Vehicular ad-hoc networks （VANETs） are a significant field in the intelligent transportation system （ITS） for improving road security. The interaction among the vehicles is enclosed under VANETs. Many experiments ...Vehicular ad-hoc networks （VANETs） are a significant field in the intelligent transportation system （ITS） for improving road security. The interaction among the vehicles is enclosed under VANETs. Many experiments have been performed in the region of VANET improvement. A familiar challenge that occurs is obtaining various constrained quality of service （QoS） metrics. For resolving this issue, this study obtains a cost design for the vehicle routing issue by focusing on the QoS metrics such as collision, travel cost, awareness, and congestion. The awareness of QoS is fuzzified into a price design that comprises the entire cost of routing. As the genetic algorithm （GA） endures from the most significant challenges such as complexity, unassisted issues in mutation, detecting slow convergence, global maxima, multifaceted features under genetic coding, and better fitting, the currently established lion algorithm （LA） is employed. The computation is analyzed by deploying three well-known studies such as cost analysis, convergence analysis, and complexity investigations. A numerical analysis with quantitative outcome has also been studied based on the obtained correlation analysis among various cost functions. It is found that LA performs better than GA with a reduction in complexity and routing cost.展开更多
针对车载自组织网络(Vehicular Ad hoc Network,VANET)中车辆跨密码系统通信过程中的隐私泄露问题,提出了一种格基异构签密方案.首先,方案实现了无证书密码系统(Certificateless Cryptosystem,CLC)的车辆与基于身份密码系统(Identity-Ba...针对车载自组织网络(Vehicular Ad hoc Network,VANET)中车辆跨密码系统通信过程中的隐私泄露问题,提出了一种格基异构签密方案.首先,方案实现了无证书密码系统(Certificateless Cryptosystem,CLC)的车辆与基于身份密码系统(Identity-Based Cryptosystem,IBC)的车辆相互通信;其次利用签密的机密性和可认证性防止车辆用户在跨密码系统通信过程中发生隐私泄露,并实现了接收方对消息完整性以及发送方身份合法性的认证;最后在随机预言机模型下证明了方案在适应性选择密文攻击下具有不可区分性(Indistinguishability against adaptive Chosen Cipher Text Attack,IND-CCA2),在适应性选择消息攻击下具有存在性不可伪造性(Existential Unforgeability against adaptive Chosen Messages Attack,EUF-CMA).性能分析表明,与其他方案相比,本文方案在计算开销、通信开销和安全性方面具有一定优势,适用于车辆跨密码系统通信的场景.展开更多
车载自组网(vehicular ad hoc network,VANET)中的分布式TDMA方法通常多出没有被节点利用的空闲时隙,未能充分利用无线信道资源,且不能避免由于信道条件差所导致的丢包现象.与此同时,协助通信近年来引起了学术界和工业界的广泛关注,该...车载自组网(vehicular ad hoc network,VANET)中的分布式TDMA方法通常多出没有被节点利用的空闲时隙,未能充分利用无线信道资源,且不能避免由于信道条件差所导致的丢包现象.与此同时,协助通信近年来引起了学术界和工业界的广泛关注,该方法利用了无线信道的广播特性,能够有效地修复信道,提高无线通信的可靠性.针对VANET应用场合,提出了一种MAC层数据协助重发方法,即协助分布式TDMA方法(cooperative distributed TDMA,Co-DTDMA).在Co-DTDMA中,如果源节点未成功发送数据,则附近的邻居节点利用未分配的空闲时隙协助重发源节点数据.与传统的协助通信方法不同,Co-DTDMA中的所有操作都以分布式方式进行,不依赖任何中心控制节点,因而适应于VANET应用场合.此外,Co-DTDMA仅利用未分配的空闲时隙协助重发数据,不影响网络中的正常数据传输.理论分析和仿真实验表明:Co-DTDMA显著地提高了数据成功接收概率,降低了数据传输时延.展开更多
车载自组网(Vehicular Ad hoc Network,VANET)信道建模对车辆间通信具有重要意义。分析了2.4GHz通信频段两车在武汉市内通信实测丢包率数据,提出了信道丢包率模型FVPM(Fresnel theory based VANET Propagation Model),考虑了实际传输中...车载自组网(Vehicular Ad hoc Network,VANET)信道建模对车辆间通信具有重要意义。分析了2.4GHz通信频段两车在武汉市内通信实测丢包率数据,提出了信道丢包率模型FVPM(Fresnel theory based VANET Propagation Model),考虑了实际传输中车辆和街道环境对丢包率影响,以及丢包率随距离变化的概率分布。最后的模型检验结果表明,FVPM比经典Two-Ray、Shadowing模型更加准确地描述了VANET信道特征,对VANET信道研究具有借鉴意义。展开更多
文摘Vehicular ad-hoc networks （VANETs） are a significant field in the intelligent transportation system （ITS） for improving road security. The interaction among the vehicles is enclosed under VANETs. Many experiments have been performed in the region of VANET improvement. A familiar challenge that occurs is obtaining various constrained quality of service （QoS） metrics. For resolving this issue, this study obtains a cost design for the vehicle routing issue by focusing on the QoS metrics such as collision, travel cost, awareness, and congestion. The awareness of QoS is fuzzified into a price design that comprises the entire cost of routing. As the genetic algorithm （GA） endures from the most significant challenges such as complexity, unassisted issues in mutation, detecting slow convergence, global maxima, multifaceted features under genetic coding, and better fitting, the currently established lion algorithm （LA） is employed. The computation is analyzed by deploying three well-known studies such as cost analysis, convergence analysis, and complexity investigations. A numerical analysis with quantitative outcome has also been studied based on the obtained correlation analysis among various cost functions. It is found that LA performs better than GA with a reduction in complexity and routing cost.
文摘针对车载自组织网络(Vehicular Ad hoc Network,VANET)中车辆跨密码系统通信过程中的隐私泄露问题,提出了一种格基异构签密方案.首先,方案实现了无证书密码系统(Certificateless Cryptosystem,CLC)的车辆与基于身份密码系统(Identity-Based Cryptosystem,IBC)的车辆相互通信;其次利用签密的机密性和可认证性防止车辆用户在跨密码系统通信过程中发生隐私泄露,并实现了接收方对消息完整性以及发送方身份合法性的认证;最后在随机预言机模型下证明了方案在适应性选择密文攻击下具有不可区分性(Indistinguishability against adaptive Chosen Cipher Text Attack,IND-CCA2),在适应性选择消息攻击下具有存在性不可伪造性(Existential Unforgeability against adaptive Chosen Messages Attack,EUF-CMA).性能分析表明,与其他方案相比,本文方案在计算开销、通信开销和安全性方面具有一定优势,适用于车辆跨密码系统通信的场景.
文摘车载自组网(vehicular ad hoc network,VANET)中的分布式TDMA方法通常多出没有被节点利用的空闲时隙,未能充分利用无线信道资源,且不能避免由于信道条件差所导致的丢包现象.与此同时,协助通信近年来引起了学术界和工业界的广泛关注,该方法利用了无线信道的广播特性,能够有效地修复信道,提高无线通信的可靠性.针对VANET应用场合,提出了一种MAC层数据协助重发方法,即协助分布式TDMA方法(cooperative distributed TDMA,Co-DTDMA).在Co-DTDMA中,如果源节点未成功发送数据,则附近的邻居节点利用未分配的空闲时隙协助重发源节点数据.与传统的协助通信方法不同,Co-DTDMA中的所有操作都以分布式方式进行,不依赖任何中心控制节点,因而适应于VANET应用场合.此外,Co-DTDMA仅利用未分配的空闲时隙协助重发数据,不影响网络中的正常数据传输.理论分析和仿真实验表明:Co-DTDMA显著地提高了数据成功接收概率,降低了数据传输时延.
文摘车载自组网(Vehicular Ad hoc Network,VANET)信道建模对车辆间通信具有重要意义。分析了2.4GHz通信频段两车在武汉市内通信实测丢包率数据,提出了信道丢包率模型FVPM(Fresnel theory based VANET Propagation Model),考虑了实际传输中车辆和街道环境对丢包率影响,以及丢包率随距离变化的概率分布。最后的模型检验结果表明,FVPM比经典Two-Ray、Shadowing模型更加准确地描述了VANET信道特征,对VANET信道研究具有借鉴意义。
