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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Design And Implementation Of Scheduling And Switching Architectures For High Speed Networks

Sanli, Mustafa 01 October 2011 (has links) (PDF)
Quality of Service (QoS) schedulers are one of the most important components for the end-to-end QoS support in the Internet. The focus of this thesis is the hardware design and implementation of the QoS schedulers, that is scalable for high line speeds and large number of traffic flows. FPGA is the selected hardware platform. Previous work on the hardware design and implementation of QoS schedulers are mostly algorithm specific. In this thesis, a general architecture for the design of the class of Packet Fair Queuing (PFQ) schedulers is proposed. Worst Case Fair Weighted Fair Queuing Plus (WF2Q+) scheduler is implemented and tested in hardware to demonstrate the proposed architecture and design enhancements. The maximum line speed that PFQ algorithms can operate decreases as the number of scheduled flows increases. For this reason, this thesis proposes to aggregate the flows to scale the PFQ architecture to high line speeds. The Window Based Fair Aggregator (WBFA) algorithm that this thesis suggests for flow aggregation provides a tunable trade-off between the efficient use of the available bandwidth and the fairness among the constituent flows. WBFA is also integrated to the hardware PFQ architecture. The QoS support provided by the proposed PFQ architecture and WBFA is measured by conducting hardware experiments on a custom built high speed network testbed which consists of three data processing cards and a backplane. In these experiments, the input traffic is provided by the hardware traffic generator which is designed in the scope of this thesis.
2

Agrégation de trafic pour réduire la consommation énergétique globale dans les réseaux sans fil multi-sauts / Traffic aggregation for global energy savings in multi-hop wireless networks

Laubé, Alexandre 25 September 2017 (has links)
Les incitations économiques et environnementales poussent dorénavant à intégrer des considérations énergétiques dès les premiers stades de développement des réseaux. Dans les réseaux sans fil multi-sauts, l'approche la plus courante consiste à répartir le trafic sur l'ensemble des nœuds afin de réduire équitablement la consommation énergétique de chacun, avec pour objectif la maximisation de la durée de vie du réseau. Or cette approche n'est pas optimale vis-à-vis de la consommation globale du réseau, le niveau d'activité d'un nœud n'ayant souvent que peu d'influence sur sa propre consommation. Nous montrons que la meilleure approche consiste à éteindre un maximum de nœuds. Parmi les travaux réalisés, nous avons développé une solution s'appuyant sur de la programmation linéaire en nombres entiers et des simulations de graphes et de réseaux. La solution proposée permet ainsi une agrégation de flux optimale, réduisant significativement le nombre de nœuds utilisés dans le réseau. Afin de la rendre applicable en pratique, une heuristique est détaillée permettant une mise en œuvre distribuée grâce à l'utilisation d'une métrique de routage. Ainsi, tout algorithme de plus court chemin peut nativement réaliser de l'agrégation de flux efficace. Il est important de souligner que la qualité de service en termes de débit est respectée. En effet, les interférences sont prises en compte et il est possible de profiter de la synergie offerte par l'utilisation conjointe de l'agrégation de flux et du codage réseau. Nos résultats améliorent significativement les méthodes d'économie d'énergie basées sur l'extinction des nœuds en leur permettant d'en éteindre davantage. / Economic and ecologic incentives are now leading people to design networks with energetic considerations at early stages of development. Most of the works for multi-hop wireless networks tend to spread the traffic uniformly over the network to reduce the energy consumption of each node individually. However, considering that the traffic of a node doesn't impact significantly its energy consumption, this approach is not optimal regarding the global energy consumption of the network. Finding a way to turnoff as much node as possible seems then to be a better way. This PhD thesis focus on routing a set of flows over a multi-hop wireless network while minimizing the number of used nodes. This is done by using a distributed metric that allows the shortest path routing algorithms to perform flow aggregation. Using integer linear programming and simulations, we proposed an efficient solution to aggregate flows to significantly reduce the number of nodes used in the network. It allows, then, to improve algorithms that reduce the energy consumption of networks by increasing the number of nodes that can be turned off.

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