Available algorithms for the distributed construction of connected dominating sets in mobile ad hoc networks are inapplicable or suffer from a high complexity. This is mainly due to the resource-restricted nature of w...
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ISBN:
(纸本)9781457705137
Available algorithms for the distributed construction of connected dominating sets in mobile ad hoc networks are inapplicable or suffer from a high complexity. This is mainly due to the resource-restricted nature of wireless devices, such as sensor nodes, and the error-prone character of the communication medium. This work introduces and evaluates a new local, probabilistic self-stabilizing algorithm providing fault-tolerance and scalability for networks of high density.
Air pollution has become a major issue of modern megalopolis because of industrial emissions and increasing urbanization along with traffic jams and heating/cooling of buildings. Monitoring urban air quality is theref...
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ISBN:
(纸本)9781509014590
Air pollution has become a major issue of modern megalopolis because of industrial emissions and increasing urbanization along with traffic jams and heating/cooling of buildings. Monitoring urban air quality is therefore required by municipalities and by the civil society. Current monitoring systems rely on reference sensing stations that are precise but massive, costly and therefore seldom. In this ongoing work, we focus on an alternative or complementary approach, using a network of low cost and autonomic wireless sensors, allowing for a finer spatiotemporal granularity of air quality sensing. We tackle the optimization problem of sensor deployment and propose an integer programming model, which allows to find the optimal network topology while ensuring air quality monitoring with a high precision and the minimum financial cost. Most of existing deployment models of wireless sensor networks are generic and assume that sensors have a given detection range. This assumption does not fit pollutant concentrations sensing. Our model takes into account interpolation methods to place sensors in such a way that pollution concentration is estimated with a bounded error at locations where no sensor is deployed.
Self-stabilizing systems have in theory the unique and provable ability, to always return to a valid system state even in the face of failures. These properties are certainly desirable for domains like wireless ad-hoc...
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ISBN:
(纸本)9781509014590
Self-stabilizing systems have in theory the unique and provable ability, to always return to a valid system state even in the face of failures. These properties are certainly desirable for domains like wireless ad-hoc networks with numerous unpredictable faults. Unfortunately, the time in which the system returns to a valid state is not predictable and potentially unbound. The failure rate typically depends on physical phenomena and in self-stabilizing systems each node tries to react to failures in an inherently adaptive fashion by the cyclic observation of the states of its neighbors. When state changes are either too quick or too slow the system might never reach a state that is sufficiently stable for a specific task. In this paper, we investigate the influences of the error rate on the (stability) convergence time on the basis of topology information acquired in real network experiments. This allows us to asses the asymptotic behavior of relevant self-stabilizing algorithms in typical wireless networks.
Wireless sensor networks are often distributed which makes detection of cyber-attacks or misconfiguration hard. Topology and data patterns change may result from attacks leading to the compromise of data and service a...
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ISBN:
(纸本)9781665439299
Wireless sensor networks are often distributed which makes detection of cyber-attacks or misconfiguration hard. Topology and data patterns change may result from attacks leading to the compromise of data and service availability or indicate operational problems. Graphs are often used to model topology and data paths to describe and compare state of a system. For anomaly detection, the definition of normal patterns, deviation from normal, and criteria when to declare anomaly are required. In this contribution the process of acquisition of normal patterns (ground truth), and criteria when to declare anomaly based on graph comparison are proposed. The anomaly detection is suitable for deployment at the edge of a network. Finally, the inability to define all security threats is addressed by a custom tree-based classifier which only requires normal patterns for training. A simulated wireless sensor network was used to acquire data and apply the method. Our experiments show that data and topology change can be detected at the edge of a network.
Cyber-physical applications need to process a lot of sensor data, for example, to analyze traffic patterns and structural soundness of critical infrastructures. Although the amount of sensor data to process is increas...
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ISBN:
(纸本)9781424444465
Cyber-physical applications need to process a lot of sensor data, for example, to analyze traffic patterns and structural soundness of critical infrastructures. Although the amount of sensor data to process is increasing fast, system support to efficiently store and analyze an extensive amount of sensor data largely lags behind. To efficiently store, retrieve, and process massive sensor data, we are developing a sensor data center (SDC) that supports spatio-temporal sensor data structures and parallel sensor data processing using clustered computational nodes composed of commodity hardware. The SDC sharply contrasts to most existing data centers that do not support spatio-temporal sensor data storage, retrieval, and processing. In this paper, we especially focus on the problem of potential load imbalance due to data access skews that adversely affects the timeliness of parallel sensor data processing. Specifically, we present an adaptive data replication method to address access skews in a SDC. In our performance evaluation performed in a preliminary version of a SDC, our adaptive approach substantially outperforms a baseline that does not support adaptive data replication.
The technology of Wireless sensor Networks (WSNs) has been applied to automatic monitoring systems, and used in a wide variety of environments. In this paper, the authors evaluate the performance of a cooperative tech...
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ISBN:
(纸本)9781479946181
The technology of Wireless sensor Networks (WSNs) has been applied to automatic monitoring systems, and used in a wide variety of environments. In this paper, the authors evaluate the performance of a cooperative technique, applied to heterogeneous WSNs. The main contribution is the analysis of the impacts between the energy factor, the channel Signal-to-Noise Ratio (SNR) and the packet loss rate. The analysis also considers the energy consumption aspect. The cooperative modulation diversity performance is evaluated for different propagation scenarios and for two values of interleaving depth (K). A large value for K, leads the network to present lower values of packet lost rate. Some limiting conditions are obtained and the retransmission algorithm is discussed.
The Deterministic and Synchronous Multi-Channel Extension (DSME) protocol is a recent amendment to the ieee 802.15.4 standard. It combines contention-based and time-division medium access, offers channel diversity, an...
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ISBN:
(纸本)9781728105703
The Deterministic and Synchronous Multi-Channel Extension (DSME) protocol is a recent amendment to the ieee 802.15.4 standard. It combines contention-based and time-division medium access, offers channel diversity, and is aimed to support IIoT applications with stringent requirements in terms of timeliness and reliability. In this paper, we show how to configure DSME for a given data collection task. This includes the definition of the slot and frame length and the slot and channel schedule. We formulate different scheduling strategies as linear programs minimizing latency and energy. We verify our results through theoretical analysis and simulations and compare them with state-of-the-art scheduling algorithms. The results indicate a reduced delay of up to 80% for deep networks while also increasing reliability. Additionally, the proposed scheduling strategies significantly reduce the required buffer size.
The complexity of in -vehicle interaction systems is constantly growing. However, thanks to the increased availability of sensing systems in the driving environment and communication infrastructure able to radically c...
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ISBN:
(纸本)9781728105703
The complexity of in -vehicle interaction systems is constantly growing. However, thanks to the increased availability of sensing systems in the driving environment and communication infrastructure able to radically change the interaction modalities at driving, the existing situation is likely to progressively turn into a cooperative scenario, in which the vehicle and the driver share tasks at perceptual, decisional and control level. This paper describes an innovative humanmachine interaction paradigm developed in the SAFE STRIP project to exploit the potential of C -ITS to implement new mobility paradigms, to turn the traditional vehicle perspective into a more efficient traffic perspective. In order to achieve this challenging objective, the overall HMI strategy has been redesigned, to foster the adoption of a new, more active role of the driver and the other road users. The preliminary prototypes developed in the SAFE STRIP project are also described in this paper.
The MAC protocol ieee 802.15.4 DSME has features for WSNs to support exigent requirements such as high reliability and adaptability to dynamic traffic. This work introduces the concept of a virtual sink, which compris...
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ISBN:
(纸本)9781665495127
The MAC protocol ieee 802.15.4 DSME has features for WSNs to support exigent requirements such as high reliability and adaptability to dynamic traffic. This work introduces the concept of a virtual sink, which comprises the sink and its 1-hop neighbors, a.k.a. satellites, as the core of a strategy to alleviate the burden caused by the funneling effect in data collection scenarios. Our strategy enables the coexistence of a centralized scheduling algorithm at the virtual sink and a decentralized scheduling algorithm for the remaining nodes of the network. Through a simulative assessment, we compare the performance of the virtual sink-based strategy with the status quo of DSME via a decentralized slot scheduler TPS. Results show an improvement of the network throughput of up to 38% and a reduction of the energy consumption of about 30% at satellites.
Edge computing established paradigms are prone to implicate solely powerful server-like edge nodes, in static or semistatic topologies, of centrally-controlled edge networks. In this paper, leveraging upon recent tech...
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ISBN:
(纸本)9781728143514
Edge computing established paradigms are prone to implicate solely powerful server-like edge nodes, in static or semistatic topologies, of centrally-controlled edge networks. In this paper, leveraging upon recent technological advancements and trends, we introduce a novel networking paradigm employing resources provided by independent crowd peers, within a zone of local proximity, to establish collaborative networks for edge computing. We call this paradigm the Crowdsourced Edge. We detail the architecture and characteristics of this novel paradigm, highlighting its unique characteristics and specific challenges, while also positioning it vis-a-vis the existing edge computing concretisations. Finally, we demonstrate the Crowdsourced Edge functionality by presenting an ongoing use case regarding a video-enhanced object search.
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