Visible Light Communication(VLC)technology is aggressive research for the next generation of communication.Currently,Radio Frequency(RF)communication has crowed spectrum.An Intelligent Transportation System(ITS)has be...Visible Light Communication(VLC)technology is aggressive research for the next generation of communication.Currently,Radio Frequency(RF)communication has crowed spectrum.An Intelligent Transportation System(ITS)has been improved in the communication network for Vehicle-to-Vehicle(V2 V),Vehicle-to-Infrastructure(V2I),and Infrastructure-to-Vehicle(I2V)by using the visible light spectrum instead of the RF spectrum.This article studies the characterization of Line-of-Sight(LOS)optical performance in an Outdoor Wireless Visible Light Communication(OWVLC)system employing a Multiple-Input Multiple-Output(MIMO)technique for I2V communications in ITS regulations.We design the new configuration of the OWVLC-I2V system,which is an alternative approach to communication for I2V system at nighttime.The results show the Channel Impulse Response(CIR)of the LOS links in visible light communication for I2V system in ITS by investigating the receiver on the vehicle moving along the coverage communication area.Furthermore,the OWVLC-I2V system using the MIMO technique depicts the performance of throughput and Bit Error Rate(BER)vs.vehicle speed while the vehicle passes a street light.展开更多
Vehicle to Infrastructure(V2I)communications aim to provide mobile users on the road low-cost Internet and driver safety services.However,to meet Quality of Service(QoS)requirements of various applications and officie...Vehicle to Infrastructure(V2I)communications aim to provide mobile users on the road low-cost Internet and driver safety services.However,to meet Quality of Service(QoS)requirements of various applications and officiently utilize limited wireless channel resourc-es,the transport layer protocol has to perform effective rate control in low channel quality and frequent changing topology communica-tion environment.In this paper,we propose a novel rate-control scheme in infrastructure based vehicular networks that avoids conges-tion and starvation and promotes fairness in end-to-end V2I communications.In vehicular networks,a bottleneck roadside unit(RSU)keeps track of its buffer size,aggregate incoming rate,and link throughput,and appropriately allocates bandwidth to traversing flows.With feedback information from the RSU,source nodes dynamically adjust their sending rates to avoid buffer overflow or starvation at the bottleneck RSU.Simulation results show that the proposed scheme can reduce not only packet losses owing to buffer overflow but also buffer starvation time,which improves the utilization efficiency of wireless channel resource.展开更多
In recent years,Digital Twin(DT)has emerged as a transformative paradigm for enabling the future of the Internet of Things.By mapping the real-time status of physical entities to their digital counterparts,DTs facilit...In recent years,Digital Twin(DT)has emerged as a transformative paradigm for enabling the future of the Internet of Things.By mapping the real-time status of physical entities to their digital counterparts,DTs facilitate the creation of high-fidelity,interactive environments suitable for advanced simulation and deeper insight.One of the key challenges lies in achieving a sufficient level of convergence between Physical Twins(PTs)and their corresponding DTs.To tackle this challenge,we introduce a mobile edge computing environment that enables the coordination between PTs and DTs in Digital Twin Networks(DTNs)by offloading data transmission and processing tasks to the edge.A Hierarchical Deep Reinforcement Learning(HDRL)framework is proposed to improve DT-PT synchronization and enhance coordination effectiveness in optimizing information freshness across multiple action policies within the Digital Twin Communication Infrastructure(DTCI).Our approach is validated through a DTCI simulator,where comprehensive evaluations of age of information performance are conducted.Experimental results show that our HDRL-based solution significantly enhances the information freshness under constrained DTCI resources and across diverse environmental conditions.展开更多
This article examines the architecture of software-defined networks (SDN) and its implications for the modern management of communications infrastructures. By decoupling the control plane from the data plane, SDN offe...This article examines the architecture of software-defined networks (SDN) and its implications for the modern management of communications infrastructures. By decoupling the control plane from the data plane, SDN offers increased flexibility and programmability, enabling rapid adaptation to changing user requirements. However, this new approach poses significant challenges in terms of security, fault tolerance, and interoperability. This paper highlights these challenges and explores current strategies to ensure the resilience and reliability of SDN networks in the face of threats and failures. In addition, we analyze the future outlook for SDN and the importance of integrating robust security solutions into these infrastructures.展开更多
Information and communication technology plays an important role in human life and social production.The existing literature has mainly studied the economic impact of such technology in developed countries;the use of ...Information and communication technology plays an important role in human life and social production.The existing literature has mainly studied the economic impact of such technology in developed countries;the use of broadband in developing countries has been overlooked.This paper fills the gap by examining a broadband development program in China.Difference-in-difference estimates show that the deployment of high-quality broadband promoted regional employment in the skilled service sector.The effect was larger in cities with a greater number of educated residents and cities in the west of China.We also found that broadband development stimulated firm creation and innovation.These findings imply that broadband promotes innovation and provides new impetus to the economic transition of emerging markets.展开更多
基金supported in part by the Ministry of Higher Education,Science and Research Innovation of Thailand.
文摘Visible Light Communication(VLC)technology is aggressive research for the next generation of communication.Currently,Radio Frequency(RF)communication has crowed spectrum.An Intelligent Transportation System(ITS)has been improved in the communication network for Vehicle-to-Vehicle(V2 V),Vehicle-to-Infrastructure(V2I),and Infrastructure-to-Vehicle(I2V)by using the visible light spectrum instead of the RF spectrum.This article studies the characterization of Line-of-Sight(LOS)optical performance in an Outdoor Wireless Visible Light Communication(OWVLC)system employing a Multiple-Input Multiple-Output(MIMO)technique for I2V communications in ITS regulations.We design the new configuration of the OWVLC-I2V system,which is an alternative approach to communication for I2V system at nighttime.The results show the Channel Impulse Response(CIR)of the LOS links in visible light communication for I2V system in ITS by investigating the receiver on the vehicle moving along the coverage communication area.Furthermore,the OWVLC-I2V system using the MIMO technique depicts the performance of throughput and Bit Error Rate(BER)vs.vehicle speed while the vehicle passes a street light.
基金partially supported by the National Natural Science Foundation of China under Grant No.61101121National High Technology Research and Development Programunder Grant No.2013AA102505+2 种基金Key Laboratory Project Funds of Shenyang Ligong University under Grant No.4771004kfs03Zhejiang Provincial Natural Science Foundation of China under Grant No.LY12F01021Educational Committee of Liaoning Province science and technology research projects under Grant No.L2013096
文摘Vehicle to Infrastructure(V2I)communications aim to provide mobile users on the road low-cost Internet and driver safety services.However,to meet Quality of Service(QoS)requirements of various applications and officiently utilize limited wireless channel resourc-es,the transport layer protocol has to perform effective rate control in low channel quality and frequent changing topology communica-tion environment.In this paper,we propose a novel rate-control scheme in infrastructure based vehicular networks that avoids conges-tion and starvation and promotes fairness in end-to-end V2I communications.In vehicular networks,a bottleneck roadside unit(RSU)keeps track of its buffer size,aggregate incoming rate,and link throughput,and appropriately allocates bandwidth to traversing flows.With feedback information from the RSU,source nodes dynamically adjust their sending rates to avoid buffer overflow or starvation at the bottleneck RSU.Simulation results show that the proposed scheme can reduce not only packet losses owing to buffer overflow but also buffer starvation time,which improves the utilization efficiency of wireless channel resource.
基金supported by the U.S.National Science Foundation(Nos.2416872,2244219,2315596,and 2146497).
文摘In recent years,Digital Twin(DT)has emerged as a transformative paradigm for enabling the future of the Internet of Things.By mapping the real-time status of physical entities to their digital counterparts,DTs facilitate the creation of high-fidelity,interactive environments suitable for advanced simulation and deeper insight.One of the key challenges lies in achieving a sufficient level of convergence between Physical Twins(PTs)and their corresponding DTs.To tackle this challenge,we introduce a mobile edge computing environment that enables the coordination between PTs and DTs in Digital Twin Networks(DTNs)by offloading data transmission and processing tasks to the edge.A Hierarchical Deep Reinforcement Learning(HDRL)framework is proposed to improve DT-PT synchronization and enhance coordination effectiveness in optimizing information freshness across multiple action policies within the Digital Twin Communication Infrastructure(DTCI).Our approach is validated through a DTCI simulator,where comprehensive evaluations of age of information performance are conducted.Experimental results show that our HDRL-based solution significantly enhances the information freshness under constrained DTCI resources and across diverse environmental conditions.
文摘This article examines the architecture of software-defined networks (SDN) and its implications for the modern management of communications infrastructures. By decoupling the control plane from the data plane, SDN offers increased flexibility and programmability, enabling rapid adaptation to changing user requirements. However, this new approach poses significant challenges in terms of security, fault tolerance, and interoperability. This paper highlights these challenges and explores current strategies to ensure the resilience and reliability of SDN networks in the face of threats and failures. In addition, we analyze the future outlook for SDN and the importance of integrating robust security solutions into these infrastructures.
基金Qing Wang acknowledges the financial assistance provided by the National Natural Science Foundation of China(No.71903007).
文摘Information and communication technology plays an important role in human life and social production.The existing literature has mainly studied the economic impact of such technology in developed countries;the use of broadband in developing countries has been overlooked.This paper fills the gap by examining a broadband development program in China.Difference-in-difference estimates show that the deployment of high-quality broadband promoted regional employment in the skilled service sector.The effect was larger in cities with a greater number of educated residents and cities in the west of China.We also found that broadband development stimulated firm creation and innovation.These findings imply that broadband promotes innovation and provides new impetus to the economic transition of emerging markets.
