21 research outputs found

    FPGA-based wireless link emulator for wireless sensor network

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    Energy Effective Routing Protocol for Maximizing Network Lifetime of WSN

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    ABSTRACT: Efficiency is the keynote factor going to be addressed in this paper. Considering the fact that there are relatively very few wireless sensor networks and hardly any efficient ones, EMBA (Efficient Multihop Broadcast Asynchronous), a duty-scheduled asynchronous wireless sensor networks is being proposed that carries the ability to wake up according to its own schedule. This is accomplished by the forwarders' guidance and the overhearing of broadcast messages and ACK. A forwarders' guidance is when a node transmits broadcast messages to its neighbour nodes by using unicast transmissions thereby reducing redundant transmissions and arising collisions. The active time of nodes is considerably decreased by the overhearing of broadcast messages and ACKs by keeping a thorough check on the number of transmissions and reducing them. In this paper, we put the EMBA and conventional protocols of ADB and RI-MAC broadcast to test in both sparse and dense networks. And, in the end, results exhibit that EMBA achieve a lower message cost due to higher efficiency and lower energy consumption than the conventional protocols

    Self-Synchronization in Duty-cycled Internet of Things (IoT) Applications

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    In recent years, the networks of low-power devices have gained popularity. Typically these devices are wireless and interact to form large networks such as the Machine to Machine (M2M) networks, Internet of Things (IoT), Wearable Computing, and Wireless Sensor Networks. The collaboration among these devices is a key to achieving the full potential of these networks. A major problem in this field is to guarantee robust communication between elements while keeping the whole network energy efficient. In this paper, we introduce an extended and improved emergent broadcast slot (EBS) scheme, which facilitates collaboration for robust communication and is energy efficient. In the EBS, nodes communication unit remains in sleeping mode and are awake just to communicate. The EBS scheme is fully decentralized, that is, nodes coordinate their wake-up window in partially overlapped manner within each duty-cycle to avoid message collisions. We show the theoretical convergence behavior of the scheme, which is confirmed through real test-bed experimentation.Comment: 12 Pages, 11 Figures, Journa

    Wireless Cyber-Physical Simulator and Case Studies on Structural Control

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    Abstract: Wireless Structural Control (WSC) systems can play a crucial role in protecting civil infrastructure in the event of earthquakes and other natural disasters. Such systems represent an exemplary class of cyber-physical systems that perform close-loop control using wireless sensor networks. Existing WSC research usually employs wireless sensors installed on small lab structures, which cannot capture realistic delays and data loss in wireless sensor networks deployed on large civil structures. The lack of realistic tools that capture both the cyber (wireless) and physical (structural) aspects of WSC systems has been a hurdle for cyber-physical systems research for civil infrastructure. This advances the state of the art through the following contributions. First, we developed the Wireless Cyber-Physical Simulator (WCPS), an integrated environment that combines realistic simulations of both wireless sensor networks and structures. WCPS integrates Simulink and TOSSIM, a state-of-the-art sensor network simulator featuring a realistic wireless model seeded by signal traces. Second, we performed two realistic case studies each combining a structural model with wireless traces collected from real-world environments. The building study combines a benchmark building model and wireless traces collected from a multi-story building. The bridge study combines the structural model of the Cape Girardea

    Self-Adapting MAC Layer for Wireless Sensor Networks

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    The integration of wireless sensors with mobile phones is gaining momentum as an enabling platform for numerous emerging applications. These mobile systems face dynamic environments where both application requirements and ambient wireless conditions change frequently. Despite the existence of many MAC protocols however, none can provide optimal performance along multiple dimensions, in particular when the conditions are frequently changing. Instead of pursuing a one-MAC-fit all approach we present a Self-Adapting MAC Layer (SAML) comprising (1) a Reconfigurable MAC Architecture (RMA) that can switch to different MAC protocols at run time and (2) a learning-based MAC Selection Engine that selects the protocol most suitable for the current condition and requirements. As the ambient conditions or application requirements change SAML dynamically switches MAC protocols to gain the desired performance. To the application SAML appears as a traditional MAC protocol and its benefits are realized without troubling the application with the underlying complexity. To test the system we implement SAML in TinyOS 2.x and realize three prototypes containing up to five MACs. We evaluate the system in controlled tests and real-world environments using a new gateway device that integrates a 802.15.4 radio with Android phones. Our experimental results show that SAML provides an efficient and reliable MAC switching, while adheres to the application specified requirements

    EcoPlex: Empowering compact wireless sensor platforms via roaming and interoperability support

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    Abstract—EcoPlex is an infrastructure that enables simple wireless platforms to participate seamlessly in a feature-rich, wireless ad hoc network. EcoPlex consists of gateways that are responsible for handoff support for mobility and high data rate without burdening the simple nodes to implement multi-hop protocols. The gateways also create virtual identities for simpler nodes to enable their participation in the feature-rich network without adding complexity to them. We demonstrate the feasibility of this idea with the ultra-compact wireless sensor platform called Eco to participate as virtual nodes in a fully general ZigBee network. Experimental results show EcoPlex to be efficient and scalable. The enhanced mobility and interoperability are added to the Eco platform at the infrastructure level, all with minimal node complexity. I

    Machine Learning in Wireless Sensor Networks: Algorithms, Strategies, and Applications

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    Wireless sensor networks monitor dynamic environments that change rapidly over time. This dynamic behavior is either caused by external factors or initiated by the system designers themselves. To adapt to such conditions, sensor networks often adopt machine learning techniques to eliminate the need for unnecessary redesign. Machine learning also inspires many practical solutions that maximize resource utilization and prolong the lifespan of the network. In this paper, we present an extensive literature review over the period 2002-2013 of machine learning methods that were used to address common issues in wireless sensor networks (WSNs). The advantages and disadvantages of each proposed algorithm are evaluated against the corresponding problem. We also provide a comparative guide to aid WSN designers in developing suitable machine learning solutions for their specific application challenges.Comment: Accepted for publication in IEEE Communications Surveys and Tutorial

    Evaluation and Comparison of MAC Protocols in Wireless Sensor Networks

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    Wireless sensor network applications call for different kinds of network protocols at different levels of the network stack based on application requirements. A number of medium access control (MAC) protocols have been proposed in the literature. Evaluation of most of these MAC protocols have typically been based on simulation, and while such simulation provides interesting insight into the behavior of these protocols, artifacts caused by behavior of hardware is ignored. Further more, MAC protocols are usually evaluated by comparing the new protocol with others based on one or two metrics, the ones that determined the design decisions for the protocol under evaluation. In this thesis, we present a comprehensive evaluation of MAC protocols based on a set of common metrics. The evaluation is conducted by way of experiments on a test bed of real sensor hardware for different scenarios and work loads that would match different application requirement
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