Using solar power in wireless sensor networks (WSNs) requires adaptation to a highly varying energy supply. From an application's perspective, however, it is often preferred to operate at a constant quality level ...
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ISBN:
(纸本)9783642020841
Using solar power in wireless sensor networks (WSNs) requires adaptation to a highly varying energy supply. From an application's perspective, however, it is often preferred to operate at a constant quality level as opposed to changing application behavior frequently. Reconciling the varying supply with the fixed demand requires good tools for predicting supply such that its average is computed and demand is fixed accordingly. In this paper, we describe a probabilistic observation-based model for harvested solar energy, which accounts for both long-term tendencies and temporary environmental conditions. Based on this model, we develop a time-slot-based energy allocation scheme to use the periodically harvested solar energy optimally, while minimizing the variance in energy allocation. Our algorithm is tested on both outdoor and indoor testbeds, demonstrating the efficacy of the approach.
This paper addressed the issue of fusing decisions transmitted via Rice fading channels, with censoring transmission strategies. We derived an optimal likelihood ratio rule based on the channel state information. Howe...
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Time Synchronization is the most important component in wireless sensor network (WSN). Since, it improves energy efficiency, lifetime, robustness, precision and so on. The final goal of WSN is Smart Dust. So, WSN devi...
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In recent years, many routing protocols for wireless sensor networks (WSNs) have been designed to achieve high energy-efficiency, high reliability, low overhead, etc. However, few routing protocols for WSNs were desig...
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ISBN:
(纸本)9780769536422
In recent years, many routing protocols for wireless sensor networks (WSNs) have been designed to achieve high energy-efficiency, high reliability, low overhead, etc. However, few routing protocols for WSNs were designed to minimize the communication delay, which is one of the most important requirements for applications of WSNs, such as real-time surveillance systems. In this paper, a novel real-time routing protocol for WSNs is proposed for guaranteeing real-time communication. Additionally, energy-efficiency that prolongs the network lifetime is fully considered. Performance analyses and simulation results show that our protocol has much better performance than Directed Diffusion [2] and Rumor Routing [5] in terms of both communication delay and network lifetime.
Wireless sensor networks (WSNs) play an increasingly important role in civilian and military settings. With the limited energy supply, sensor nodes do neither large calculations nor further transmissions. Data aggrega...
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In wireless sensor network applications, sensor measurements are corrupted by noises resulting from harsh environmental conditions, hardware and transmission errors. Minimising the impact of noise in an energy constra...
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ISBN:
(纸本)9783642020841
In wireless sensor network applications, sensor measurements are corrupted by noises resulting from harsh environmental conditions, hardware and transmission errors. Minimising the impact of noise in an energy constrained sensor network is a challenging task. We study the problem of estimating environmental phenomena (e.g., temperature, humidity, pressure) based on noisy sensor measurements to minimise the estimation error. An environmental phenomenon is modeled using linear Gaussian dynamics and the Kalman filtering technique is used for the estimation. At each time step, a group of sensors is scheduled to transmit data to the base station to minimise the total estimated error for a given energy budget. The sensor scheduling problem is solved by dynamic programming and one-step-look-ahead methods. Simulation results are presented to evaluate the performance of both methods. The dynamic programming method produced better results with higher computational cost than the one-step-look-ahead method.
In this paper we present local distributed algorithms for constructing spanners in wireless sensor networks modeled as unit ball graphs (shortly UBGs) and quasi-unit ball graphs (shortly quasi-UBGs), in the 3-dimensio...
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ISBN:
(纸本)9783642020841
In this paper we present local distributed algorithms for constructing spanners in wireless sensor networks modeled as unit ball graphs (shortly UBGs) and quasi-unit ball graphs (shortly quasi-UBGs), in the 3-dimensional Euclidean space. Our first contribution is a local distributed algorithm that, given a UBG U and a parameter alpha < pi/3, constructs a sparse spanner of U with stretch factor 1/(1 - 2 sin (alpha/2)), improving the previous upper bound of 1/(1 - alpha) by Althofer et al. which is applicable only when alpha < 1/(1 + 2 root-2) < pi/3. The second contribution of this paper is in presenting the first local distributed algorithm for the construction of bounded-degree lightweight spanners of UBGs and quasi-UBGs. The simulation results we obtained show that, empirically, the weight of the spanners, the stretch factor and locality of the algorithms, are much better than the theoretical upper bounds proved in this paper.
Wireless sensor Networks have been widely developed in modern surveillance systems since its complementary and overlapping coverage on targets. In order to track and estimate the path of target, the sensor data should...
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ISBN:
(纸本)9780769535012
Wireless sensor Networks have been widely developed in modern surveillance systems since its complementary and overlapping coverage on targets. In order to track and estimate the path of target, the sensor data should to be fused. However, the information fusion performance is influenced largely due to the presence of disruptions and delays in communication channels between sensor nodes which are not sufficiently solved until now. A stochastic estimation function is proposed in this paper to predict the fusion performance by adopting the effects of network connectivity and message delay into the fusion equations. Compared with the traditional deterministic estimation function, the final equations produced by the method consist of some prior parameters which can be determined according to the specific communication environment where the sensor networks are deployed The simulation results have shown that the stochastic method can reduce the fusion time markedly in addition to provide good estimation capabilities.
The proceedings contain 136 papers. The topics discussed include: a dynamic platform for runtime adaptation;programmable presence virtualization for next-generation context-based applications;distributed policy resolu...
ISBN:
(纸本)9781424433049
The proceedings contain 136 papers. The topics discussed include: a dynamic platform for runtime adaptation;programmable presence virtualization for next-generation context-based applications;distributed policy resolution through negotiation in ubiquitous computing environments;noshake: content stabilization for shaking screens of mobile devices;a mobile product recommendation system interacting with tagged products;DTT: a distributed trust toolkit for pervasive systems;rationalexposure: a game theoretic approach to optimize identity exposure in pervasive computing environments;securing body sensor networks: sensor association and key management;persistent content-based information dissemination in hybrid vehicular networks;a classification and modeling of the quality of contextual information in smart spaces;and design and optimization of spatial organizations for context exchange and surveillance.
Wireless sensor networks (WSNs) have been proposed for a large variety of applications. As the number of applications of sensor networks continue to grow, the number of users in sensor networks increases as well. Cons...
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ISBN:
(纸本)9783642020841
Wireless sensor networks (WSNs) have been proposed for a large variety of applications. As the number of applications of sensor networks continue to grow, the number of users in sensor networks increases as well. Consequently, it is not uncommon that base station often needs to process multiple queries simultaneously. Furthermore, these queries often need to collect data from some particular sets of sensors such as the sensors in a hot spot. To reduce the communication cost of multiple query processing in WSNs, this paper proposes a new optimization technique based on similarities among multiple queries. Given a set of queries, Q, the proposed scheme constructs a set of shared intermediate views (SIVs) from Q. Each SIV identifies a set of shared data among queries in Q. The SIVs, are processed only once, but reused by at least two queries in Q. The queries in Q, are rewritten into a different set of queries, Q' The collected sensor data from Q' and SIVs, are aggregated and returned as the processing results for the original set of queries in Q. The simulation results show that the proposed technique can effectively reduce the communication cost of multiple query processing in WSNs.
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