Wireless body area networks （WBANs） can provide low-cost, timely healthcare services and are expected to be widely used for e-healthcare in hospitals. In a hospital, space is often limited and multiple WBANs have to...Wireless body area networks （WBANs） can provide low-cost, timely healthcare services and are expected to be widely used for e-healthcare in hospitals. In a hospital, space is often limited and multiple WBANs have to coexist in an area and share the same channel in order to provide healthcare services to different patients. This causes severe interference between WBANs that could significantly reduce the network throughput and increase the amount of power consumed by sensors placed on the body. There-fore, an efficient channel-resource allocation scheme in the medium access control （MAC） layer is crucial. In this paper, we devel-op a centralized MAC layer resource allocation scheme for a WBAN. We focus on mitigating the interference between WBANs and reducing the power consumed by sensors. Channel and buffer state are reported by smartphones deployed in each WBAN, and channel access allocation is performed by a central controller to maximize network throughput. Sensors have strict limitations in terms of energy consumption and computing capability and cannot provide all the necessary information for channel allocation in a timely manner. This deteriorates network performance. We exploit the temporal correlation of the body area channel in order to minimize the number of channel state reports necessary. We view the network design as a partly observable optimization prob-lem and develop a myopic policy, which we then simulate in Matlab.展开更多
This paper uses the hardware with ZigBee standard and communication protocol, it consists of wireless sensor network in the greenhouse that can timely sample temperature, humidity, collection of environmental paramete...This paper uses the hardware with ZigBee standard and communication protocol, it consists of wireless sensor network in the greenhouse that can timely sample temperature, humidity, collection of environmental parameters. At the same time, this design uses the GPRS module, the data will be collected through the Internet and send to the PC server, and can receive control instructions from the host computer, through the adjustment of agricultural facilities valve to reverse control environment parameters.展开更多
Environmental parameter measurements from various sensors spatially distributed in greenhouse crops can be used to create an accurate and detailed depiction of the climate in different regions of the greenhouse.Microc...Environmental parameter measurements from various sensors spatially distributed in greenhouse crops can be used to create an accurate and detailed depiction of the climate in different regions of the greenhouse.Microclimate environments have an impact on crop yield,productivity,quantitative and qualitative characteristics of plants,and various plant diseases.In this study,an automatic monitoring system based on a wireless sensor network was designed to monitor the survival rate of greenhouse crops.The system design includes a sensor model selection and placement process,host computer monitoring software and communication module design.The Zigbee protocol was used for wireless communication between the nodes.The proposed fuzzy-PID controller was easy to design and highly adaptive to the measurement errors of the sensors.The test results show that the system valuable for monitoring the environment in the greenhouse,where it was successful in controlling and maintaining an optimal microclimate condition.展开更多
针对基于无线传感器网络构建的温室环境控制系统,为了减少无线网络固有的时变传输延时、丢包、网络拥塞等现象对控制性能的影响,该文从提高网络服务质量(quality of service,QoS)的角度出发,提出一种基于Takagi-Sugeno模糊控制器的QoS...针对基于无线传感器网络构建的温室环境控制系统,为了减少无线网络固有的时变传输延时、丢包、网络拥塞等现象对控制性能的影响,该文从提高网络服务质量(quality of service,QoS)的角度出发,提出一种基于Takagi-Sugeno模糊控制器的QoS管理策略。该QoS管理策略以截止期错失率作为QoS性能评价指标,针对传感器节点和执行器节点之间的数据传输,通过动态调整传感器节点的采样周期,使截止期错失率维持在设定水平,从而提高网络QoS。初步试验表明了该QoS管理策略的合理性、有效性和实用性。该QoS管理策略可以广泛应用于温室、农田、苗圃等区域。该研究为提高无线传感器网络在设施农业中的应用水平做出了有益探索。展开更多
基金supported by a research grant from the Natural Science and Engineering Research Council(NSERC)under grant No.CRDPJ 419147-11Care In Motion Inc.,Canada
文摘Wireless body area networks （WBANs） can provide low-cost, timely healthcare services and are expected to be widely used for e-healthcare in hospitals. In a hospital, space is often limited and multiple WBANs have to coexist in an area and share the same channel in order to provide healthcare services to different patients. This causes severe interference between WBANs that could significantly reduce the network throughput and increase the amount of power consumed by sensors placed on the body. There-fore, an efficient channel-resource allocation scheme in the medium access control （MAC） layer is crucial. In this paper, we devel-op a centralized MAC layer resource allocation scheme for a WBAN. We focus on mitigating the interference between WBANs and reducing the power consumed by sensors. Channel and buffer state are reported by smartphones deployed in each WBAN, and channel access allocation is performed by a central controller to maximize network throughput. Sensors have strict limitations in terms of energy consumption and computing capability and cannot provide all the necessary information for channel allocation in a timely manner. This deteriorates network performance. We exploit the temporal correlation of the body area channel in order to minimize the number of channel state reports necessary. We view the network design as a partly observable optimization prob-lem and develop a myopic policy, which we then simulate in Matlab.
文摘This paper uses the hardware with ZigBee standard and communication protocol, it consists of wireless sensor network in the greenhouse that can timely sample temperature, humidity, collection of environmental parameters. At the same time, this design uses the GPRS module, the data will be collected through the Internet and send to the PC server, and can receive control instructions from the host computer, through the adjustment of agricultural facilities valve to reverse control environment parameters.
基金This work is financially supported by the National Natural Science Foundation of China(No.31901400)Zhejiang Province Natural Science Foundation(No.LQ20C130008)the Key Laboratory of Equipment and the Informatization in Environment Controlled Agriculture,Ministry of Agriculture and Rural Affairs(No.2011NYZD1802).
文摘Environmental parameter measurements from various sensors spatially distributed in greenhouse crops can be used to create an accurate and detailed depiction of the climate in different regions of the greenhouse.Microclimate environments have an impact on crop yield,productivity,quantitative and qualitative characteristics of plants,and various plant diseases.In this study,an automatic monitoring system based on a wireless sensor network was designed to monitor the survival rate of greenhouse crops.The system design includes a sensor model selection and placement process,host computer monitoring software and communication module design.The Zigbee protocol was used for wireless communication between the nodes.The proposed fuzzy-PID controller was easy to design and highly adaptive to the measurement errors of the sensors.The test results show that the system valuable for monitoring the environment in the greenhouse,where it was successful in controlling and maintaining an optimal microclimate condition.
文摘针对基于无线传感器网络构建的温室环境控制系统,为了减少无线网络固有的时变传输延时、丢包、网络拥塞等现象对控制性能的影响,该文从提高网络服务质量(quality of service,QoS)的角度出发,提出一种基于Takagi-Sugeno模糊控制器的QoS管理策略。该QoS管理策略以截止期错失率作为QoS性能评价指标,针对传感器节点和执行器节点之间的数据传输,通过动态调整传感器节点的采样周期,使截止期错失率维持在设定水平,从而提高网络QoS。初步试验表明了该QoS管理策略的合理性、有效性和实用性。该QoS管理策略可以广泛应用于温室、农田、苗圃等区域。该研究为提高无线传感器网络在设施农业中的应用水平做出了有益探索。
