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This thesis describes the Flexible Internetwork Stack (FINS) Framework, an open-source tool to facilitate experimental research in wireless networks on multiple platforms. The FINS Framework uses a module-based architecture that allows cross-layer behavior and runtime reconfiguration of the protocol stack. Version 1.0 of the framework makes use of existing physical and data link layer functionality, while enabling modifications to the stack at the network layer and above, or even the implementation of a clean-slate, non-layered protocol architecture. Protocols, stubs for communicating with intact layers, and management and supervisory functions are implemented as FINS Framework modules, interconnected by a central switch. This thesis describes the FINS Framework architecture, presents an initial assessment along with experiments on Android and Ubuntu enabled by the tool, and documents an intuitive mechanism for transparently intercepting socket calls that maintains efficiency and flexibility. / Master of Science

Prior research in routing for wireless ad hoc networks has shown that multipath routing can enhance data delivery reliability and provide load balancing. Nevertheless, only a few multipath routing algorithms have been proposed and their interaction with transport layer protocols has not been thoroughly addressed in the literature. In this work, we propose the multipath “Fresnel zone” routing (FZR) algorithm for wireless ad hoc networks. FZR constructs multiple parallel paths from source to destination based on the concept of “Fresnel zones” in a wireless network. The zone construction method assigns intermediate routers into different “Fresnel zones” according to their capacity and efficiency in forwarding traffic. The central idea in FZR is to disperse traffic to different zones according to network load and congestion conditions, thus achieving better throughput and avoiding congestion at intermediate routers. FZR differs from most existing multipath routing approaches in that both source and intermediate nodes use multiple forwarding paths. FZR also adopts a combination of proactive and on-demand (reactive) approaches to reduce control overhead and latency for packet delivery. Simulation experiments have shown that FZR outperforms unipath distance vector routing, multipath distance vector (MDV) routing, and split multipath routing (SMR) algorithms in quasistatic wireless ad hoc networks. In our simulations, FZR achieves up to 100 percent higher average throughput using the User Datagram Protocol (UDP) and 50 percent higher average throughput using the Transmission Control Protocol (TCP). FZR can also provide better load balancing among different paths, improve network resource utilization, and enable fairer resource allocation among different data transmission sessions. Future work is needed to evaluate FZR in mobile scenarios. / Master of Science

A mobile ad hoc network is a collection of wireless nodes, all of which may be mobile, that dynamically create a wireless network amongst them without using any infrastructure. Ad hoc wireless networks come into being solely by peer-to-peer interactions among their constituent mobile nodes, and it is only such interactions that are used to provide the necessary control and administrative functions supporting such networks. Mobile hosts are no longer just end systems; each node must be able to function as a router as well to relay packets generated by other nodes. As the nodes move in and out of range with respect to other nodes, including those that are operating as routers, the resulting topology changes must somehow be communicated to all other nodes as appropriate. In accommodating the communication needs of the user applications, the limited bandwidth of wireless channels and their generally hostile transmission characteristics impose additional constraints on how much administrative and control information may be exchanged, and how often. Ensuring effective routing is one of the greatest challenges for ad hoc networking. As a practice, ad hoc routing protocols make routing decisions based on individual node mobility even for applications such as disaster recovery, battlefield combat, conference room interactions, and collaborative computing etc. that are shown to follow a pattern. In this thesis we propose an algorithm that performs routing based on underlying mobility patterns. A mobility pattern aware routing algorithm is shown to have several distinct advantages such as: a more precise view of the entire network topology as the nodes move; a more precise view of the location of the individual nodes; ability to predict with reasonably accuracy the future locations of nodes; ability to switch over to an alternate route before a link is disrupted due to node movements. / Master of Science

This research devises a unified method for the distribution of pseudonyms in hybrid ephemeral vehicular networks (VNs), which are often referred to as vehicular ad hoc networks (VANETs), for the purposes of refill, intra-regional, and inter-regional movement. This work addresses a significant impediment to the use of pseudonyms, which has been almost universally accepted (and is on the verge of being standardized by the Institute for Electrical and Electronic Engineers (IEEE) and the Society for Automotive Engineers (SAE) as the best means to balance attribution and privacy to maximize the value of infrastructure deployment and citizen acceptability (i.e. use). The results include a pseudonym distribution protocol that maximizes ease of use while not compromising the security or privacy pseudonyms afford. These results contribute to the solution, in a scalable, adaptive, and bandwidth efficient manner, one of the remaining impediments to the adoption of VANETs. The new method shows improved performance compared to a baseline pseudonym distribution method that does not take these factors into consideration.

As roadside and in-vehicle sensors are deployed under the Connected Vehicle Research program (formerly known as Vehicle Infrastructure Integration initiative and Intellidrive), an increasing variety of traffic data is becoming available in real time. This real time traffic data is shared among vehicles and between vehicles and traffic management centers through wireless communication. This course of events creates an opportunity for mobile computing and online traffic simulations. However, online traffic simulations require faster than real time running speed with high simulation resolution, since the purpose of the simulations is to provide immediate future traffic forecast based on real time traffic data. However, simulating at high resolution is often too computationally intensive to process a large scale network on a single processor in real time. To mitigate this limitation an online ad hoc distributed simulation with optimistic execution is proposed in this study. The objective of this study is to develop an online traffic simulation system based on an ad hoc distributed simulation with optimistic execution. In this system, data collection, processing, and simulations are performed in a distributed fashion. Each individual simulator models the current traffic conditions of its local vicinity focusing only on its area of interest, without modeling other less relevant areas. Collectively, a central server coordinates the overall simulations with an optimistic execution technique and provides a predictive model of traffic conditions in large areas by combining simulations geographically spread over large areas. This distributed approach increases computing capacity of the entire system and speed of execution. The proposed model manages the distributed network, synchronizes the predictions among simulators, and resolves simulation output conflicts. Proper feedback allows each simulator to have accurate input data and eventually produce predictions close to reality. Such a system could provide both more up-to-date and robust predictions than that offered by centralized simulations within a single transportation management center. As these systems evolve, the online traffic predictions can be used in surface transportation management and travelers will benefit from more accurate and reliable traffic forecast.

La croissance explosive des réseaux sans fil et l’augmentation du nombre de dispositifs sans fil ont soulevé de nombreuses difficultés techniques dans la planification et l’analyse de ces réseaux. Nous utilisons la modélisation continue, utile pour la phase initiale de déploiement et l’analyse à grande échelle des études régionales du réseau. Nous étudions le problème de routage dans les réseaux ad hoc, nous définissons deux principes d’optimisation du réseau: le problème de l’utilisateur et du système. Nous montrons que les conditions d’optimalité d’un problème d’optimisation construit d’une manière appropriée coïncide avec le principe de l’optimisation de l’utilisateur. Pour fonctions de coût différentes, nous résolvons le problème de routage pour les antennes directionnelles et omnidirectionnelles. Nous trouvons également une caractérisation des voies du coût minimum par l’utilisation extensive du Théorème de Green dans le cas d’antennes directionnelles. Dans de nombreux cas, la solution se caractérise par une équation aux dérivés partielles. Nous proposons l’analyse numérique par éléments finis qui donne les limites de la variation de la solution par rapport aux données. Lorsque nous permettons la mobilité des origines et destinations, on trouve la quantité optimale de relais actif. Dans les réseaux MIMO, nous montrons que, même lorsque la chaîne offre un nombre infini de degrés de liberté, la capacité est limitée par le rapport entre la taille du réseau d’antennes, la station de base, la position des mobiles et la longueur d’onde du signal. Nous constatons également l’association optimale mobile pour différentes politiques et distributions des utilisateurs. / The growing number of wireless devices and wireless systems present many challenges on the design and operation of these networks. We focus on massively dense ad hoc networks and cellular systems. We use the continuum modeling approach, useful for the initial phase of deployment and to analyze broad-scale regional studies of the network. We study the routing problem in massively dense ad hoc networks, and similar to the work of Nash, and Wardrop, we define two principles of network optimization: user- and system-optimization. We show that the optimality conditions of an appropriately constructed optimization problem coincides with the user-optimization principle. For different cost functions, we solve the routing problem for directional and omnidirectional antennas. We also find a characterization of the minimum cost paths by extensive use of Green’s theorem in directional antennas. In many cases, the solution is characterized by a partial differential equation. We propose its numerical analysis by finite elements method which gives bounds in the variation of the solution with respect to the data. When we allow mobility of the origin and destination nodes, we find the optimal quantity of active relay nodes. In Network MIMO systems and MIMO broadcast channels, we show that, even when the channel offers an infinite number of degrees of freedom, the capacity is limited by the ratio between the size of the antenna array at the base station and the mobile terminals position and the wavelength of the signal. We also find the optimal mobile association for the user- and system-optimization problem under different policies and distributions of the users.