4,539 research outputs found

    Identifying Design Requirements for Wireless Routing Link Metrics

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    In this paper, we identify and analyze the requirements to design a new routing link metric for wireless multihop networks. Considering these requirements, when a link metric is proposed, then both the design and implementation of the link metric with a routing protocol become easy. Secondly, the underlying network issues can easily be tackled. Thirdly, an appreciable performance of the network is guaranteed. Along with the existing implementation of three link metrics Expected Transmission Count (ETX), Minimum Delay (MD), and Minimum Loss (ML), we implement inverse ETX; invETX with Optimized Link State Routing (OLSR) using NS-2.34. The simulation results show that how the computational burden of a metric degrades the performance of the respective protocol and how a metric has to trade-off between different performance parameters

    An Adaptive Fault-Tolerant Communication Scheme for Body Sensor Networks

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    A high degree of reliability for critical data transmission is required in body sensor networks (BSNs). However, BSNs are usually vulnerable to channel impairments due to body fading effect and RF interference, which may potentially cause data transmission to be unreliable. In this paper, an adaptive and flexible fault-tolerant communication scheme for BSNs, namely AFTCS, is proposed. AFTCS adopts a channel bandwidth reservation strategy to provide reliable data transmission when channel impairments occur. In order to fulfill the reliability requirements of critical sensors, fault-tolerant priority and queue are employed to adaptively adjust the channel bandwidth allocation. Simulation results show that AFTCS can alleviate the effect of channel impairments, while yielding lower packet loss rate and latency for critical sensors at runtime.Comment: 10 figures, 19 page

    Software Defined Networks based Smart Grid Communication: A Comprehensive Survey

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    The current power grid is no longer a feasible solution due to ever-increasing user demand of electricity, old infrastructure, and reliability issues and thus require transformation to a better grid a.k.a., smart grid (SG). The key features that distinguish SG from the conventional electrical power grid are its capability to perform two-way communication, demand side management, and real time pricing. Despite all these advantages that SG will bring, there are certain issues which are specific to SG communication system. For instance, network management of current SG systems is complex, time consuming, and done manually. Moreover, SG communication (SGC) system is built on different vendor specific devices and protocols. Therefore, the current SG systems are not protocol independent, thus leading to interoperability issue. Software defined network (SDN) has been proposed to monitor and manage the communication networks globally. This article serves as a comprehensive survey on SDN-based SGC. In this article, we first discuss taxonomy of advantages of SDNbased SGC.We then discuss SDN-based SGC architectures, along with case studies. Our article provides an in-depth discussion on routing schemes for SDN-based SGC. We also provide detailed survey of security and privacy schemes applied to SDN-based SGC. We furthermore present challenges, open issues, and future research directions related to SDN-based SGC.Comment: Accepte

    Modeling and Analysis of Fault Tolerant Multistage Interconnection Networks

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    Performance and reliability are two of the most crucial issues in today\u27s high-performance instrumentation and measurement systems. High speed and compact density multistage interconnection networks (MINs) are widely-used subsystems in different applications. New performance models are proposed to evaluate a novel fault tolerant MIN arrangement, thereby assuring performance and reliability with high confidence level. A concurrent fault detection and recovery scheme for MINs is considered by rerouting over redundant interconnection links under stringent real-time constraints for digital instrumentation as sensor networks. A switch architecture for concurrent testing and diagnosis is proposed. New performance models are developed and used to evaluate the compound effect of fault tolerant operation (inclusive of testing, diagnosis, and recovery) on the overall throughput and delay. Results are shown for single transient and permanent stuck-at faults on links and storage units in the switching elements. It is shown that performance degradation due to fault tolerance is graceful while performance degradation without fault recovery is unacceptable
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