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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

Performance improvement for mobile ad hoc cognitive packets network

Al-Turaihi, Firas Sabah Salih January 2018 (has links)
In this thesis, focusing on the quality of service (QoS) improvement using per-packet power control algorithm in Ad Hoc Cognitive Packet Networks (AHCPN). A power control mechanism creates as a network-assisted function of ad hoc cognitive packet-based routing and aims at reducing both energy consumption in nodes and QoS requirements. The suggested models facilitate transmission power adjustments while also taking into account the effects on network performance. The thesis concentrate on three main contributions. Firstly, a power control algorithm, namely the adaptive Distributed Power management algorithm (DISPOW) was adopted. Performance of DISPOW was compared to existing mechanisms and the results showed 27, 13, 9, and 40 percent improvements in terms of Delay, Throughput, Packet Loss, and Energy Consumption respectively. Secondly, the DISPOW algorithm was enhanced, namely a Link Expiration Time Aware Distributed Power management algorithm (LETPOW). This approach periodically checks connectivity, transmission power, interference level, routing overhead and Node Mobility in AHCPN. The results show that LETPOW algorithm improves the performance of system. Results show further improvement from DISPOW by 30,25,30,42 percent in terms of delay, packet loss ratio , path lengths and energy consumption respectively. Finally,Hybrid Power Control Algorithm (HLPCA) has presented is a combination of Link Expiration Time Aware Distributed Power management algorithm (LETPOW) and Load Power Control Algorithm (LOADPOW); deal with cross-layer power control applied for transmitting information across the various intermediate layers. LOADPOW emphasis on the concept of transmission Power, Received Signal Strength Indication (RSSI), and the suitable distance between the receiver and the sender. The proposed algorithm outperforms DISPOW and LETPOW by 31,15,35,34,44 percent in terms of Delay, Throughput, Packet Loss,path length and Energy Consumption respectively. From this work, it can be concluded that optimized power control algorithm applied to Ad-hoc cognitive packet network results in significant improvement in terms of energy consumption and QoS.
2

Gestion d'une architecture hétérogène distribuée à l'aide du SDN / Management of a heterogeneous distributed architecture with the SDN

Gonzalez santamaria, Carlos 19 December 2017 (has links)
Les acteurs majeurs d'Internet ont mis en place dans leurs datacenters de plus en plus de virtualisation pour permettre de faire fonctionner plusieurs systèmes d'exploitation simultanément sur un même serveur physique. Cette technologie a permis de faire des économies énergétiques et financières importantes. Elle utilise également au niveau de la recherche depuis peu de temps, en particulier dans le domaine des réseaux. Traditionnellement, ce sont des équipements physiques tels que des commutateurs ou des routeurs qui se chargent du transfert de l'information, à la suite d'une programmation effectuée par les administrateurs. Dorénavant, ces équipements sont également virtualisés et la décision prise pour l'acheminement de l'information se fait de manière logiciel. Des expérimentations de cette technologie de virtualisation du réseau, aussi appelé Software-Defined Network (SDN), ont été mise en place par Google pour relier ses principaux datacenters [1], au travers le monde.Dans le cadre de ce projet, nous présentons une nouvelle architecture basée sur les concepts du SDN, pour les réseaux avec ou sans infrastructure. Cette architecture est composée de réseaux filaires, sans fil et ad-hoc. Elle est ensuite proposée pour intégrer des objets communicants dans un domaine du réseau SDN. Différents domaines sont alors interconnectés pour que la gestion du réseau soit distribuée, sans toutefois réduire le niveau de sécurité. Cette étude propose une nouvelle architecture sécurisée et distribuée pour l'IoT (Internet des Objets). / Recently, the giants of the Internet are adopting every day more and more the benefits of virtualization within the data center. Each virtualized application and its operating system can run simultaneously from one physical device. This technology reduces significantly power consumption, energy consumption, as well as operational cost. Furthermore, not long ago, this promising solution is studied by the research communities to be extended for network virtualization deployment. In traditional network physical device like routers and/or switches are responsible to transfer the information from one point to another, following the instructions previously programmed by a network administrator. At this time, the physical networking devices can be virtualized, providing an intelligent abstraction via virtual network software that makes easy to deploy and manage network resources. The search giant Google has deployed SDN to experiment with the inter-connection between their data center around the world [1].With the exponential growth of devices connected to the Internet, security network is one of the hardest challenge for network managers. Maintaining and securing such large scale and heterogeneous network is a challenging task. In this context, the new networking paradigm, the Software Defined Networking (SDN), introduces many opportunities and provides the potential to overcome those challenges. In our approach, we first propose a new SDN based architecture for networking with or without infrastructure, that we call an SDN domain. This domain includes wired network, wireless network and Ad-Hoc networks. Next, a second architecture includes sensor networks in an SDN-based network and in a domain. Third, interconnecting multiple domains and we describe how we can enhance the security of each domain and how to distribute the security rules in order not to compromise the security of one domain. Finally, we present a new secure and distributed architecture for ad-hoc networks and IoT (Internet of Things).

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