References of "François, Jean-Marc"
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See detailRouting Based on Delivery Distributions in Predictable Disruption Tolerant Networks
François, Jean-Marc; Leduc, Guy ULiege

in Ad hoc Networks (2009), 7(1), 219-229

This article studies disruption tolerant networks (DTNs) where each node knows the probabilistic distribution of contacts with other nodes. It proposes a framework that allows one to formalize the ... [more ▼]

This article studies disruption tolerant networks (DTNs) where each node knows the probabilistic distribution of contacts with other nodes. It proposes a framework that allows one to formalize the behaviour of such a network. It generalizes extreme cases that have been studied before where (a) either nodes only know their contact frequency with each other or (b) they have a perfect knowledge of who meets who and when. This paper then gives an example of how this framework can be used; it shows how one can find a packet forwarding algorithm optimized to meet the ‘delay/bandwidth consumption’ tradeoff: packets are duplicated so as to (statistically) guarantee a given delay or delivery probability, but not too much so as to reduce the bandwidth, energy, and memory consumption. [less ▲]

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See detailAP and MN-centric Mobility Prediction: A Comparative Study Based On Wireless Traces
François, Jean-Marc; Leduc, Guy ULiege

in Lecture Notes in Computer Science (2007, May), 4479

The mobility prediction problem is defined as guessing a mobile node's next access point as it moves through a wireless network. Those predictions help take proactive measures in order to guarantee a ... [more ▼]

The mobility prediction problem is defined as guessing a mobile node's next access point as it moves through a wireless network. Those predictions help take proactive measures in order to guarantee a given quality of service. Prediction agents can be divided into two main categories: agents related to a specific terminal (responsible for anticipating its own movements) and those related to an access point (which predict the next access point of all the mobiles connected through it). This paper aims at comparing those two schemes using real traces of a large WiFi network. Several observations are made, such as the difficulties encountered to get a reliable trace of mobiles motion, the unexpectedly small difference between both methods in terms of accuracy, and the inadequacy of commonly admitted hypotheses (such as the different motion behaviours between the week-end and the rest of the week). [less ▲]

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See detailDelivery Guarantees In Predictable Disruption Tolerant Networks
François, Jean-Marc; Leduc, Guy ULiege

in Lecture Notes in Computer Science (2007, May), 4479

This article studies disruption tolerant networks (DTNs) where each node knows the probabilistic distribution of contacts with other nodes. It proposes a framework that allows one to formalize the ... [more ▼]

This article studies disruption tolerant networks (DTNs) where each node knows the probabilistic distribution of contacts with other nodes. It proposes a framework that allows one to formalize the behaviour of such a network. It generalizes extreme cases that have been studied before where either (a) nodes only know their contact frequency with each other or (b) they have a perfect knowledge of who meets who and when. This paper then gives an example of how this framework can be used; it shows how one can find a packet forwarding algorithm optimized to meet the delay/bandwidth consumption trade-off: packets are duplicated so as to (statistically) guarantee a given delay or delivery probability, but not too much so as to reduce the bandwidth, energy, and memory consumption. [less ▲]

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See detailPredictable disruption tolerant networks and delivery guarantees
François, Jean-Marc; Leduc, Guy ULiege

Report (2006)

This article studies disruption tolerant networks (DTNs) where each node knows the probabilistic distribution of contacts with other nodes. It proposes a framework that allows one to formalize the ... [more ▼]

This article studies disruption tolerant networks (DTNs) where each node knows the probabilistic distribution of contacts with other nodes. It proposes a framework that allows one to formalize the behaviour of such a network. It generalizes extreme cases that have been studied before where (a) either nodes only know their contact frequency with each other or (b) they have a perfect knowledge of who meets who and when. This paper then gives an example of how this framework can be used; it shows how one can find a packet forwarding algorithm optimized to meet the 'delay/bandwidth consumption' trade-off: packets are duplicated so as to (statistically) guarantee a given delay or delivery probability, but not too much so as to reduce the bandwidth, energy, and memory consumption. [less ▲]

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See detailPrédiction de mobilité par le mobile ou par le point d'accès: comparaison sur base de traces réelles
François, Jean-Marc; Leduc, Guy ULiege

in CFIP'2006 (2006, November)

Le problème de la prédiction de mobilité se définit comme le fait de deviner quel sera le prochain point d'accès rencontré par un terminal mobile lors de son déplacement dans un réseau sans fil. Les ... [more ▼]

Le problème de la prédiction de mobilité se définit comme le fait de deviner quel sera le prochain point d'accès rencontré par un terminal mobile lors de son déplacement dans un réseau sans fil. Les prédictions faites permettent d'améliorer la qualité de service fournie par le réseau en lui permettant de prendre des mesures pro-actives (telles des réservations de ressources). Les agents de prédiction se classent principalement en deux catégories: les agents liés à un mobile particulier (responsables d'anticiper les déplacements de celui-ci) et ceux liés à un point d'accès (prédisant le prochain point d'attache de tous les terminaux y étant connectés). Cet article vise à comparer les deux méthodes à l'aide de traces réelles tirées d'un réseau WiFi de grande taille. Il montre que certains postulats souvent admis (comme le fait que les habitudes de mouvement du week-end sont différentes de celles du reste de la semaine) doivent être revus. [less ▲]

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See detailEntropy-based knowledge spreading and application to mobility prediction
François, Jean-Marc; Leduc, Guy ULiege

in ACM International conference on Emerging Network Experiments and Technologies (2005, October)

The low quality of service provided by wireless networks does not facilitate the setup of long-awaited services, such as video conversations. In a cellular network, handoffs are an important cause of ... [more ▼]

The low quality of service provided by wireless networks does not facilitate the setup of long-awaited services, such as video conversations. In a cellular network, handoffs are an important cause of packet losses and delay jitter. These problems can be mitigated if proactive measures are taken. This requires each cell to guess the next handoff of each mobile terminal, a problem known as mobility prediction. This prediction can occur thanks to some clues (such as signal strength measurements) giving information about the terminals motion. For example, a clue that locates on which road a mobile is moving is likely to be interesting for all the prediction-enabled cells along that road ---and should therefore be sent to them. This paper proposes a new method aimed at selecting the most relevant clues and finding where to propagate those clues so as to optimize mobility predictions. The pertinence of a clue is measured using information theory and by means of decision trees. This pertinence estimation is exchanged between the cells and allows to build a"relevance map" that helps determine where clues should be sent. It is adapted to the characteristics of wireless terminals such as low bandwidth and processing power. [less ▲]

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See detailMobility prediction's influence on QoS in wireless networks: a study on a call admission algorithm
François, Jean-Marc; Leduc, Guy ULiege

(2005, April)

Several mechanisms increase the QoS level of mobile networks thanks to an underlying mobility prediction method (i.e. a means to predict a mobile's next access router). This paper aims at studying how the ... [more ▼]

Several mechanisms increase the QoS level of mobile networks thanks to an underlying mobility prediction method (i.e. a means to predict a mobile's next access router). This paper aims at studying how the accuracy of the prediction method can influence the network QoS in the particular context of call admission control. It shows that (a) the mobiles behaviour must be adapted according to the prediction scheme accuracy in order to achieve good performance and (b) the admission algorithm can be modified to increase its fairness and to give mobiles an incentive to do such an adaptation. [less ▲]

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See detailLearning movement patterns in mobile networks: a generic method
François, Jean-Marc; Leduc, Guy ULiege; Martin, Sylvain ULiege

in European Wireless 2004 (2004, February)

Predicting terminals movements in mobile networks is useful for more than one reason, in particular for routing management. A way to do such prediction is to learn the movement patterns of mobile nodes ... [more ▼]

Predicting terminals movements in mobile networks is useful for more than one reason, in particular for routing management. A way to do such prediction is to learn the movement patterns of mobile nodes passing by an access router. In this paper, the information (e.g. layer 2 measurements) related to the different paths followed by mobiles are learned using a hidden Markov model. Simulations have been done using this method and show it can handle different layer~2 signals and collect statistical information when no such signal is available. Furthermore, the method works when no information is available and can be extended so as to guess the timing of the handoffs. [less ▲]

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See detailEvaluation d'une méthode de prédiction des déplacements de terminaux dans les réseaux mobiles
François, Jean-Marc; Leduc, Guy ULiege; Martin, Sylvain ULiege

in Ingénierie des protocoles - Réseaux mobiles et ad hoc, qualité de service, test et validation (2003, October)

Dans les réseaux mobiles, la prédiction du déplacement des terminaux fait régulièrement l'objet d'études: c'est une étape importante sur le chemin des garanties de QoS dans ces réseaux. Dans les ... [more ▼]

Dans les réseaux mobiles, la prédiction du déplacement des terminaux fait régulièrement l'objet d'études: c'est une étape importante sur le chemin des garanties de QoS dans ces réseaux. Dans les infrastructures actuelles, les sources d'informations permettant d'induire le déplacement d'un mobile sont multiples; de plus, le cas des terminaux incapables d'émettre de telles informations est aussi fréquent qu'important. Dans ces conditions, pour qu'un mécanisme de prédiction puisse se déployer, il lui faut pouvoir s'adapter à cette diversité de façon flexible. L'évaluation d'un tel mécanisme est le sujet de cet article; il s'agit d'une méthode simple et s'appuyant sur peu d'hypothèses. [less ▲]

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