This work aims to examine the vulnerabilities and threats in the applications of intelligent transport systems,especially collision avoidance protocols.It focuses on achieving the availability of network communication...This work aims to examine the vulnerabilities and threats in the applications of intelligent transport systems,especially collision avoidance protocols.It focuses on achieving the availability of network communication among traveling vehicles.Finally,it aims to find a secure solution to prevent blackhole attacks on vehicular network communications.The proposed solution relies on authenticating vehicles by joining a blockchain network.This technology provides identification information and receives cryptography keys.Moreover,the ad hoc on-demand distance vector(AODV)protocol is used for route discovery and ensuring reliable node communication.The system activates an adaptive mode for monitoring communications and continually adjusts trust scores based on packet delivery performance.From the experimental study,we can infer that the proposed protocol has successfully detected and prevented blackhole attacks for different numbers of simulated vehicles and at different traveling speeds.This reduces accident rates by 60%and increases the packet delivery ratio and the throughput of the connecting network by 40%and 20%,respectively.However,extra overheads in delay and memory are required to create and initialize the blockchain network.展开更多
The goal of an UHDTV is to broadcast digital video contents which is 16 times the pixel resolution of HDTV. As the resolution is increased, the UHDTV requires a transmission technology to support very high data transf...The goal of an UHDTV is to broadcast digital video contents which is 16 times the pixel resolution of HDTV. As the resolution is increased, the UHDTV requires a transmission technology to support very high data transfer rate. In this paper, we propose two out-of-band protocols to transmit UHDTV contents in a CATV network: an OOB-based protocol and a DSG-based protocol. The former may be a short term solution which is well suitable for a traditional CATV network and the letter may be a long term solution which is adoptable for a CATV network equipped with DOCSIS functionalities. In order to transfer 200 Mbps UHDTV contents, proposed protocols use a channel bonding mechanism which combines several QAM channels. We propose CATV network architectures to support an UHDTV service with a channel bonding mechanism, and design the format of messages to share the information of bonded channels between a headend and a STB. We develop an OPNET simulator and ascertain successful transmission of UHDTV contents.展开更多
This paper presents the network service model and protocol model, and gives a brief introduction to a high level Petri net called EPr/TN net system, which serves as the formal specification tool for network protocol....This paper presents the network service model and protocol model, and gives a brief introduction to a high level Petri net called EPr/TN net system, which serves as the formal specification tool for network protocol. Finally, the general methods for the展开更多
A proactive routing protocol CL-OLSR （cross-layer based optimized link state routing） by using a brand-new routing metric CLM （cross-layer metric） is proposed. CL-OLSR takes into account four link quality impact f...A proactive routing protocol CL-OLSR （cross-layer based optimized link state routing） by using a brand-new routing metric CLM （cross-layer metric） is proposed. CL-OLSR takes into account four link quality impact factors in route calculation through the cross-layer operation mechanism： the node available bandwidth, the node load, the link delivery rate, and the link interference, and thus the effect of route selection is optimized greatly. The simulation results show that the proposed CL-OLSR protocol can not only improve the network throughput to a large extent, but also reduce the end-to-end delay, while achieving load balance route results.展开更多
Channel characterization and modeling are fundamental to communication system design,development,testing,and deployment.As the innate digital twins of wireless channels,channel models replicate real-world channel beha...Channel characterization and modeling are fundamental to communication system design,development,testing,and deployment.As the innate digital twins of wireless channels,channel models replicate real-world channel behaviors,e.g.,large-scale/small-scale fading,spatio-temporal-frequency non-stationarity,through mathematical and data-driven methods.This enables simulation-based validation across system development stages—from protocol design to network optimization-without costly physical testing.展开更多
随着列车通信技术的发展,列车控制网络的环境愈发复杂,车载设备对网络带宽和网络拓扑复杂度的要求愈发严格,列车互联网的物理层载体逐渐从串行通信总线网过渡到了以太网。为了保证以太网协议栈在列车互联网中的正常运行,结合列车互联网...随着列车通信技术的发展,列车控制网络的环境愈发复杂,车载设备对网络带宽和网络拓扑复杂度的要求愈发严格,列车互联网的物理层载体逐渐从串行通信总线网过渡到了以太网。为了保证以太网协议栈在列车互联网中的正常运行,结合列车互联网的独特需求,列车通信网络(train communication network,TCN)联盟提出了列车实时数据协议(train real-time data protocol,TRDP),现已成为车载设备数据传输中不可或缺的重要一环。然而,在引入以太网架构的同时,传统计算机网络面临的安全风险也被带入了列车通信网络中。架构在以太网之上的TRDP,缺乏有效的安全防护机制,面临着恶意攻击、数据泄露、拒绝服务等一系列风险。在TRDP的础上,分析了TRDP消息数据、过程数据两种协议模式的区别和安全需求,结合列车互联网的实际情况,选取合适的加密协议,改进了协议细节,设计了基于加密协议的安全防护机制。并在此基础上搭建了一个模型系统,系统展示了如何将这些关键的密码技术组合起来,构建一个安全的列车互联网信息系统,并证明了系统在保证协议安全性的情况下,能够满足列车互联网对TRDP的性能需求。展开更多
文摘This work aims to examine the vulnerabilities and threats in the applications of intelligent transport systems,especially collision avoidance protocols.It focuses on achieving the availability of network communication among traveling vehicles.Finally,it aims to find a secure solution to prevent blackhole attacks on vehicular network communications.The proposed solution relies on authenticating vehicles by joining a blockchain network.This technology provides identification information and receives cryptography keys.Moreover,the ad hoc on-demand distance vector(AODV)protocol is used for route discovery and ensuring reliable node communication.The system activates an adaptive mode for monitoring communications and continually adjusts trust scores based on packet delivery performance.From the experimental study,we can infer that the proposed protocol has successfully detected and prevented blackhole attacks for different numbers of simulated vehicles and at different traveling speeds.This reduces accident rates by 60%and increases the packet delivery ratio and the throughput of the connecting network by 40%and 20%,respectively.However,extra overheads in delay and memory are required to create and initialize the blockchain network.
文摘The goal of an UHDTV is to broadcast digital video contents which is 16 times the pixel resolution of HDTV. As the resolution is increased, the UHDTV requires a transmission technology to support very high data transfer rate. In this paper, we propose two out-of-band protocols to transmit UHDTV contents in a CATV network: an OOB-based protocol and a DSG-based protocol. The former may be a short term solution which is well suitable for a traditional CATV network and the letter may be a long term solution which is adoptable for a CATV network equipped with DOCSIS functionalities. In order to transfer 200 Mbps UHDTV contents, proposed protocols use a channel bonding mechanism which combines several QAM channels. We propose CATV network architectures to support an UHDTV service with a channel bonding mechanism, and design the format of messages to share the information of bonded channels between a headend and a STB. We develop an OPNET simulator and ascertain successful transmission of UHDTV contents.
文摘This paper presents the network service model and protocol model, and gives a brief introduction to a high level Petri net called EPr/TN net system, which serves as the formal specification tool for network protocol. Finally, the general methods for the
基金supported by the Fundamental Research Funds for the Central Universities under Grant No.ZYGX2009j006Foundation of Science & Technology Department of Sichuan Province under Grant No.2011GZ0192
文摘A proactive routing protocol CL-OLSR （cross-layer based optimized link state routing） by using a brand-new routing metric CLM （cross-layer metric） is proposed. CL-OLSR takes into account four link quality impact factors in route calculation through the cross-layer operation mechanism： the node available bandwidth, the node load, the link delivery rate, and the link interference, and thus the effect of route selection is optimized greatly. The simulation results show that the proposed CL-OLSR protocol can not only improve the network throughput to a large extent, but also reduce the end-to-end delay, while achieving load balance route results.
文摘Channel characterization and modeling are fundamental to communication system design,development,testing,and deployment.As the innate digital twins of wireless channels,channel models replicate real-world channel behaviors,e.g.,large-scale/small-scale fading,spatio-temporal-frequency non-stationarity,through mathematical and data-driven methods.This enables simulation-based validation across system development stages—from protocol design to network optimization-without costly physical testing.
文摘随着列车通信技术的发展,列车控制网络的环境愈发复杂,车载设备对网络带宽和网络拓扑复杂度的要求愈发严格,列车互联网的物理层载体逐渐从串行通信总线网过渡到了以太网。为了保证以太网协议栈在列车互联网中的正常运行,结合列车互联网的独特需求,列车通信网络(train communication network,TCN)联盟提出了列车实时数据协议(train real-time data protocol,TRDP),现已成为车载设备数据传输中不可或缺的重要一环。然而,在引入以太网架构的同时,传统计算机网络面临的安全风险也被带入了列车通信网络中。架构在以太网之上的TRDP,缺乏有效的安全防护机制,面临着恶意攻击、数据泄露、拒绝服务等一系列风险。在TRDP的础上,分析了TRDP消息数据、过程数据两种协议模式的区别和安全需求,结合列车互联网的实际情况,选取合适的加密协议,改进了协议细节,设计了基于加密协议的安全防护机制。并在此基础上搭建了一个模型系统,系统展示了如何将这些关键的密码技术组合起来,构建一个安全的列车互联网信息系统,并证明了系统在保证协议安全性的情况下,能够满足列车互联网对TRDP的性能需求。
