Lo Ra无线网络技术是一项广泛应用物联网平台的网络通信技术,能够以超低功耗提供长距离连接设施。由于AES-128加密技术用于从终端设备到应用服务器的有效负载传输,因此它提供了强大的安全功能。由于其自身网络体系架构的设计,网关是网...Lo Ra无线网络技术是一项广泛应用物联网平台的网络通信技术,能够以超低功耗提供长距离连接设施。由于AES-128加密技术用于从终端设备到应用服务器的有效负载传输,因此它提供了强大的安全功能。由于其自身网络体系架构的设计,网关是网络中的弱点,这给攻击者提供了可乘之机。提出了一种新的证书认证技术来保护网络中的网关。构建Lo Ra无线网络技术的实验仿真环境进行有效验证,大大提升了Lo Ra无线网络技术的安全性。展开更多
The environmental quality of livestock houses is key to livestock breeding and directly affects the growth and health of animals.To target the characteristics of long application cycles and large coverage areas for en...The environmental quality of livestock houses is key to livestock breeding and directly affects the growth and health of animals.To target the characteristics of long application cycles and large coverage areas for environmental monitoring in large-scale livestock breeding,the current study designed a remote monitoring system to provide livestock environmental information based on LoRa wireless ad hoc network technology.The system consisted of collection terminals,control terminals,LoRa gateways,and Alibaba Elastic Compute Service.It realized real-time collection,wireless transmission,storage of multi-sensor node data,and remote control.The system was not limited by the selected time or region,because data interaction was achieved by accessing cloud servers using GPRS technology.Users could browse and obtain data from computers and a WeChat mini program from any location with network coverage.Additionally,the system used the improved receiver-based auto rate(RBAR)rate-adaptive algorithm in the LoRa wireless communication component.After application on a dairy farm,the results showed that the whole system collected 6140 sets of environmental data from four dairy houses.The packet loss rate was less than 1%within a communication distance of 604 m,and the communication success rate was greater than 99%.The control instructions were real-time and accurate,and the response time was less than 10 s,which met the remote control needs of large farms.The system provided powerful data and technical support for precision animal production.展开更多
在变电站内安装无线传感器网络已经成为发展智能电网的必然趋势。针对变电站中局部放电脉冲噪声对LoRa无线通信产生的干扰问题,首先分析了LoRa调制与解调原理,在该基础上建立了LoRa仿真模型,并根据在高斯白噪声下的解调信噪比验证了模...在变电站内安装无线传感器网络已经成为发展智能电网的必然趋势。针对变电站中局部放电脉冲噪声对LoRa无线通信产生的干扰问题,首先分析了LoRa调制与解调原理,在该基础上建立了LoRa仿真模型,并根据在高斯白噪声下的解调信噪比验证了模型的准确性;然后建立了Middleton Class A脉冲噪声模型,通过数学统计方法检验了特定参数的Middleton Class A脉冲噪声表示实测局部放电信号的准确性;最后通过误码率曲线,分析了在高斯噪声环境和特定参数的Middleton Class A脉冲噪声环境下的LoRa通信性能差异。研究结果表明,LoRa具有优秀的抗噪声能力,即使是在信噪比为负值时仍然允许数据接收;某500 kV变电站实测局部放电信号可以表示为特定参数的Middleton Class A脉冲噪声;与高斯噪声相比,该脉冲噪声会对LoRa系统造成信噪比损失,导致系统通信性能下降。研究结果可为在变电站内部署LoRa无线通信网络提供理论参考。展开更多
基金This work is financially supported by the National Key Research and Development Program of China(Grant No.2019YFE0125600)the National Natural Science Foundation of China(Grant No.32172784)+2 种基金the China Agricultural Research System(CARS-36)the Northeast Agricultural University“East Agricultural Scholar Program(Academic Backbone)”Project(Grant No.20XG37)the University Nursing Program for Young Scholars with Creative Talents in Heilongjiang Province,China(Grant No.UNPYSCT-2020092).
文摘The environmental quality of livestock houses is key to livestock breeding and directly affects the growth and health of animals.To target the characteristics of long application cycles and large coverage areas for environmental monitoring in large-scale livestock breeding,the current study designed a remote monitoring system to provide livestock environmental information based on LoRa wireless ad hoc network technology.The system consisted of collection terminals,control terminals,LoRa gateways,and Alibaba Elastic Compute Service.It realized real-time collection,wireless transmission,storage of multi-sensor node data,and remote control.The system was not limited by the selected time or region,because data interaction was achieved by accessing cloud servers using GPRS technology.Users could browse and obtain data from computers and a WeChat mini program from any location with network coverage.Additionally,the system used the improved receiver-based auto rate(RBAR)rate-adaptive algorithm in the LoRa wireless communication component.After application on a dairy farm,the results showed that the whole system collected 6140 sets of environmental data from four dairy houses.The packet loss rate was less than 1%within a communication distance of 604 m,and the communication success rate was greater than 99%.The control instructions were real-time and accurate,and the response time was less than 10 s,which met the remote control needs of large farms.The system provided powerful data and technical support for precision animal production.
文摘在变电站内安装无线传感器网络已经成为发展智能电网的必然趋势。针对变电站中局部放电脉冲噪声对LoRa无线通信产生的干扰问题,首先分析了LoRa调制与解调原理,在该基础上建立了LoRa仿真模型,并根据在高斯白噪声下的解调信噪比验证了模型的准确性;然后建立了Middleton Class A脉冲噪声模型,通过数学统计方法检验了特定参数的Middleton Class A脉冲噪声表示实测局部放电信号的准确性;最后通过误码率曲线,分析了在高斯噪声环境和特定参数的Middleton Class A脉冲噪声环境下的LoRa通信性能差异。研究结果表明,LoRa具有优秀的抗噪声能力,即使是在信噪比为负值时仍然允许数据接收;某500 kV变电站实测局部放电信号可以表示为特定参数的Middleton Class A脉冲噪声;与高斯噪声相比,该脉冲噪声会对LoRa系统造成信噪比损失,导致系统通信性能下降。研究结果可为在变电站内部署LoRa无线通信网络提供理论参考。