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Over the last decades, modeling of user mobility has become increasingly important in mobile networking research and development. This has led to the adoption of modeling techniques from other disciplines such as kinetic theory or urban planning. Yet these techniques generate movement behavior that is often perceived as not “realistic” for humans or provides only a macroscopic view on mobility. More recent approaches infer mobility models from real traces provided by positioning technologies or by the marks the mobile users leave in the wireless network. However, there is no common framework for assessing and comparing mobility models. In an attempt to provide a solid foundation for realistic mobility modeling in mobile networking research, we take an engineering approach and thoroughly discuss the required steps of model creation and validation. In this context, we survey how and to what extent existing mobility modeling approaches implement the proposed steps. This also summarizes helpful information for readers who do not want to develop a new model, but rather intend to choose among existing ones. [ABSTRACT FROM AUTHOR]

Recent debates over Internet policy have focused on the network's architecture. For example, the central justification for the Federal Communications Commission's Open Internet proceeding is that the Internet's architecture was critical to its past success and must be preserved. Unfortunately, policymakers and commentators have failed to provide any theoretical basis for determining whether any network configuration is optimal or when changed circumstances might justify a change to the architecture. The result is a regulatory approach that is unnecessarily static and reflexively accepting of the status quo, while failing to provide a basis for distinguishing between architectural changes that are part of the network's natural evolution and those that are potentially anticompetitive. This Article fills the void by providing an analytical framework for assessing network architecture based on modularity theory. It synthesizes modularity theory into five key concepts: near decomposition, interdependencies, abstraction/information hiding, requisite variety, and testing/integration. It then surfaces the tradeoffs inherent in the architectural decision by identifying the benefits and costs associated with modular architectures and analyzing the dynamics of architectural change. It concludes by using the framework to evaluate a series of recent policy applications, including the Telecommunications Act of 1996, network neutrality, the transition from IPv4 to IPv6, calls for opening the Apple iPhone's application programming interfaces ("API"s), and the evolution of future Internet architectures. An architectural approach based on modularity theory yields a number of important insights. It surfaces the inevitability of the tradeoff between generality and cost minimization and how generality can obstruct certain types of innovation. It underscores how parallel experimentation can accelerate innovation at the same time that the lack of coordination can stunt it. Moreover, like any design hierarchy, modular systems can resist technological change. Finally, it underscores the contingent nature of network architecture and provides heuristics for identifying when architectural change can be beneficial. [ABSTRACT FROM AUTHOR]

Recent years have witnessed the increasing efforts toward making architecture standardization for the secured wireless mobile ad hoc networks. In this scenario when a node actively utilizes the other node resources for communicating and refuses to help other nodes in their transmission or reception of data, it is called a selfish node. As the entire mobile ad hoc network (MANETs) depends on cooperation from neighboring nodes, it is very important to detect and eliminate selfish nodes from being part of the network. In this paper, token-based umpiring technique (TBUT) is proposed, where every node needs a token to participate in the network and the neighboring nodes act as umpire. This proposed TBUT is found to be very efficient with a reduced detection time and less overhead. The security analysis and experimental results have shown that TBUT is feasible for enhancing the security and network performance of real applications. [ABSTRACT FROM AUTHOR]

Opportunistic or delay-tolerant networks (DTNs) may be used to enable communication in case of failure or lack of infrastructure (disaster, censorship, remote areas) and to complement existing wireless technologies (cellular, WiFi). Wireless peers communicate when in contact, forming an impromptu network, whose connectivity graph is highly dynamic and only partly connected. In this harsh environment, communication algorithms are mostly local search heuristics, choosing a solution among the locally available ones. Furthermore, they are routinely evaluated through simulations only, as they are hard to model analytically. Even when more insight is sought from models, these usually assume homogeneous node meeting rates, thereby ignoring the attested heterogeneity and nontrivial structure of human mobility. We propose DTN-Meteo, a new unified analytical model that maps an important class of DTN optimization problems over heterogeneous mobility/contact models into a Markov chain traversal over the relevant solution space. (Heterogeneous) meeting probabilities between different pairs of nodes dictate the chain's transition probabilities and determine neighboring solutions. Local optimization algorithms can accept/reject candidate transitions (deterministically or randomly), thus “modulating” the above transition probabilities. We apply our model to two example problems: routing and content placement. We predict the performance of state-of-the-art algorithms (SimBet, BubbleRap) in various real and synthetic mobility scenarios and show that surprising precision can be achieved against simulations, despite the complexity of the problems and diversity of settings. To our best knowledge, this is the first analytical work that can accurately predict performance for utility-based algorithms and heterogeneous node contact rates. [ABSTRACT FROM PUBLISHER]

The need for an adaptive with support for context service aware Quality of Service routing scheme is always a major research challenge. The complexities of Mobile Ad hoc Networks are well surveyed, but traditional routing protocols do not focus on the context aware nature of services, which is highly required for dynamic change in service requirements. Context Aware Adaptive Fuzzy (COAAF) is a 'context aware' protocol, which is adaptive for variable services and network traffic intensity. The behaviour of streaming services is found to be highly variable; hence, fuzzy approach is adopted. COAAF is simulated over NS-2 and its performance analyzed in comparison with AODV, DYMO and GPSR routing schemes. [ABSTRACT FROM AUTHOR]