<p>In our homes and in the enterprise, in our leisure and in our professions, mobile computing is no longer merely "exciting;" it is becoming an essential, ubiquitous tool of the modern world. New and innovative mobile applications continue to inform, entertain, and surprise users. But, to make the daily use of mobile technologies more gratifying and worthwhile, we must move forward with new levels of sophistication. The Mobile App Stores of the future must be built on stronger foundations. </p><p>This dissertation considers a broad view of the challenges and intuitions behind a diverse selection of such new primitives. Some of these primitives will mitigate existing and fundamental challenges of mobile computing, especially relating to wireless communication. Others will take an application-driven approach, being designed to serve a novel purpose, and be adapted to the unique and varied challenges from their disparate domains. However, all are related through a unifying goal, to provide a seamless, enjoyable, and productive mobile experience. This dissertation takes view that by bringing together nontrivial enhancements across a selection of disparate-but-interrelated domains, the impact is synergistically stronger than the sum of each in isolation. Through their collective impact, these new "building blocks" can help lay a foundation to upgrade mobile technology beyond the expectations of early-adopters, and into seamless integration with all of our lives.</p> / Dissertation

Web browsing via Wi-Fi wireless access networks has become a basic function on a variety of consumer mobile electronic devices, such as smart phones, PDAs, and the Apple iPad. It has been found that in terms of energy consumption, wireless communications/networking plays an important role in mobile devices. Since the power-saving mode (PSM) of the IEEE 802.11 a/b/g standard is not tailored for the HTTP protocol, we propose a novel power saving scheme that exploits the characteristics of web applications. After sending HTTP requests, the proposed power saving scheme updates the estimated value of RTT based on the information contained in the TCP timestamp header field. Next, the proposed scheme adjusts the value of the listening period based on the estimated value of RTT. When all TCP connections have been closed, the wireless network card could enter the deep-sleeping mode. In this case, the value of the listening period could be larger than one second, since the user is reading the webpage and is unlikely to send another HTTP request within one second. The usage of the deep-sleeping mode can significantly reduce the power consumption of mobile devices.

The Distributed Coordination Function (DCF) which uses Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) and binary slotted exponential backoff scheme is the basis of the IEEE 802.11 Medium Access Control (MAC) protocol. However, the DCF is not suitable for real-time traffic control since the backoff scheme may cause huge frame delay and jitter. We propose a modified DCF which uses a forward backoff scheme to remedy this disadvantage. In addition, a call admission control (CAC) is also proposed. Our protocol can guarantee service qualities such as the network throughput, frame delay, and jitter for real-time traffics. Besides, the modified DCF is still compliant with the IEEE 802.11 standard. Simulation results have shown that our method performs better than other DCF disciplines.

Thèse de doctorat : Sciences informatiques : Paris Est : 2008. / Titre provenant de l'écran-titre.

Thèse doctorat : Télécommunications : Villeurbanne, INSA : 2007. / Titre provenant de l'écran-titre. Bibliogr. p. 180-192.

Thèse de doctorat : Automatique, Traitement du Signal et Génie Informatique : Nancy 1 : 2008. Thèse de doctorat : Automatique, Traitement du Signal et Génie Informatique : Ecole Nationale d'Ingénieurs de Sfax : 2008. / Thèse soutenue en co-tutelle. Titre provenant de l'écran-titre.

Thèse de doctorat : Informatique : Evry-Val d'Essonne : 2009. / Titre provenant de l'écran-titre.

Thesis (M.S. in Computer Science)--Naval Postgraduate School, March 2004. / Thesis advisor(s): Geoffrey Xie. Includes bibliographical references (p. 131-132). Also available online.

Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, March 2003. / Thesis advisor(s): Tri T. Ha, Jan E. Tighe. Includes bibliographical references (p. 105). Also available online.

Wireless networks are common in large organisations that can cover multiple floors and buildings. Wireless networks become expensive as they grow and more control and coordination is needed to operate and management them. This thesis describes how CloudMAC, a software defined networking solution (SDN), were implemented in OpenDaylight Hydrogen, a SDN controller. CloudMAC reduces complexity in large wireless local area networks. CloudMAC splits access points (AP) into, a physical (accesses the wireless medium) and a logical (handles the processing of data) part. These two part are then placed in different locations in a wired network. The parts are connected by making tunnels through the network. Some of the communications in wireless networks are time sensitive. Such time sensitive communication is easily disturbed during congestion. To improve CloudMAC, quality of service (QoS) was implemented. QoS was used both in the wired network and in accessing the wireless medium. Evaluations shows how to evaluate queues utilization and performance.