Age Of Information Analysis For UAV-Assisted Internet Of Things Communication Network

The Internet of Things technology connects the information collection and perception devices through the network,which can realize the intelligent perception,identification,control and management of the Internet of Things devices and their information collection process.With the continuous growth of communication businesses facing the demand of Information timeliness,Age of Information(Aol)has been proposed as a new performance indicator different from traditional indicators such as delay to describe the timeliness or freshness of information in the network.As a mobile and flexible new communication platform,UAV can be flexibly deployed according to the requirements of communication tasks.As an aerial aggregation node,UAV can assist Internet of Things devices in data aggregation and transmission,improving the coverage performance of Internet of Things communication network and the timeliness of information collection.This paper takes the UAV-assisted Internet of Things communication network as the research object,analyzes the age of information under different network scenarios,and adopts the power control strategy to further improve the freshness of status updates.The main research contents of this paper are as follows:(1)In a noise-limited network scenario,aiming at the random deployment characteristics of UAV and ground IoT devices,The average age of information in this scenario is deduced and verified by using the stochastic geometry tool to establish the theoretical analysis framework of network related performance indicators.First,a general expression of average Ao I is obtained in a time-slot communication system with a zero cache queue,then,the uplink successful transmission probability of typical IoT devices is derived.Secondly,the theoretical expression of the network average age of information was obtained by deducing the Meta distribution.Finally,the theoretical analysis is verified by simulation experiments and the methods to improve the freshness of information are discussed.(2)In a interference-limited network scenario,the average age of information is analyzed and deduced by considering the same frequency interference of Internet of Things devices and the line-of-sight/non-line-of-sight air-to-ground channel model.Firstly,the link types and link length probability density functions associated with typical IoT devices to their service UAV are derived under the strongest average signal association strategy.Then,the stochastic geometry tool is used to deduce the uplink interference distribution of the network,obtain the uplink successful transmission probability of typical IoT devices.Then,the b-moment of Meta distribution in this network scenario is derived,and theoretical expression of average age of information in network is obtained.Finally,the validity of theoretical analysis is verified by simulation experiments,and the influence of important performance parameters on the age of information and probability of uplink successful transmission is further quantified.(3)On the basis of research content(2),The uplink power control strategy is used to analyze the average age of information of the network and the information freshness is improved by setting corresponding parameters.Considering path dependence of power control strategy,firstly,the correlation between communication link and interference link is analyzed and IoT devices are classified.Then,through the characterization of network interference,the theoretical expression of the probability of successful uplink transmission of typical IoT devices under this power control strategy is obtained.The expression of average age of information was obtained by deducing the Meta distribution of the network.Finally,by analyzing the influence of different power control factors on the network age of information,the power control strategies for reducing the average age of information in different scenarios are proposed.