57 research outputs found

    A Protocol for Supporting Context Provision in Wireless Mobile Ad Hoc Networks

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    The increasing ubiquity of mobile computing devices has made ad hoc networks everyday occurrences. In these highly dynamic environments, the multitude of devices provides a varied and rapidly changing environment in which applications must learn to operate. Successful end-user applications will not only learn to function in this environment but will take advantage of the variety of information available. Protocols for gathering an applicationā€™s contextual information must be built into the network to function in a timely and adaptive fashion. This paper presents a protocol for providing context information to such applications. We present an implementation and show how it provides context information to mobile applications in an on-demand manner. We also provide a simulation analysis of the tradeoļ¬€s between consistency and range of context deļ¬nitions in highly dynamic ad hoc networks

    Byzantine modification detection in multicast networks using randomized network coding

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    Distributed randomized network coding, a robust approach to multicasting in distributed network settings, can be extended to provide Byzantine modification detection without the use of cryptographic functions is presented in this paper

    MADServer: An Architecture for Opportunistic Mobile Advanced Delivery

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    Rapid increases in cellular data traffic demand creative alternative delivery vectors for data. Despite the conceptual attractiveness of mobile data offloading, no concrete web server architectures integrate intelligent offloading in a production-ready and easily deployable manner without relying on vast infrastructural changes to carriersā€™ networks. Delay-tolerant networking technology offers the means to do just this. We introduce MADServer, a novel DTN-based architecture for mobile data offloading that splits web con- tent among multiple independent delivery vectors based on user and data context. It enables intelligent data offload- ing, caching, and querying solutions which can be incorporated in a manner that still satisfies user expectations for timely delivery. At the same time, it allows for users who have poor or expensive connections to the cellular network to leverage multi-hop opportunistic routing to send and receive data. We also present a preliminary implementation of MADServer and provide real-world performance evaluations

    Autonomous Gossiping: A self-organizing epidemic algorithm for selective information dissemination in mobile ad-hoc networks

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    We introduce autonomous gossiping (A/G), a new genre epidemic algorithm for selective dissemination of information in contrast to previous usage of epidemic algorithms which flood the whole network. A/G is a paradigm which suits well in a mobile ad-hoc networking (MANET) environment because it does not require any infrastructure or middleware like multicast tree and (un)subscription maintenance for publish/subscribe, but uses ecological and economic principles in a self-organizing manner in order to achieve its selectivity. The trade-off of using an infrastructure-less self-organizing mechanism like A/G is that it does not guarantee completeness deterministically as is one of the original objectives of alternate selective dissemination schemes like publish/subscribe. We argue that such incompleteness is not a problem in many non-critical real-life civilian application scenarios and realistic node mobility patterns, where the overhead of infrastructure maintenance may outweigh the benefits of completeness, more over, at present there exists no mechanism to realize publish/subscribe or other paradigms for selective dissemination in MANET environments. A/G's reliance and hence vulnerability on cooperation of mobile nodes is also much less as compared to other possible schemes using routing information, since it does not expect node philanthropy for forwarding/carrying information, but only cooperation to the extent that nodes already carrying the information pass it on to other suitable ones. Thus autonomous gossiping is expected to be a light-weight infrastructure-less information dissemination service for MANETs, and hence support any-to-many communication (flexible casting) without the need to establish and maintain separate routing information (e.g., multicast trees)

    A Mobile Ad Hoc Network Routing Protocols: A Comparative Study

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    Mobile Ad hoc NETworks (MANET), are complex and distributed networks that are dynamic. Which are infrastructure less and multi-hop in nature. The communication of a node can be either direct or through intermediate nodes without a fixed and dedicated infrastructure. Hence it is necessary to design an efficient routing protocol for ad hoc network which can address the issues of MANET efficiently. In ad hoc, routing algorithms are classified into nine categories namely: source-initiated (reactive), table-driven (proactive), hybrid, hierarchical, multipath, multicast, location-aware, geographical-multicast and power-aware. This paper presents a survey and to review a comparative study about various routing protocols under each of these categories. Additionally, brief discussions about major routing issues are addressed. This survey paper focuses on the taxonomy related to ad hoc routing techniques and compares the features of routing protocols

    Recent Trends in Communication Networks

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    In recent years there has been many developments in communication technology. This has greatly enhanced the computing power of small handheld resource-constrained mobile devices. Different generations of communication technology have evolved. This had led to new research for communication of large volumes of data in different transmission media and the design of different communication protocols. Another direction of research concerns the secure and error-free communication between the sender and receiver despite the risk of the presence of an eavesdropper. For the communication requirement of a huge amount of multimedia streaming data, a lot of research has been carried out in the design of proper overlay networks. The book addresses new research techniques that have evolved to handle these challenges

    FAR: Face-Aware Routing for Mobicast in Large-Scale Sensor Networks

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    This paper presents FAR, a Face-Aware Routing protocol for mobicast, a spatiotemporal variant of multicast tailored for sensor networks with environmental mobility. FAR features face-routing and timed-forwarding for delivering a message to a mobile delivery zone. Both analytical and statistical results show that, FAR achieves reliable and just-in-time mes-sage delivery with only moderate communication and memory overhead. This paper also presents a novel distributed algorithm for spatial neighborhood discovery for FAR boot-strapping. The spatiotemporal performance and reliability of FAR are demonstrated via ns-2 simulations

    A Survey of Applying Ad Hoc Wireless Sensor Actuator Networks to Enhance Context-Awareness in Environmental Management Systems

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    Sensor mesh networking is set to be one of the key tools for the future of Ambient Intelligence (AmI) due to new emerging technologies in Ad hoc Wireless Sensor Networks (AWSNs). AWSNs symbolize the new generation of sensor networks with many promising advantages applicable to most networked environments. Unfortunately, however, these practical technologies have some technical problems and, as a consequence, this fascinating field has created novel and interesting challenges, which in turn, have inspired many ongoing research projects and more are likely to follow. Almost certainly, there will be notable improvements in the management of control/actuator networks as a consequence of enhancing the sensitivity capabilities of systems. With an emphasis on Ad hoc Wireless Sensor Actuator Networks (AWSANs) this study presents a systematic analysis of the different existing techniques to improve such systems. It also discusses, analyzes and summarizes the advantages these technologies offer in certain applications and presents a generic solution, in the form of a case study, for an AmI system to enhance the overall environmental management of a campus based on a hierarchical network using an AWSAN
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