sensor and Actuator Networks (SAN) are distributed systems deployed to sense, monitor and act on the environment. they may include any of the following: sensors, wiring, embedded system components, wireless communicat...
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We present a sensor network that monitors a hallway. It consists of 180 load sensors connected to 30 wireless sensor nodes, where the setup is of extremely low cost and easily transferred to other settings. Our networ...
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ISBN:
(纸本)9781605587486
We present a sensor network that monitors a hallway. It consists of 180 load sensors connected to 30 wireless sensor nodes, where the setup is of extremely low cost and easily transferred to other settings. Our network serves as a testbed for in-network data processing algorithms, for which it is highly suitable due to the many correlated sensors.
the problem of idle listening is one of the most significant sources of energy consumption in wireless sensor nodes, and many techniques have been proposed based on ditty cycling to reduce this cost. In this paper, we...
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ISBN:
(纸本)9781595939906
the problem of idle listening is one of the most significant sources of energy consumption in wireless sensor nodes, and many techniques have been proposed based on ditty cycling to reduce this cost. In this paper, we present a new asynchronous duty cycle MAC protocol, called Receiver-Initiated MAC (RI-MAC), that uses receiver-initiated data transmission in order to efficiently and effectively operate over a wide range of traffic loads. RI-MAC attempts to minimize the time a sender and its intended receiver occupy the wireless medium to find a rendezvous time for exchanging data, while still decoupling the sender and receiver's duty cycle schedules. We show the performance of RI-MAC through detailed ns-2 simulation and through measurements of an implementation in TinyOS in a testbed of MICAz motes. Compared to the prior asynchronous duty cycling approach of X-MAC, RI-MAC achieves higher throughput, packet delivery ratio, and power efficiency under a wide range of traffic loads. Especially when there are contending flows, such as bursty traffic or transmissions from hidden nodes, RI-MAC significantly improves throughput and packet delivery ratio. Even under light traffic load for which X-MAC is optimized, RI-MAC achieves the same high performance in terms of packet delivery ratio and latency while maintaining comparable power efficiency.
this paper present a wake-on sensor network formed withthe wake-on motes, TelosW. Our wake-on hardware and software design enable lower power operations and longer network lifetime.
ISBN:
(纸本)9781605587486
this paper present a wake-on sensor network formed withthe wake-on motes, TelosW. Our wake-on hardware and software design enable lower power operations and longer network lifetime.
At present, the sensor node platforms from different vendors cannot easily interoperate with each other due to their heterogeneous programming environments, communication stacks and data management protocols. In this ...
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ISBN:
(纸本)9781605587486
At present, the sensor node platforms from different vendors cannot easily interoperate with each other due to their heterogeneous programming environments, communication stacks and data management protocols. In this work, we develop a sensor network virtualization framework that will enable the seamless interoperability and scalability of heterogeneous sensor node platforms.
We present ongoing work to develop a power transformer condition monitoring system. Energy harvesting will be used to power the sensor nodes measuring the vibration of the transformer. A subset of this work will be de...
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ISBN:
(纸本)9781605587486
We present ongoing work to develop a power transformer condition monitoring system. Energy harvesting will be used to power the sensor nodes measuring the vibration of the transformer. A subset of this work will be demonstrated.
Water is nature's most precious resource and growing demand is pushing fresh water supplies to the brink of non-renewability. New technological and social initiatives that enhance conservation and reduce waste are...
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ISBN:
(纸本)9781595939906
Water is nature's most precious resource and growing demand is pushing fresh water supplies to the brink of non-renewability. New technological and social initiatives that enhance conservation and reduce waste are needed. Providing consumers with fine-grained real-time information has yielded benefits in conservation of power and gasoline. Extending this philosophy to water conservation, we introduce a novel water monitoring system, NAWMS, that similarly empowers users. the goal of our work is to furnish users with an easy-to-install self-calibrating system that provides information on when, where, and how much water they are using. the system uses wireless vibration sensors attached to pipes and, thus, neither plumbing nor special expertise is necessary for its installation. By implementing a non-intrusive, autonomous, and adaptive system using commodity hardware, we believe it is cost-effective and widely deployable. NAWMS makes use of the existing household water flow meter, which is considered accurate, but lacks spatial granularity, and adds vibration sensors on individual water pipes to estimate the water flow to each individual outlet. Compensating for manufacturing, installation, and material variabilities requires calibration of these low cost sensors to achieve a reasonable level of accuracy. We have devised an adaptive auto-calibration procedure, which attempts to solve a two phase linear programming and mixed linear geometric programming problem. We show through experiments on a three pipe testbed that such a system is indeed feasible and adapts well to minimize error in the water usage estimate. We report an accuracy, over likely domestic flow-rate scenarios, with long-term stability and a mean absolute error of 7%.
this paper reflects on experiences in deploying middleware for a body sensor network, using commercial biosensors. three types of issues are highlighted that arose during the deployment, which impact middleware design...
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Extensive empirical results reveal that interference can cause link qualities to change quickly and dramatically. For such highly dynamic links, the short term link quality estimations widely used in existing protocol...
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ISBN:
(纸本)9781595939906
Extensive empirical results reveal that interference can cause link qualities to change quickly and dramatically. For such highly dynamic links, the short term link quality estimations widely used in existing protocols require frequent measurements and may riot be accurate. As a, result, when these links are selected, end-to-end communication quality varies significantly. Also, route changes occur frequently, introducing traffic oscillation and excessive overhead in network protocols. To achieve good and stable network performance, it is not enough to rise short term link estimation. It is essential to characterize a link's capacity to perform well at a desired level in the presence of interference and environmental changes. therefore, we propose a performance metric called competence. We have incorporated the competence metric into routing algorithm designs. We have also designed and implemented a maintenance framework that stabilizes performance at both link and network layers. this framework allocates the desired performance level among multiple links along an active route by using an end-to-end feedback loop, and enforces the performance level of each link through adaptive transmission power control and retransmission control. In real system evaluations with 48 T-Motes, our solution Outperforms previous protocols significantly and achieves end-to-end stable performance for more than 99% of the time over 24 hours.
In this demonstration, we will present three key technologies we recently developed to improve time synchronization accuracy in sensor networks: (1) Temperature Driven Time Synchronization, (2) Low-Power Sub-mu Second...
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ISBN:
(纸本)9781605587486
In this demonstration, we will present three key technologies we recently developed to improve time synchronization accuracy in sensor networks: (1) Temperature Driven Time Synchronization, (2) Low-Power Sub-mu Second Time Synchronization, and (3) Low-Power FPGA implementation of a High-Low Timer.
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