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Arshad ALI
État académique
Thèse soutenue le 2012-11-12
Sujet: Le codage pour améliorer le transport fiable dans les DTNs
Direction de thèse:
Ellipse bleue: doctorant, ellipse jaune: docteur, rectangle vert: permanent, rectangle jaune: HDR. Trait vert: encadrant de thèse, trait bleu: directeur de thèse, pointillé: jury d'évaluation à mi-parcours ou jury de thèse.
Productions scientifiques
A new reliable transport scheme in delay tolerant networks based on acknowledgments and random linear coding
We propose a new reliable transport scheme for Delay Tolerant Networks (DTNs) based on the use of acknowledgments (ACKs) as well as coding. We, speci cally, develop a uid-limit model to derive expressions for the delay performance of the proposed reliable transport scheme and derive the optimal setting of the parameters which minimize the le transfer time. Our results yield optimal values for the number of outstanding random linear combinations to be sent before time-out as well as the optimal value of the time-out itself, which, in turn, minimize the le transfer time.
Proceedings of the 2011 23rd International Teletraffic Congress ITC 2011 ITC - 23rd International Teletraffic Congress - 2011proceeding with peer review 2011-09-06
Estimating File-Spread in Delay Tolerant Networks under Two-Hop Routing
We consider a Delay/Disruption Tolerant Network under two-hop routing. Our objective is to estimate and track the degree of spread of a message/file in the network. Indeed, having such real-time information is critical for on-line control of routing and energy expenditure. It also benefits the multi-casting application. With exponential inter-meeting times of mobile nodes: (i) for the estimation problem, we obtain exact expressions for the minimum mean-squared error (MMSE) estimator, and (ii) for the tracking problem, we first derive the diffusion approximations for the system dynamics and the measurements and then apply Kalman filtering. We also apply the solutions of the estimation and filtering problems to predict the time when a certain pre-defined fraction of nodes have received a copy of the message/file. Our analytical results are corroborated with extensive simulation results.
Lecture Notes in Computer Science NETWORKING 2012: Lecture Notes in Computer Scienceproceeding with peer review 2012-05-25
A new proposal for reliable unicast and multicast transport in Delay Tolerant Networks
We propose a new scheme for reliable transport, both for unicast and multicast flows, in Delay Tolerant Networks (DTNs). Reliability is ensured through the use of Global Selective ACKnowledgements (G-SACKs) which contain detailed (and potentially global) information about the receipt of packets at all the destinations. The motivation for using G-SACKs comes from the observation that one should take the maximum advantage of the contact opportunities which occur quite infrequently in DTNs. We also propose sharing of "packet header space" with G-SACK information and allow for random linear coding at the relay nodes. Our results from extensive simulations of the proposed scheme quantify the gains due to each new feature.
Personal Indoor and Mobile Radio Communications (PIMRC), 2011 IEEE 22nd International Symposium on Personal Indoor and Mobile Radio Communications (PIMRC), 2011 IEEE 22nd International Symposium onproceeding with peer review 2011-09-11
Thèse: Transport Fiable, Estimation et Poursuite dans les Réseaux Delay Tolerant Networks (DTNs)
Soutenance: 2012-11-12
Rapporteurs: Konstantin AVRACHENKOV    Tamer BASAR