| Wireless sensor networks are gradually used in the management of modern industry and cities due to their low cost and easy deployment.They are used to complete data collection and control,and they have become more productized in recent years.At the same time,due to the trends of integrating Internet of Things and the global Internet,6LoWPAN and other personal area network standards were born to implement IP protocols on embedded devices with severely limited resources.This article focuses on the field of wireless meter reading working on the 6LoWPAN protocol stack.During the actual product experimentation and on-site pilots,it was found that many defects in the existing protocol stack will cause hidden troubles for the reliable working of the meter reading system.Therefore,after detailed analysis of the requirements and limitations of the meter reading system,this paper conducts a detailed verifica t io n analysis of the problems found,and combines the characteristics of the field of meter reading,proposes plans to improve the reliability of the existing protocol stack.In the 6LoWPAN protocol stack,the influence of the channel clear detection threshold on the network performance is not emphasized,and a configuration method of manually configuring a fixed value is adopted.In an actual situation,an inappropriate channel clear detection threshold may seriously affect network reliability and power consumption levels.This paper designs an adaptive channel clear detection threshold algorithm to help different nodes in different network environment to configure more reasonable parameter values,which is verified to help the node resist some of the environmental interference in the network and improves the reliability of the network.However,the adaptive channel clear detection threshold algorithm is not suitable for the situation that the noise influence on a single channel is too strong.Therefore,in this paper,a frequency hopping algorithm is designed on the narrow band which is usual y used in meter reading applications.This algorithm takes full account of the impact of adjacent-channel energy leakage on the frequency hopping performance of the node,and is finally verified to be able to improve the reliability of the network under strong ambient noise interference conditions.In addition,for the problem of poor reliability of unicast downlink in the 6LoWPAN protocol stack,the related research is summarized and analyzed in this paper.However,the reasons found in this paper are different from those in existing work.Therefore,the load-balancing downlink unicast is specifically designed.The routing is verified to be able to improve the reliability of the downlink unicast routing of the network.At the same time,it is also found that the adaptive channel detection threshold algorithm can greatly improves the downlink reliability.Finally,a distributed coarse-grained time synchronization algorithm was designed for the existing time-synchronized clock source single-point faults found during the piloting process,which compensates for the defects and also ensures that the introduced energy consumption costs are low.The paper's conclusion summarizes its improvement of the reliability of the wireless reading system which is based on 6LoWPAN stack,and analyzes the shortcomings of the existing design and other reliability problems needed to be solved in the meter reading system,and proposes future research directions. |
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