In the current protocol stack for Internet of Things in general and wireless sensor network in particular, many devices rely on the ContikiMAC protocol at their MAC layer. This protocol is widely used and enabled by d...
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ISBN:
(纸本)9781479946181
In the current protocol stack for Internet of Things in general and wireless sensor network in particular, many devices rely on the ContikiMAC protocol at their MAC layer. This protocol is widely used and enabled by default for several industrial environments and time sensitive monitoring and control applications. However, few work exists regarding the performance of this protocol because it lacks of an underlying theoretical model for analysing its performance. In this paper, we propose a novel approach relying on process mining technique that aims to obtain a Markov chain model for networks running the ContikiMAC protocol. In particular, we present a comprehensive specification of the protocol and a Markov chain model obtained through the analysis and instrumentation of its reference implementation. We used the obtained Markov chain to analyze and estimate the end to end delay distribution for a multi-hops transmission with static routing. The approach can also be extended to a wide range of protocols.
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.
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 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.
Code dissemination in wireless sensor networks refers to the process of disseminating a new code image via wireless links to all sensor nodes after they are deployed. It is desirable and often necessary due to the nee...
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ISBN:
(纸本)9780769543642
Code dissemination in wireless sensor networks refers to the process of disseminating a new code image via wireless links to all sensor nodes after they are deployed. It is desirable and often necessary due to the need for, e. g., removing program bugs and adding new functionalities in a multi-task sensor network. A sound code dissemination scheme need be both loss-resilient and attack-resilient, which are crucial for sensor networks deployed in lossy and hostile environments. To the best of our knowledge, no existing scheme simultaneously satisfies both requirements. This paper fills this gap with the design and evaluation of LR-Seluge, a novel loss-resilient and secure code dissemination scheme. The efficacy and efficiency of LR-Seluge are confirmed by both theoretical analysis and extensive simulation results. In particular, LR-Seluge can reduce up to 40% communication overhead in lossy environments with the same level of attack resilience in contrast to existing schemes.
Although wireless sensor networks (WSNs) are becoming ubiquitous, the large amount of power consumed by wireless communications in transmitting sensing data from sensors to base stations or between sensor nodes themse...
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ISBN:
(纸本)9781479932474;9780769550237
Although wireless sensor networks (WSNs) are becoming ubiquitous, the large amount of power consumed by wireless communications in transmitting sensing data from sensors to base stations or between sensor nodes themselves has become a critical problem. Since most sensor nodes are powered by batteries, we need to be more energy efficient to improve our ability to maintain them. As it is well-known that long communication distances between sensor nodes and base stations make WSNs consume more power as well as large amounts of sensing data, we propose a new energy-efficient wireless communication protocol called threshold controlled hierarchical routing (TCHR) to reduce the cost of wireless communication by reducing the communication distance in WSNs which the topology is considered closer to reality. We simulated our proposed protocol, and the simulation results demonstrated that the life of a WSN could be extended approximately 6 times longer than that with the direct data transmission protocol.
This paper proposes a MAC protocol for enhancing the throughput in underwater acoustic sensor networks. Since the transmission speed of acoustic wave is much slower than that of radio, the propagation delay in the wat...
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ISBN:
(纸本)9781479932474;9780769550237
This paper proposes a MAC protocol for enhancing the throughput in underwater acoustic sensor networks. Since the transmission speed of acoustic wave is much slower than that of radio, the propagation delay in the water is much longer. For solving the long propagation delay and hidden terminal problems, the throughput may become very low. To improve the throughput, this paper proposes an algorithm to increase the communications by using some resources which are originally idle for protecting communication from interference. The proposed protocol is based on synchronized technologies. Performance study reveals that the proposed protocol outperforms existing work in terms of network throughput and waiting time of nodes.
In this paper we study the problem of minimum connected dominating set in geometric k-disk graphs. This research is motivated by the problem of virtual backbone construction in wireless ad hoc and sensor networks, whe...
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ISBN:
(纸本)9781424431748
In this paper we study the problem of minimum connected dominating set in geometric k-disk graphs. This research is motivated by the problem of virtual backbone construction in wireless ad hoc and sensor networks, where the coverage area of nodes are disks with different radii. We derive the size relationship of any maximal independent set and the minimum connected dominating set in geometric k-disk graphs, and apply it to analyze the performances of two distributed connected dominating set algorithms we propose in this paper These algorithms have a bounded performance ratio and low communication overhead, and therefore have the potential to be applied in real ad hoc and sensor networks.
A common method of prolonging the lifetime of wireless sensor networks is to use low power duty cycling protocol. Existing protocols consist of two categories: sender-initiated, and receiver-initiated. In this paper, ...
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ISBN:
(纸本)9781479932474;9780769550237
A common method of prolonging the lifetime of wireless sensor networks is to use low power duty cycling protocol. Existing protocols consist of two categories: sender-initiated, and receiver-initiated. In this paper, we present SA-MAC, a Self-stabilizing Adaptive MAC protocol for wireless sensor networks. SA-MAC dynamically adjusts the transmission time-slot, waking up time-slot, and packet detection patten according to current network working condition, such as packet length and wake-up patterns of neighboring nodes. In the long run, every sensor node will find its own transmission phase so that the network will enter a stable stage when the network load and qualities are static. We conduct extensive experiments to evaluate the energy consumption, packet reception rate of SA-MAC in real sensor networking systems. Our results indicate that SA-MAC outperforms other existing protocols.
The data association problem appears in many applications and is considered as the most challenging problem in intelligent systems. In this paper, we consider the Bayesian formulation of data association problems and ...
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ISBN:
(纸本)9781457705137
The data association problem appears in many applications and is considered as the most challenging problem in intelligent systems. In this paper, we consider the Bayesian formulation of data association problems and present a deterministic polynomial-time approximation algorithm with guaranteed error bounds using correlation decay from statistical physics. We then show that the proposed algorithm naturally partitions a complex problem into a set of local problems and develop a distributed version of the algorithm. The performance of the proposed algorithm is evaluated in simulation.
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