, Tag-Switching Executive Summary: Current and future applications make use of different technologies as voice, data, and video. Consequently network tec

We consider the problem of multicast routing in a large single domain network with a very large number of multicast groups with small number of receivers. Such a case occurs, for example, when multicast addresses are statically allocated to mobile hosts, as a mechanism to manage Internet host mobility. For such networks, existing dense or sparse mode multicast routing algorithms do not scale well with the number of multicast groups. We introduce an alternative solution called Distributed Core Multicast (DCM

An algorithm that pre-computes a list of routes for each node in the network. An alternate route is also computed in case of overload of the primary one. Simulations show that this algorithm provides routes as good as On-Demand ones.

Energy efficiency, i.e., the amount of battery energy consumed to transmit bits across a wireless link, is a critical design parameter for wireless ad-hoc networks. We examine the problem of broadcasting information to all nodes in an ad-hoc network, when a large percentage of the nodes act as sources. We theoretically quantify the energy savings that network coding can offer for the cases of two regular topologies. We then propose low-complexity distributed algorithms, and demonstrate through simulation th

We study a multiperiod optimal power flow (OPF) problem in unbalanced three-phase radial distribution networks with batteries. To address this problem, we first take the resistance-line battery model that treats lossy batteries by adding resistive lines an ...

Reputation systems in mobile ad-hoc networks can be tricked by the spreading of false reputation ratings, be it false accusations or false praise. Simple solutions such as exclusively relying on one`s own direct observations have drawbacks, as they do not make use of all the information available. We propose a fully distributed reputation system that can cope with false disseminated information. In our approach, everyone maintains a reputation rating and a trust rating about everyone else that they care abo

We compare the performance of ABR and UBR for providing high-speed network interconnection services for TCP traffic. We test the hypothesis that UBR with adequate buffering in the ATM switches results in better overall goodput for TCP traffic than explicit rate ABR for LAN interconnection. This is shown to be true in a wide selection of scenarios. Four phenomena that may lead to bad ABR performance are identified and we test whether each of these has a significant impact on TCP goodput. This reveals that th

Jean-Yves Le Boudec

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Self-Limiting Epidemic Forwarding

A Generic Mean Field Convergence Result for Systems of Interacting Objects

Effect on Network Performance of Common versus Private Acquisition Sequences for Impulse Radio UWB Networks

Real-Time State Estimation of the EPFL-Campus Medium-Voltage Grid by Using PMUs

Admissibility of Uncertain Injections in Quadratic Algebraic Systems

How (Un)Fair are the ABR Binary Schemes, Actually?

Tradeoff Analysis of PHY-aware MAC in Low-Rate, Low-Power UWB networks

Primary Voltage Control in Active Distribution Networks via Broadcast Signals: The Case of Distributed Storage

A SuperCapacitor Agent for Providing Real-Time Power Services to the Grid

Non-Pareto Optimality of MPTCP: Performance Issues and a Possible Solution

An Exact Convex Formulation of the Optimal Power Flow in Radial Distribution Networks Including Transverse Components

Theories and Models for Internet Quality of Service

The Renegotiable Variable Bit Rate Service

IP and ATM - current evolution for integrated services

Distributed Core Multicast (DCM), a routing protocol for IP with application to host mobility

A Path Selection Method in ATM using Pre-Computation

Low-complexity energy-efficient broadcasting in wireless ad-hoc networks using network coding

On the Solution of the Optimal Power Flow for Three-Phase Radial Distribution Networks With Energy Storage

A Robust Reputation System for Mobile Ad-hoc Networks

A comparison of ABR and UBR to support TCP traffic