Simultaneous use of heterogeneous radio access technologies to increase the performance of real-time,reliability and capacity is an inherent feature of satellite-5G integrated network(Sat5G).However,there is still a l...Simultaneous use of heterogeneous radio access technologies to increase the performance of real-time,reliability and capacity is an inherent feature of satellite-5G integrated network(Sat5G).However,there is still a lack of theoretical characterization of whether the network can satisfy the end-to-end transmission performance for latency-sensitive service.To this end,we build a tandem model considering the connection relationship between the various components in Sat5G network architecture,and give an end-to-end latency calculation function based on this model.By introducing stochastic network calculus,we derive the relationship between the end-to-end latency bound and the violation probability considering the traffic characteristics of multimedia.Numerical results demonstrate the impact of different burst states and different service rates on this relationship,which means the higher the burst of arrival traffic and the higher the average rate of arrival traffic,the greater the probability of end-to-end latency violation.The results will provide valuable guidelines for the traffic control and cache management in Sat5G network.展开更多
With the widespread application of wireless communication technology and continuous improvements to Internet of Things(IoT)technology,fog computing architecture composed of edge,fog,and cloud layers have become a rese...With the widespread application of wireless communication technology and continuous improvements to Internet of Things(IoT)technology,fog computing architecture composed of edge,fog,and cloud layers have become a research hotspot.This architecture uses Fog Nodes(FNs)close to users to implement certain cloud functions while compensating for cloud disadvantages.However,because of the limited computing and storage capabilities of a single FN,it is necessary to offload tasks to multiple cooperating FNs for task completion.To effectively and quickly realize task offloading,we use network calculus theory to establish an overall performance model for task offloading in a fog computing environment and propose a Globally Optimal Multi-objective Optimization algorithm for Task Offloading(GOMOTO)based on the performance model.The results show that the proposed model and algorithm can effectively reduce the total delay and total energy consumption of the system and improve the network Quality of Service(QoS).展开更多
Network Calculus is a powerful mathematical theory for the performance evaluation of communication systems;among others it allows to determine worst-case performance measures. This is why it is often used to appoint Q...Network Calculus is a powerful mathematical theory for the performance evaluation of communication systems;among others it allows to determine worst-case performance measures. This is why it is often used to appoint Quality of Service guarantees in packet-switched systems like the internet. The main mathematical operation within this deterministic queuing theory is the min- plus convolution of two functions. For example the convolution of the arrival and service curve of a system which reflects the data’s departure. Considering Quality of Service measures and performance evaluation, the convolution operation plays a considerable important role, similar to classical system theory. Up to the present day, in many cases it is not practical and simple to perform this operation. In this article we describe approaches to simplify the min-plus convolution and, accordingly, facilitate the corresponding calculations.展开更多
Performance evaluation plays a crucial role in the design of network systems. Many theoretical tools, including queueing theory, effective bandwidth and network calculus, have been proposed to provide modeling mechani...Performance evaluation plays a crucial role in the design of network systems. Many theoretical tools, including queueing theory, effective bandwidth and network calculus, have been proposed to provide modeling mechanisms and resuits. While these theories have been widely adopted for performance evaluation, each has its own limitation. With that network systems have become more complex and harder to describe, where a lot of uncertainty and randomness exists, to make performance evaluation of such systems tractable, some compromise is often necessary and helpful. Stochas- tic network calculus （SNC） is such a theoretical tool. While SNC is a relatively new theory, it is gaining increasing interest and popularity. In the current SNC literature, much attention has been paid on the development of the theory itself. In addition, researchers have also started applying SNC to performance analysis of various types of systems in recent years. The aim of this paper is to provide a tutorial on the new theoretical tool. Specifically, various SNC traffic models and SNC server models are reviewed. The focus is on how to apply SNC, for which, four critical steps are formalized and discussed. In addition, a list of SNC application topics/areas, where there may exist huge research potential, is presented.展开更多
This paper focuses on solving the modeling issues of monitoring system service performance based on the network calculus theory.First,we formulate the service model of the smart grid monitoring system.Then,we derive t...This paper focuses on solving the modeling issues of monitoring system service performance based on the network calculus theory.First,we formulate the service model of the smart grid monitoring system.Then,we derive the flow arrival curve based on the incremental process related functions.Next,we develop flow arrival curves for the case of the incremental process being a fractional Gaussian process,and then we obtain the generalized Cauchy process.Three technical theorems related to network calculus are presented as our main results.Mathematically,the variance of arrival flow for the continuous time case is derived.Assuming that the incremental process of network flow is a Gaussian stationary process,and given the auto-correlation function of the incremental process with violation probability,the formula of the arrival curve is derived.In addition,the overall flow variance under the discrete time case is explicitly derived.The theoretical results are evaluated in smart grid applications.Simulations indicate that the generalized Cauchy process outperforms the fractional Gaussian process for our considered problem.展开更多
Mobile edge computing(MEC) networks can provide a variety of services for different applications. End-to-end performance analysis of these services serves as a benchmark for the efficient planning of network resource ...Mobile edge computing(MEC) networks can provide a variety of services for different applications. End-to-end performance analysis of these services serves as a benchmark for the efficient planning of network resource allocation and routing strategies. In this paper, a performance analysis framework is proposed for the end-to-end data-flows in MEC networks based on stochastic network calculus(SNC). Due to the random nature of routing in MEC networks, probability parameters are introduced in the proposed analysis model to characterize this randomness into the derived expressions. Taking actual communication scenarios into consideration, the end-to-end performance of three network data-flows is analyzed, namely, voice over Internet protocol(VoIP), video, and file transfer protocol(FTP). These network data-flows adopt the preemptive priority scheduling scheme. Based on the arrival processes of these three data-flows, the effect of interference on their performances and the service capacity of each node in the MEC networks, closed-form expressions are derived for showing the relationship between delay, backlog upper bounds, and violation probability of the data-flows. Analytical and simulation results show that delay and backlog performances of the data-flows are influenced by the number of hops in the network and the random probability parameters of interference-flow(IF).展开更多
In a cognitive radio network, the secondary users can use the spectrum holes when the primary users do not utilize the spectrum, but they must vacant the spectrum when the primary users need to transmit data on the sp...In a cognitive radio network, the secondary users can use the spectrum holes when the primary users do not utilize the spectrum, but they must vacant the spectrum when the primary users need to transmit data on the spectrum. In other words, the primary users have higher priority over the secondary users. In this paper, backlog and delay distribution bounds for both primary users and secondary users are obtained. The analysis is based on stochastic network calculus, for which, stochastic service curves are t-n-st derived for both primary users and secondary users, and the network calculus independent case analysis approach is used to find the distribution bounds. Numerical results and simulation results are also presented and discussed.展开更多
The aircraft condition monitoring network is responsible for collecting the status of each component in aircraft. The reliability of this network has a significant effect on safety of the aircraft. The aircraft condit...The aircraft condition monitoring network is responsible for collecting the status of each component in aircraft. The reliability of this network has a significant effect on safety of the aircraft. The aircraft condition monitoring network works in a real-time manner that all the data should be transmitted within the deadline to ensure that the control center makes proper decision in time. Only the connectedness between the source node and destination cannot guarantee the data to be transmitted in time. In this paper, we take the time deadline into account and build the task-based reliability model. The binary decision diagram （BDD）, which has the merit of efficiency in computing and storage space, is introduced when calculating the reliability of the network and addressing the essential variable. A case is analyzed using the algorithm proposed in this paper. The experimental results show that our method is efficient and proper for the reliability analysis of the real-time network.展开更多
An Long Term Evolution (LTE) network based mobile Internet of Things (IoT) is modeled and analyzed with the probabilistic delay distribution as the main interest. Stochastic network calculus is relied on to conduct th...An Long Term Evolution (LTE) network based mobile Internet of Things (IoT) is modeled and analyzed with the probabilistic delay distribution as the main interest. Stochastic network calculus is relied on to conduct the analysis. Two typical traffic models, i.e., Compound Poisson and Aggregated ON-OFF Source, are analyzed. The wireless fading channel is modeled as a Gilbert-Elliot channel. Numerical results are presented, where the probabilistic delay distribution and guaranteed capacity under certain delay constraint are shown and discussed.展开更多
Network calculus provides new tools for performance analysis of networks, but analyzing networks with complex topologies is a challenging research issue using statistical network calculus. A service model is proposed ...Network calculus provides new tools for performance analysis of networks, but analyzing networks with complex topologies is a challenging research issue using statistical network calculus. A service model is proposed to characterize a service process of network with complex topologies. To obtain closed-form expression of statistical end-to-end performance bounds for a wide range of traffic source models, the traffic model and service model are expanded according to error function. Based on the proposed models, the explicit end-to-end delay bound of Fractional Brownian Motion（FBM） traffic is derived, the factors that affect the delay bound are analyzed, and a comparison between theoretical and simulation results is performed. The results illustrate that the proposed models not only fit the network behaviors well, but also facilitate the network performance analysis.展开更多
In response to the requirements for large-scale device access and ultra-reliable and low-latency communication in the power internet of things,unmanned aerial vehicle-assisted multi-access edge computing can be used t...In response to the requirements for large-scale device access and ultra-reliable and low-latency communication in the power internet of things,unmanned aerial vehicle-assisted multi-access edge computing can be used to realize flexible access to power services and update large amounts of information in a timely manner.By considering factors such as machine communication traffic,MAC competition access,and information freshness,this paper develops a cross-layer computing framework in which the peak Age of Information(Ao I)provides a statistical delay boundary in the finite blocklength regime.We also propose a deep machine learning-based multi-access edge computing offloading algorithm.First,a traffic arrival model is established in which the time interval follows the Beta distribution,and then a business service model is proposed based on the carrier sense multiple access with collision avoidance algorithm.The peak Ao I boundary performance of multiple access is evaluated according to stochastic network calculus theory.Finally,an unmanned aerial vehicle-assisted multilevel offloading model with cache is designed,in which the peak Ao I violation probability and energy consumption provide the optimization goals.The optimal offloading strategy is obtained using deep reinforcement learning.Compared with baseline schemes based on non-cooperative game theory with stochastic learning automata and random edge unloading,the proposed algorithm improves the overall performance by approximately 3.52%and 20.73%,respectively,and provides superior deterministic offloading performance by using the peak Ao I boundary.展开更多
In recent years,various internet architectures,such as Integrated Services(IntServ),Differentiated Services(DiffServ),Time Sensitive Networking(TSN)and Deterministic Networking(DetNet),have been proposed to meet the q...In recent years,various internet architectures,such as Integrated Services(IntServ),Differentiated Services(DiffServ),Time Sensitive Networking(TSN)and Deterministic Networking(DetNet),have been proposed to meet the quality-of-service(QoS)requirements of different network services.Concurrently,network calculus has found widespread application in network modeling and QoS analysis.Network calculus abstracts the details of how nodes or networks process data packets using the concept of service curves.This paper summarizes the service curves for typical scheduling algorithms,including Strict Priority(SP),Round Robin(RR),Cycling Queuing and Forwarding(CQF),Time Aware Shaper(TAS),Credit Based Shaper(CBS),and Asynchronous Traffic Shaper(ATS).It introduces the theory of network calculus and then provides an overview of various scheduling algorithms and their associated service curves.The delay bound analysis for different scheduling algorithms in specific scenarios is also conducted for more insights.展开更多
Recently,switched Ethernet has become an active area of research because of its wide uses in industry.However,its uses have various real-time constraints on data communications.This paper analyzes the performance of t...Recently,switched Ethernet has become an active area of research because of its wide uses in industry.However,its uses have various real-time constraints on data communications.This paper analyzes the performance of the line topology switched Ethernet as a data acquisition network.Network calculus theory,which has been successfully applied to assess the real-time performance of packet-switched networks,is used to analyze the networks.To properly describe the activity of switches,a novel approach of modeling data flows into or out of switches is addressed.Based on our model,a concisely analytical expression of the maximal end-to-end delay in line topology switched Ethernet is derived.Finally,the relative simulation results are demonstrated.These results agree well with the analytical results,and thus they validate the data flow modeling techniques.展开更多
The fact that outburst traffic in industrial Ethemet was focused on that would bring self-similar phenomenon leading to the delay increase of the cyclical data, and a hybrid priority queue schedule model was proposed ...The fact that outburst traffic in industrial Ethemet was focused on that would bring self-similar phenomenon leading to the delay increase of the cyclical data, and a hybrid priority queue schedule model was proposed in which the outburst data was given the highest priority. Some properties of the self-similar outburst data were proved by network calculus, and its service curve scheduled by the switch was gained. And then the performance of the scheduling algorithm was obtained. The simulation results are close to those calculated by using network calculus model. Some results are of actual significance to the construction of switched industrial Ethernet.展开更多
A key infrastructure component of phasor-based wide-area monitoring and control systems(WAMCS)for multienergy systems is the requirement that the practical network communication should not only be reliable but also su...A key infrastructure component of phasor-based wide-area monitoring and control systems(WAMCS)for multienergy systems is the requirement that the practical network communication should not only be reliable but also sufficiently effective to ensure real time monitoring and fast control.However,the rise in the deployment of phasor measurement units(PMUs)has increased the effective attack surface available to attackers and wide area measurement system(WAMS)applications.Such applications have strict and stringent delay request,e.g.end to end delay as well as delay variation between measurements from different PMUs.In order to solve this problem,this paper proposed that the communication network hierarchy is an effective method for evaluating latency by considering the dynamic characteristics of the PMU data stream in the WAMS.Compared with the existing methods,where the upper bound of delay was given,the proposed method is approximated to the real latency in order to enhance the performance of the controller by considering the delay compensation.In this paper,a three-layer hierarchical distributed topology structure of the WAMS communication network was therefore constructed.Using the dynamic characteristics of time-division grading and sampling intervals with the PMU data stream of the WAMS communication network,the network calculus algorithm was exploited to assess the latency of the dynamic PMU data stream for a 50 Hz power system.Finally,an OPNET-based three-layer communication network simulation model was established.In order to demonstrate the effectiveness of the proposed method,the results from a simulation controller are presented.展开更多
To realize optimal day-ahead operation of battery swapping and charging systems(BSCSs),a closed loop supply chain(CLSC)based management scheme is proposed,where the game theory is adopted for benefits allocation.The C...To realize optimal day-ahead operation of battery swapping and charging systems(BSCSs),a closed loop supply chain(CLSC)based management scheme is proposed,where the game theory is adopted for benefits allocation.The CLSC is used to depict the battery-swapping-charging process between the battery charging stations(BCSs)and battery swapping stations(BSSs).The arrival,departure and swapping service of electric vehicles(EVs)at BSSs is modeled as distinct queues based on the network calculus theory.The depleted batteries(DBs)and well-charging batteries(WBs)based interaction among BCSs and BSSs is formulated as a Stackelberg game.In the game,one BCS acts as the leader and the BSSs act as the followers.The BCS sets optimized prices to maximize its utility and the BSSs optimally demand WBs,supply DBs and provide battery swapping services to maximize their own utilities while guaranteeing the quality of service(QoS)needed for battery swapping.The existence of Stackelberg equilibriums(SEs)of the proposed game is proved.A differential evaluation based hybrid algorithm is proposed to compute an SE.The effectiveness of proposed method has been demonstrated by the simulation results,guaranteeing the QoS and balancing benefits among the BCS and BSSs while maximizing social welfare.展开更多
This paper studies the relationship between two principal tools for the analysis of network traffic, namely, effective bandwidth and network calculus. It is shown that a general formulation of effective bandwidth can ...This paper studies the relationship between two principal tools for the analysis of network traffic, namely, effective bandwidth and network calculus. It is shown that a general formulation of effective bandwidth can be expressed within the framework of a probabilistic version of the network calculus, where both arrivals and service are specified in terms of probabilistic bounds. Aggregate scheduling with statistical service assurances based on statistical network calculus is presented by strong effective envelope function, instead of commonly used effective envelope to obtain bounds on the amount of traffic on a link, the proposed scheme can overcome the overestimation of the number of admitted flows, which makes it superior to the previous scheme especially when implementing call admission control.展开更多
基金This work was supported by the National Natural Science Foundation of China under Grants 61801073,61722105,61931004the Natural Science Foundation of Liaoning Province under Grant 20170540034.
文摘Simultaneous use of heterogeneous radio access technologies to increase the performance of real-time,reliability and capacity is an inherent feature of satellite-5G integrated network(Sat5G).However,there is still a lack of theoretical characterization of whether the network can satisfy the end-to-end transmission performance for latency-sensitive service.To this end,we build a tandem model considering the connection relationship between the various components in Sat5G network architecture,and give an end-to-end latency calculation function based on this model.By introducing stochastic network calculus,we derive the relationship between the end-to-end latency bound and the violation probability considering the traffic characteristics of multimedia.Numerical results demonstrate the impact of different burst states and different service rates on this relationship,which means the higher the burst of arrival traffic and the higher the average rate of arrival traffic,the greater the probability of end-to-end latency violation.The results will provide valuable guidelines for the traffic control and cache management in Sat5G network.
基金This work was supported in part by the Natural Science Foundation of China(Nos.61572191 and 61602171)the Natural Science Foundation of Hunan Province,China(Nos.2022JJ30398 and 2021JJ30455).
文摘With the widespread application of wireless communication technology and continuous improvements to Internet of Things(IoT)technology,fog computing architecture composed of edge,fog,and cloud layers have become a research hotspot.This architecture uses Fog Nodes(FNs)close to users to implement certain cloud functions while compensating for cloud disadvantages.However,because of the limited computing and storage capabilities of a single FN,it is necessary to offload tasks to multiple cooperating FNs for task completion.To effectively and quickly realize task offloading,we use network calculus theory to establish an overall performance model for task offloading in a fog computing environment and propose a Globally Optimal Multi-objective Optimization algorithm for Task Offloading(GOMOTO)based on the performance model.The results show that the proposed model and algorithm can effectively reduce the total delay and total energy consumption of the system and improve the network Quality of Service(QoS).
文摘Network Calculus is a powerful mathematical theory for the performance evaluation of communication systems;among others it allows to determine worst-case performance measures. This is why it is often used to appoint Quality of Service guarantees in packet-switched systems like the internet. The main mathematical operation within this deterministic queuing theory is the min- plus convolution of two functions. For example the convolution of the arrival and service curve of a system which reflects the data’s departure. Considering Quality of Service measures and performance evaluation, the convolution operation plays a considerable important role, similar to classical system theory. Up to the present day, in many cases it is not practical and simple to perform this operation. In this article we describe approaches to simplify the min-plus convolution and, accordingly, facilitate the corresponding calculations.
基金The authors gratefully acknowledge the anonymous reviewers for their constructive comments. This work was supported in part by the National Basic Research Program of China （973） （Grant Nos. 2010CB328105, 2011CB302703）, the National Natural Science Foundation of China （Grant Nos. 60932003, 61071065, 61020106002）.
文摘Performance evaluation plays a crucial role in the design of network systems. Many theoretical tools, including queueing theory, effective bandwidth and network calculus, have been proposed to provide modeling mechanisms and resuits. While these theories have been widely adopted for performance evaluation, each has its own limitation. With that network systems have become more complex and harder to describe, where a lot of uncertainty and randomness exists, to make performance evaluation of such systems tractable, some compromise is often necessary and helpful. Stochas- tic network calculus （SNC） is such a theoretical tool. While SNC is a relatively new theory, it is gaining increasing interest and popularity. In the current SNC literature, much attention has been paid on the development of the theory itself. In addition, researchers have also started applying SNC to performance analysis of various types of systems in recent years. The aim of this paper is to provide a tutorial on the new theoretical tool. Specifically, various SNC traffic models and SNC server models are reviewed. The focus is on how to apply SNC, for which, four critical steps are formalized and discussed. In addition, a list of SNC application topics/areas, where there may exist huge research potential, is presented.
基金This work was funded in part by the National Key Research and Development Program of China(Grant No.2017YFE0132100)Tsinghua-Toyota Joint Research Institute Cross-discipline Program,and the BNRist Program(Grant No.BNR2020TD01009).
文摘This paper focuses on solving the modeling issues of monitoring system service performance based on the network calculus theory.First,we formulate the service model of the smart grid monitoring system.Then,we derive the flow arrival curve based on the incremental process related functions.Next,we develop flow arrival curves for the case of the incremental process being a fractional Gaussian process,and then we obtain the generalized Cauchy process.Three technical theorems related to network calculus are presented as our main results.Mathematically,the variance of arrival flow for the continuous time case is derived.Assuming that the incremental process of network flow is a Gaussian stationary process,and given the auto-correlation function of the incremental process with violation probability,the formula of the arrival curve is derived.In addition,the overall flow variance under the discrete time case is explicitly derived.The theoretical results are evaluated in smart grid applications.Simulations indicate that the generalized Cauchy process outperforms the fractional Gaussian process for our considered problem.
基金supported by Natural Science Foundation of China (61871237, 92067101)Program to Cultivate Middleaged and Young Science Leaders of Universities of Jiangsu Province and Key R&D Plan of Jiangsu Province (BE2021013-3)the Youth Foundation of Nanjing Institute of Industry Technology (YK18 - 02012)。
文摘Mobile edge computing(MEC) networks can provide a variety of services for different applications. End-to-end performance analysis of these services serves as a benchmark for the efficient planning of network resource allocation and routing strategies. In this paper, a performance analysis framework is proposed for the end-to-end data-flows in MEC networks based on stochastic network calculus(SNC). Due to the random nature of routing in MEC networks, probability parameters are introduced in the proposed analysis model to characterize this randomness into the derived expressions. Taking actual communication scenarios into consideration, the end-to-end performance of three network data-flows is analyzed, namely, voice over Internet protocol(VoIP), video, and file transfer protocol(FTP). These network data-flows adopt the preemptive priority scheduling scheme. Based on the arrival processes of these three data-flows, the effect of interference on their performances and the service capacity of each node in the MEC networks, closed-form expressions are derived for showing the relationship between delay, backlog upper bounds, and violation probability of the data-flows. Analytical and simulation results show that delay and backlog performances of the data-flows are influenced by the number of hops in the network and the random probability parameters of interference-flow(IF).
文摘In a cognitive radio network, the secondary users can use the spectrum holes when the primary users do not utilize the spectrum, but they must vacant the spectrum when the primary users need to transmit data on the spectrum. In other words, the primary users have higher priority over the secondary users. In this paper, backlog and delay distribution bounds for both primary users and secondary users are obtained. The analysis is based on stochastic network calculus, for which, stochastic service curves are t-n-st derived for both primary users and secondary users, and the network calculus independent case analysis approach is used to find the distribution bounds. Numerical results and simulation results are also presented and discussed.
基金National Natural Science Foundation of China (60879024)
文摘The aircraft condition monitoring network is responsible for collecting the status of each component in aircraft. The reliability of this network has a significant effect on safety of the aircraft. The aircraft condition monitoring network works in a real-time manner that all the data should be transmitted within the deadline to ensure that the control center makes proper decision in time. Only the connectedness between the source node and destination cannot guarantee the data to be transmitted in time. In this paper, we take the time deadline into account and build the task-based reliability model. The binary decision diagram （BDD）, which has the merit of efficiency in computing and storage space, is introduced when calculating the reliability of the network and addressing the essential variable. A case is analyzed using the algorithm proposed in this paper. The experimental results show that our method is efficient and proper for the reliability analysis of the real-time network.
基金supported by Beijing University of Posts and Telecommunications (BUPT) Fund for Young Scholars under Grant No.2011RC0114
文摘An Long Term Evolution (LTE) network based mobile Internet of Things (IoT) is modeled and analyzed with the probabilistic delay distribution as the main interest. Stochastic network calculus is relied on to conduct the analysis. Two typical traffic models, i.e., Compound Poisson and Aggregated ON-OFF Source, are analyzed. The wireless fading channel is modeled as a Gilbert-Elliot channel. Numerical results are presented, where the probabilistic delay distribution and guaranteed capacity under certain delay constraint are shown and discussed.
基金Supported by the National Natural Science Foundation Major Research Plan of China （No. 90718003）, the National Natural Science Foundation of China （No. 60973027）, and the National High Technology Research and Development Program of China （No. 2007AA01Z401 ）.
文摘Network calculus provides new tools for performance analysis of networks, but analyzing networks with complex topologies is a challenging research issue using statistical network calculus. A service model is proposed to characterize a service process of network with complex topologies. To obtain closed-form expression of statistical end-to-end performance bounds for a wide range of traffic source models, the traffic model and service model are expanded according to error function. Based on the proposed models, the explicit end-to-end delay bound of Fractional Brownian Motion（FBM） traffic is derived, the factors that affect the delay bound are analyzed, and a comparison between theoretical and simulation results is performed. The results illustrate that the proposed models not only fit the network behaviors well, but also facilitate the network performance analysis.
基金supported in part by the National Natural Science Foundation of China(Nos.61601182)in part by the Fundamental Research Funds for the Central Universities under Grant 2023MS113。
文摘In response to the requirements for large-scale device access and ultra-reliable and low-latency communication in the power internet of things,unmanned aerial vehicle-assisted multi-access edge computing can be used to realize flexible access to power services and update large amounts of information in a timely manner.By considering factors such as machine communication traffic,MAC competition access,and information freshness,this paper develops a cross-layer computing framework in which the peak Age of Information(Ao I)provides a statistical delay boundary in the finite blocklength regime.We also propose a deep machine learning-based multi-access edge computing offloading algorithm.First,a traffic arrival model is established in which the time interval follows the Beta distribution,and then a business service model is proposed based on the carrier sense multiple access with collision avoidance algorithm.The peak Ao I boundary performance of multiple access is evaluated according to stochastic network calculus theory.Finally,an unmanned aerial vehicle-assisted multilevel offloading model with cache is designed,in which the peak Ao I violation probability and energy consumption provide the optimization goals.The optimal offloading strategy is obtained using deep reinforcement learning.Compared with baseline schemes based on non-cooperative game theory with stochastic learning automata and random edge unloading,the proposed algorithm improves the overall performance by approximately 3.52%and 20.73%,respectively,and provides superior deterministic offloading performance by using the peak Ao I boundary.
基金supported by ZTE Industry-University-Institute Cooperation Funds。
文摘In recent years,various internet architectures,such as Integrated Services(IntServ),Differentiated Services(DiffServ),Time Sensitive Networking(TSN)and Deterministic Networking(DetNet),have been proposed to meet the quality-of-service(QoS)requirements of different network services.Concurrently,network calculus has found widespread application in network modeling and QoS analysis.Network calculus abstracts the details of how nodes or networks process data packets using the concept of service curves.This paper summarizes the service curves for typical scheduling algorithms,including Strict Priority(SP),Round Robin(RR),Cycling Queuing and Forwarding(CQF),Time Aware Shaper(TAS),Credit Based Shaper(CBS),and Asynchronous Traffic Shaper(ATS).It introduces the theory of network calculus and then provides an overview of various scheduling algorithms and their associated service curves.The delay bound analysis for different scheduling algorithms in specific scenarios is also conducted for more insights.
文摘Recently,switched Ethernet has become an active area of research because of its wide uses in industry.However,its uses have various real-time constraints on data communications.This paper analyzes the performance of the line topology switched Ethernet as a data acquisition network.Network calculus theory,which has been successfully applied to assess the real-time performance of packet-switched networks,is used to analyze the networks.To properly describe the activity of switches,a novel approach of modeling data flows into or out of switches is addressed.Based on our model,a concisely analytical expression of the maximal end-to-end delay in line topology switched Ethernet is derived.Finally,the relative simulation results are demonstrated.These results agree well with the analytical results,and thus they validate the data flow modeling techniques.
基金Project( 60425310) supported by the National Science Fund for Distinguished Young Scholars of ChinaProject(05JJ40118) supported by the Natural Science Foundation of Hunan Province, China
文摘The fact that outburst traffic in industrial Ethemet was focused on that would bring self-similar phenomenon leading to the delay increase of the cyclical data, and a hybrid priority queue schedule model was proposed in which the outburst data was given the highest priority. Some properties of the self-similar outburst data were proved by network calculus, and its service curve scheduled by the switch was gained. And then the performance of the scheduling algorithm was obtained. The simulation results are close to those calculated by using network calculus model. Some results are of actual significance to the construction of switched industrial Ethernet.
基金This work was supported by National Key R&D Program of China(No.2017YFB0902200)Science and Technology Project of State Grid Corporation of China(No.5228001700CW,No.5227221600KW).
文摘A key infrastructure component of phasor-based wide-area monitoring and control systems(WAMCS)for multienergy systems is the requirement that the practical network communication should not only be reliable but also sufficiently effective to ensure real time monitoring and fast control.However,the rise in the deployment of phasor measurement units(PMUs)has increased the effective attack surface available to attackers and wide area measurement system(WAMS)applications.Such applications have strict and stringent delay request,e.g.end to end delay as well as delay variation between measurements from different PMUs.In order to solve this problem,this paper proposed that the communication network hierarchy is an effective method for evaluating latency by considering the dynamic characteristics of the PMU data stream in the WAMS.Compared with the existing methods,where the upper bound of delay was given,the proposed method is approximated to the real latency in order to enhance the performance of the controller by considering the delay compensation.In this paper,a three-layer hierarchical distributed topology structure of the WAMS communication network was therefore constructed.Using the dynamic characteristics of time-division grading and sampling intervals with the PMU data stream of the WAMS communication network,the network calculus algorithm was exploited to assess the latency of the dynamic PMU data stream for a 50 Hz power system.Finally,an OPNET-based three-layer communication network simulation model was established.In order to demonstrate the effectiveness of the proposed method,the results from a simulation controller are presented.
基金This work was supported by the Fundamental Research Funds for the Central Universities(No.2014XS09)the China Scholarship Council of the Ministry of Education.
文摘To realize optimal day-ahead operation of battery swapping and charging systems(BSCSs),a closed loop supply chain(CLSC)based management scheme is proposed,where the game theory is adopted for benefits allocation.The CLSC is used to depict the battery-swapping-charging process between the battery charging stations(BCSs)and battery swapping stations(BSSs).The arrival,departure and swapping service of electric vehicles(EVs)at BSSs is modeled as distinct queues based on the network calculus theory.The depleted batteries(DBs)and well-charging batteries(WBs)based interaction among BCSs and BSSs is formulated as a Stackelberg game.In the game,one BCS acts as the leader and the BSSs act as the followers.The BCS sets optimized prices to maximize its utility and the BSSs optimally demand WBs,supply DBs and provide battery swapping services to maximize their own utilities while guaranteeing the quality of service(QoS)needed for battery swapping.The existence of Stackelberg equilibriums(SEs)of the proposed game is proved.A differential evaluation based hybrid algorithm is proposed to compute an SE.The effectiveness of proposed method has been demonstrated by the simulation results,guaranteeing the QoS and balancing benefits among the BCS and BSSs while maximizing social welfare.
文摘This paper studies the relationship between two principal tools for the analysis of network traffic, namely, effective bandwidth and network calculus. It is shown that a general formulation of effective bandwidth can be expressed within the framework of a probabilistic version of the network calculus, where both arrivals and service are specified in terms of probabilistic bounds. Aggregate scheduling with statistical service assurances based on statistical network calculus is presented by strong effective envelope function, instead of commonly used effective envelope to obtain bounds on the amount of traffic on a link, the proposed scheme can overcome the overestimation of the number of admitted flows, which makes it superior to the previous scheme especially when implementing call admission control.
