In future, Mobile Ad Hoc Networks (MANETs) may provide access to services in the Internet. MANETs should therefore support diverse applications and data types. This introduces a need for quality of service (QoS), a process of discriminating different data types to provide them with an appropriate level of service. However, QoS can be affected by nodes performing packet forwarding attacks. A critical analysis of the related literature shows that research into QoS and security has typically proceeded independently. However, QoS and security should be considered together as attacks may adversely affect QoS. A simulation study demonstrates this by investigating two single-path packet forwarding approaches under a range of conditions. The study shows that using single-path packet forwarding in the presence of attackers is generally insufficient to support QoS.Based on this background research, a novel 2-Dimensional Adaptation ARChitecture (2-DAARC) and a Priority-based Multi-path Type Selection (PMTS) algorithm are proposed. 2-DAARC integrates two modes of adaptation. The single-path adaptation (SPA) mode uses adaptive bandwidth reservations over a single path for QoS in the presence of node mobility. The multi-path adaptation (MPA) mode uses duplicated data packet transmissions over multiple paths for QoS in the presence of packet forwarding attackers. Adaptation occurs within and between modes to optimize priority packet forwarding in the dynamic MANET environment. The MPA mode uses the PMTS algorithm to select a secondary path which is maximally-disjoint with the primary path. This aims to select a path which may enhance reliability whilst keeping the costs of path selection low. Simulating 2-DAARC shows that under light loads it achieves better QoS than related work, but with a higher control packet overhead. Simulating PMTS shows that under light loads it achieves packet deliveries which are at best as good as a related approach, with lower end-to-end delays and control packet overhead. A novel Congestion and ATtack (CAT) detection mechanism is proposed to improve the performance of 2-DAARC in heavily loaded networks. CAT detection differentiates the causes of packet loss so that adaptation can be better tailored to the network conditions. Without CAT detection, 2-DAARC uses the MPA mode in congested conditions, and this worsens QoS. Simulating 2-DAARC with CAT detection shows that it generally achieves packet deliveries which are greater than or similar to, and end-to-end delays which are less than or similar to related work, and it does so with a lower control packet overhead.

Esta tesis nos ha permitido trasladar algunos conceptos teóricos de la computación ubicua a escenarios reales, identificando las necesidades específicas de diferentes tipos de aplicaciones. Con el fin de alcanzar este objetivo, proponemos dos prototipos que proporcionan servicios sensibles al contexto en diferentes entornos, tales como conferencias o salas de recuperación en hospitales. Estos prototipos experimentales explotan la tecnología Bluetooth para ofrecer información basada en las preferencias del usuario. En ambos casos, hemos llevado a cabo algunos experimentos con el fin de evaluar el comportamiento de los sistemas y su rendimento. También abordamos en esta tesis el problema de la autoconfiguración de redes MANET basadas en el estándar 802.11 a través de dos soluciones novedosas. La primera es una solución centralizada que se basa en la tecnología Bluetooth, mientras la segunda es una solución distribuida que no necesita recurrir a ninguna tecnología adicional, ya que se basa en el uso del parámetro SSID. Ambos métodos se han diseñado para permitir que usuarios no expertos puedan unirse a una red MANET de forma transparente, proporcionando una configuración automática, rápida, y fiable de los terminales. Los resultados experimentales en implementaciones reales nos han permitido evaluar el rendimiento de las soluciones propuestas y demostrar que las estaciones cercanas se pueden configurar en pocos segundos. Además, hemos comparado ambas soluciones entre sí para poner de manifiesto las diferentes ventajas y desventajas en cuanto a rendimento. La principal contribución de esta tesis es EasyMANET, una plataforma ampliable y configurable cuyo objetivo es automatizar lo máximo posible las tareas que afectan a la configuración y puesta en marcha de redes MANET, de modo que su uso sea más simple y accesible. / Cano Reyes, J. (2012). Integrated Architecture for Configuration and Service Management in MANET Environments [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/14675 / Palancia

Although smart mobile devices have only come into prominence recently, they have quickly become a necessity in the modern world. In 2012, more than 450 million new smartphones are expected to be purchased around the world, exceeding, for the first time, purchases of laptops and desktop PCs combined in a single year. That, in addition to the increasing processing power and low cost of these emerging mobile devices, creates an increasing demand for mobile applications that work in infrastructure-supported environments like WiFi and cellular networks as well as infrastructure-less environments like ad hoc networks. Therefore, the behavior of mobile devices in such scenarios should be a continued focus of research. Several factors contribute to the observed behavior of nodes in Mobile Ad-hoc Networks MANETs. For example, nodes may act selfishly to preserve their limited energy resources. This selfishness may be detrimental to network performance. Therefore, cooperation between peers is necessary to keep these MANETs operational. Beside the need for actively encouraging cooperation by providing incentives, passive encouragement is also needed to overcome the effect of factors that limit cooperation, including malicious behavior, environmental obstruction, and mobility. The contribution of this work is to provide a cooperation model in MANETs that is capable of surviving topology distortions caused by mobility, and is operable in practical distributed scenarios. Towards this goal, we first provide a study of the topology characteristics of MANETs based on real experiments. We study the node degree, link stability, and link symmetry of these networks, and, based on our observations, we suggest a two-state Markov model to model link state in such networks, demonstrating the superiority of this model over the widely-used disk model with mobility. We conclude from this study that both mobility and channel fluctuations have a significant influence on the network topology, which makes it important to study cooperation in scenarios where the topology is changing rapidly. Based on experimental observations of a real network, we propose a coalition game model for cooperation in MANETs that shows that stable, effective coalitions can be maintained, even in the face of a dynamic network topology. We provide an initial evaluation of the model using a centralized simulation approach. We use the notion of reachability to evaluate the proposed model, and we simulate the model under different speeds and node densities. Our simulations show that reachability can be sustained at stable levels despite the deterioration caused by mobility. In addition, we show that our cumulative coalition formation approach gives good results in terms of reachability level and computational complexity. We also show that our proposed model achieves a fair payoff distribution among participating nodes. Motivated by the promising results of our centralized simulation approach, we take a further step towards more practical evaluation. We integrate the cooperation model with an existing MANET routing protocol, OLSR, and evaluate it in this distributed environment. We modify and augment the OLSR messaging mechanism to enable the exchange of the coalition information required to keep the model operating. Beside ensuring that the reachability gain is still attained and the coalition structure is stable, we study the effect of the extra control traffic overhead incurred by the model. We compare deliverability over the network with and without the cooperation model. Although our results show that the cooperation model incurs an average overhead exceeding $100\%$ of that incurred by OLSR in high density scenarios, it shows better reliability in delivering traffic especially among selfish nodes in low and average density scenarios. Counter to what is commonly assumed in the literature, this study shows that cooperation can be be maintained in a distributed manner without causing significant traffic overhead to MANETs run by proactive routing protocols. Due to the simplicity, several extensions can be applied to enhance the performance of the proposed model and diversify its usage. We propose these extensions at the end of this dissertation. / Ph. D.

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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

Mobile Ad hoc Network (MANET) routing protocols are designed to provide connectivity between wireless mobile nodes that do not have access to high-speed backbone networks. While many unicast MANET protocols have been explored, research involving multicast protocols has been limited. Existing multicast algorithms attempt to reduce routing overhead, but few, if any, attempt to reduce data overhead. The broadcast nature of wireless communication creates a unique environment in which overlaps in coverage are common. When designed properly, a multicast algorithm can take advantage of these overlaps and reduce data overhead. Unlike a unicast route, in which there is one path between a sender and receiver, a multicast tree can have multiple branches between the sender and its multiple receivers. Some of these paths can be combined to reduce redundant data rebroadcasts. The extensions presented in this thesis are a combination of existing and original routing techniques that were designed to reduce data rebroadcasts by aggregating multicast data flows. One such optimization takes advantage of the multipoint relay (MPR) nodes used by the Optimized Link State Routing (OLSR) unicast protocol. These nodes are used in unicast routing to reduce network broadcast, but can be used to help create efficient multicast data flows. Additionally, by listening to routing messages meant for other nodes, a host can learn a bit about its network and may be able to make routing changes that improve the multicast tree. This protocol was implemented as a software router in Linux. It should be emphasized that this is a real implementation and not a simulation. Experiments showed that the number of data packets in the network could be reduced by as much as 19 percent. These improvements were accomplished while using only a small amount of routing overhead. / Master of Science

A mobile ad hoc network (MANET) is formed by a collection of self-organizing nodes. Such networks are being deployed in a variety of environments, for example to provide mission-critical services in times of crises. Nodes participating in a MANET tend to have limited energy and computing resources and depend on various network-based resources to operate as a cohesive system. The same features such as dynamic and adaptive network topologies that make MANETs powerful also make the discovery and operation of network services a challenge. This thesis presents the design and implementation of an extensible information dissemination scheme that is integrated with the Optimized Link State Routing (OLSR) protocol to address the challenges of service discovery in mobile ad hoc networks. The thesis presents a detailed design of the information dissemination scheme based on the Naval Research Laboratory's (NRL) ProtoLib network protocol programming framework. In the proposed scheme, a solution that separates the routing process from the NRL OLSR routing protocol was designed, thus making OLSR a topology discovery protocol. This can further facilitate the implementation of various routing algorithms based on other metrics, such as the signal-to-noise ratio (SNR) of wireless links or the nodes' level of cooperation, when forwarding messages in the network. Additionally, a reusable event-driven programming interface to the NRL OLSR routing protocol was designed and implemented in this research. Events are triggered based on changes in the network topology. This programming interface can be used by other management and monitoring clients on the network for receiving real-time updates about link and topology changes as seen by OLSR. A priority message delivery scheme was developed that provides different quality of service (QoS) levels for information dissemination in mobile ad hoc networks. To ensure a fair use of the transport media and support various message sizes, a message fragmentation solution was implemented. The proposed information dissemination solution was then deployed in a real wireless ad-hoc environment for further validation and testing. Using experiments with six nodes and various test scenarios, this research verified the functionality and characterized the performance of the proposed system. It was observed that the link-state nature of information dissemination solution helped it to adapt to topology changes. It was also realized that service discovery latency after information convergence in the network was independent of the number of nodes between the service providers and clients. The experiments also confirmed that the immediate message delivery scheme provides superior quality of service to registered users in presence of radio interference and other delays caused by Multipoint Relay Nodes (MPR) message forwarding in OLSR. / Master of Science

In this thesis, we are concerned with content dissemination in mobile ad hoc networks. The scope of content dissemination is limited by network capacity, and sometimes the price to be paid for securing faster delivery. In the first part of the thesis, we address the issue of finding the maximum throughput that a mobile ad-hoc network can support. We have assumed that there is no price involved, and all nodes work as a team. The problem of determining the capacity region has long been known to be NP-hard even for stationary nodes. Mobility introduces an additional dimension of complexity because nodes now also have to decide when they should initiate route discovery. Since route discovery involves communication and computation overhead, it should not be invoked very often. On the other hand, mobility implies that routes are bound to become stale, resulting in sub-optimal performance if routes are not updated. We attempt to gain some understanding of these effects by considering a simple one-dimensional network model. The simplicity of our model allows us to use stochastic dynamic programming (SDP) to find the maximum possible network throughput with ideal routing and medium access control (MAC) scheduling. Using the optimal value as a benchmark, we also propose and evaluate the performance of a simple threshold-based heuristic. Unlike the optimal policy which requires considerable state information, the proposed heuristic is simple to implement and is not overly sensitive to the threshold value. We find empirical conditions for our heuristic to be near-optimal. Also, network scenarios when our heuristic does not perform very well are analyzed. We provide extensive numerical analysis and simulation results for different parameter settings of our model. Interestingly, we observe that in low density network the average throughput can first decrease with mobility, and then increase. This motivates us to study a mobile ad-hoc network when it is sparse and in a generalized environment, such as when movement of nodes is in a two-dimension plane. Due to sparseness, there are frequent disruptions in the connections and there may not be any end-to-end connection for delivery. The mobility of nodes may be used for carrying the forwarded message to the destination. This network is also known as a delay tolerant network. In the rest part of the thesis, we consider the relay nodes to be members of a group that charges a price for assisting in message transportation. First, we solve the problem of how to select first relay node when only one relay node can be chosen from a given number of groups. Next, we solve two problems, namely price-constrained delay minimization, and delay-constrained price optimization.