In this work, we present a robust sensor fusion system for exploratory data collection, exploiting the spatial redundancy in sensor networks. Unlike prior work, our system design criteria considers a heterogeneous cor...
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ISBN:
(纸本)9783642136504
In this work, we present a robust sensor fusion system for exploratory data collection, exploiting the spatial redundancy in sensor networks. Unlike prior work, our system design criteria considers a heterogeneous correlated noise model and packet loss, but no prior knowledge of signal characteristics. the former two assumptions are both common signal degradation sources in sensor networks, while the latter allows exploratory data collection of unknown signals. through both a numerical example and an experimental study on a large military site, we show that our proposed system reduces the noise in an unknown signal by 58.2% better than a comparable algorithm.
Wireless sensor networks are often deployed in harsh environments, where the adversary is able to capture certain sensors. Once a sensor is compromised, the adversary can easily replicate it and deploy several replica...
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Wireless sensor networks are often deployed in harsh environments, where the adversary is able to capture certain sensors. Once a sensor is compromised, the adversary can easily replicate it and deploy several replicas back into the network for further malicious activities. Although a number of protocols have been proposed to tackle such node replication attacks, few of these schemes are suitable for mobile wireless sensor networks. In this paper, we propose two novel mobility-assisted distributed solutions to node replication detection in mobile wireless sensor networks. In both protocols, after receiving the time-location claims, witnesses carry these claims around the network instead of transmitting them. that means data are forwarded only when appropriate witnesses encounter each other. Unary-Time-Location Storage & Exchange (UTLSE) detects the replicas by each of the two encountered witnesses which stores only one time-location claim. Multi-Time-Location Storage & Diffusion (MTLSD), by storing more time-location claims for each tracked node and introducing time-location claims diffusion among witnesses, provides excellent resiliency and sub-optimal detection probability with modest communication overhead. Due to the mobility-assisted property, our protocols do not rely on any specific routing protocol, which makes them suitable for various mobile settings. Our theoretical analysis and simulation results show that our protocols are efficient in terms of detection performance, communication overhead and storage overhead.
Realizing energy efficient control strategies in the buildings is one of the innovative and challenging field of application for wireless sensor networks. To achieve the goal of reduced energy consumption and optimize...
Realizing energy efficient control strategies in the buildings is one of the innovative and challenging field of application for wireless sensor networks. To achieve the goal of reduced energy consumption and optimized use of energy in the buildings, the deployment of sensors and actuators is crucial. Simple affordable sensors can be used to monitor the power consumed by each appliance in the building in order to turn them on/off when it is efficient in the use of energy. the ARTEMIS Joint Undertaking project eDIANA (Embedded systems for Energy Efficient Buildings) funded by the European Commission aims to improve energy efficiency in buildings by using embedded technologies. In the eDIANA platform the energy consumed by household or office appliances is monitored by using ieee 802.15.4/Zigbee-compliant devices. the aim of the study is to show the feasibility of the ieee 802.15.4/Zigbee technology to the eDIANA application scenario and to provide guidelines for the network design. For this purpose two studies have been carried out: (i) a simulation analysis of a large apartment where many nodes are deployed; (ii) a real test-bed composed of ieee 802.15.4/ZigBee-compliant devices. In the first case performance, in terms of packet error rate, average delay and energy consumption, is evaluated by varying the number of nodes in different traffic conditions. In the second case, instead, the statistics of the delay is provided. the study shows that simulation results are in line withthe results achieved through the measurements. Moreover results fulfil the eDIANA requirements.
Large-scale distributed cyber-physical systems will have many sensors/actuators (each with local micro-controllers), and a distributed communication/computing backbone with multiple processors. Many cyber-physical app...
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ISBN:
(纸本)9781424472611
Large-scale distributed cyber-physical systems will have many sensors/actuators (each with local micro-controllers), and a distributed communication/computing backbone with multiple processors. Many cyber-physical applications will be safety-critical and in many cases unexpected workload spikes are likely to occur due to unpredictable changes in the physical environment. In the face of such overload scenarios, the desirable property in such systems is that the most critical applications continue to meet their deadlines. In this paper, we capture this mixed-criticality property by developing a formal overload-resilience metric called ductility. the generality of ductility enables it to evaluate any scheduling algorithm from the perspective of mixed-criticality cyber-physical systems. In distributed cyber-physical systems, this ductility is the result of boththe task-to-processor packing (a.k.a bin packing) and the uniprocessor scheduling algorithms used. In this paper, we present a ductility-maximization packing algorithm to complement our previous work on mixed-criticality uniprocessor scheduling [6]. Our packing algorithm, known as Compress-on-Overload Packing (COP) is a criticality-aware greedy bin-packing algorithm that maximizes the tolerance of high-criticality tasks to overloads. We compare the ductility of COP against the Worst-Fit Decreasing (WFD) bin-packing heuristic used traditionally for load balancing in distributedsystems, and show that the performance of COP dominates WFD in the average case and can reach close to five times better ductility when resources are limited. Finally, we illustrate the practical use of COP in distributed cyber-physical systems using a radar surveillance application, and provide an overview of the entire process from assigning task criticality levels to evaluating its performance.
We introduce DJ# - a language that can be used to program a Peer-to-Peer network using object-oriented techniques and Join methods. the object creation primitive of DJ# has two parameters, a class name and a peer name...
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We introduce DJ# - a language that can be used to program a Peer-to-Peer network using object-oriented techniques and Join methods. the object creation primitive of DJ# has two parameters, a class name and a peer name, allowing the programmer to create instances of any class on any node of the network. In the object-oriented programming spirit, DJ# objects can communicate by sending and receiving messages. As in Join Java or Polyphonic C#, both synchronous and asynchronous messages can be transmitted between distributed objects. the DJ# model provides a form of dynamic connectivity of interacting objects that can use Join methods to implement various communication mechanisms. the paper presents the design rationales and a formal operational semantics for DJ#.
In distributed WiMAX Mesh Networks (DWMN), a joint solution with FEBA (Fair End-to-end Bandwidth Allocation) and DRR (Deficit Round Robin) can be used to achieve high end-to-end throughput fairness. Even then, the hig...
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In distributed WiMAX Mesh Networks (DWMN), a joint solution with FEBA (Fair End-to-end Bandwidth Allocation) and DRR (Deficit Round Robin) can be used to achieve high end-to-end throughput fairness. Even then, the higher the number of hops a traffic flow traverses, the longer becomes the end-to-end delay of the traffic flow. this will result in serious unfairness of service quality among real-time traffic flows with different path length since they are delay-sensitive. In this paper, an improved fair scheduling mechanism based on the previous joint solution is proposed to deal withthe above-mentioned problem by assigning a greater scheduling weight to the relayed traffic flows. Moreover, a new fairness index is defined to evaluate the service quality fairness of traffic flows. the proposed mechanism is compared withthe previous joint solution by simulation. the results indicate that our proposed mechanism can provide better service quality fairness among real-time traffic flows without decreasing their throughput fairness. And it is also effective to improve the service quality fairness and throughput fairness of non-real-time traffic flows when the network is under a certain load.
Live monitoring of athletes during sporting events can help maximise performance while preventing injury, and enable new applications such as referee-assist and enhanced television broadcast services. A major challeng...
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Live monitoring of athletes during sporting events can help maximise performance while preventing injury, and enable new applications such as referee-assist and enhanced television broadcast services. A major challenge is the extraction of athlete physiological data in real-time, since the radio range of body-worn sensor devices is limited, necessitating multi-hop routing mechanisms. However, little is known about the highly dynamic operating conditions on a soccer field under which communication protocols need to operate. In this work we conduct field experiments in which we outfit first-division soccer players withsensor devices and record their inter-connectivity during a real game. Our first contribution profiles the key properties of the dynamic wireless topologies arising in the soccer field, and highlights the consequences for routing mechanisms. We show that the topology is in general sparse, with short encounters and power-law distributed inter-encounters. Importantly, the co-ordinated movement of players in the field gives rise to significant correlations amongst links, an aspect that can potentially be exploited by routing. Our second contribution develops a model for generating synthetic topologies that mirror connectivity in a real soccer game, and can be used for simulation studies of routing mechanisms. Its novelty lies in explicitly modelling the underlying auto-correlation and cross-correlation properties of the links, from which derived measures such as inter-encounter times and neighbourhood distributions follow. Our study is an important first step towards understanding and modelling dynamic topologies associated with sports monitoring, and paves the way for the design of real-time routing algorithms for such environments.
In this paper, the use of a centralized server to assist cognitive radio users in accessing bands in licensed spectrums is proposed. Typical cognitive radios are opportunistic users of spectrum bands. therefore, they ...
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In this paper, the use of a centralized server to assist cognitive radio users in accessing bands in licensed spectrums is proposed. Typical cognitive radios are opportunistic users of spectrum bands. therefore, they must scan the spectrum to detect existing users in order to avoid interference. the use of a centralized server can remove the need for spectrum scanning if all users inform the server about their presence. the server will coordinate and distribute channels to cognitive radio users using auctioning mechanisms. Our approach removes the need for cognitive radio users to spectrum scan. Scanning can be costly in terms of time and power consumption. In addition, collisions between users due to hidden node problem can be removed. the use of a centralized server allows for higher layer solution that would allow users of different wireless technologies to communicate. Due to its flexibility of use across different wireless networks, SIP is adopted as the communication protocol between the central server and the primary and secondary users of the licensed spectrum. Using a SIP server to coordinate channel allocation through auctioning approach can generate revenue for the incumbent network. Results show that revenue can be generated while still meeting the goal of efficient spectrum utilization.
Target tracking is a typical and important application of wireless sensor networks (WSNs). In the consideration of scalability and energy efficiency for target tracking in large scale WSNs, it has been employed as an ...
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ISBN:
(纸本)9783642136504
Target tracking is a typical and important application of wireless sensor networks (WSNs). In the consideration of scalability and energy efficiency for target tracking in large scale WSNs, it has been employed as an effective solution by organizing the WSNs into clusters. However, tracking a moving target in cluster-based WSNs suffers the boundary problem when the target moves across or along the boundary among clusters. In this paper, we propose a novel scheme, called hybrid cluster-based target tracking (HCTT), which integrates on-demand dynamic clustering into a cluster-based WSN for target tracking. To overcome the boundary problem, when the target moves close to the boundary among clusters, a dynamic cluster will be constructed for the management of target tracking. As the target moves, static clusters and on-demand dynamic clusters alternately manage the tracking task. Simulation results show that the proposed scheme performs better in tracking the moving target when compared with other typical target tracking protocols.
Most sensor network applications are dominated by the acquisition of sensor values. Due to energy limitations and high energy costs of communication, in-network processing has been proposed as a means to reduce data t...
ISBN:
(纸本)9783642136504
Most sensor network applications are dominated by the acquisition of sensor values. Due to energy limitations and high energy costs of communication, in-network processing has been proposed as a means to reduce data transfers. As application demands may change over time and nodes run low on energy, get overloaded, or simply face debasing communication capabilities, runtime adaptation is required. In either case, it is useful to be able to migrate computations between neighboring nodes without losing runtime state that might be costly or even impossible to recompute. We propose stateful mobile modules as a basic infrastructure building block to improve adaptiveness and robustness of in-network processing applications. Stateful mobile modules are binary modules linked on the node itself. Even more importantly, they can be transparently migrated from one node to another, thereby keeping statically as well as dynamically allocated memory. this is achieved by an optimized binary format, a memory-efficient linking process and an advanced programming support.
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