This paper introduces architectures of two types optical packet switched metropolitan area networks and their media access control protocols. We have designed related network simulation systems. With these simulation...This paper introduces architectures of two types optical packet switched metropolitan area networks and their media access control protocols. We have designed related network simulation systems. With these simulation systems, the characteristics and performance of the two MANs can be achieved.展开更多
In this paper a frequency offset estimation technique for Wireless Local Area and Wireless Metropolitan Ar- ea Networks is presented. For frequency offset estimation, we have applied a low-complexity frequency offset ...In this paper a frequency offset estimation technique for Wireless Local Area and Wireless Metropolitan Ar- ea Networks is presented. For frequency offset estimation, we have applied a low-complexity frequency offset estimator for simple AWGN channels to fading channels for MIMO-OFDM systems. Simulation results have shown that the performance of the proposed estimator is better than the low complexity frequency offset estimator designed for AWGN channels.展开更多
This paper aims at analyzing the security issues that lie in the application layer (AL) protocols when users connect to the Internet via a wireless local area network (WLAN) through an access point. When adversaries l...This paper aims at analyzing the security issues that lie in the application layer (AL) protocols when users connect to the Internet via a wireless local area network (WLAN) through an access point. When adversaries launch deauthentication flood attacks cutting users' connection, the connection managers will automatically research the last access point's extended service set identifier (ESSID) and then re-establish connection. However, such re-connection can lead the users to a fake access point with the same ESSID set by attackers. As the attackers hide behind users' access points, they can pass AL's authentication and security schemes, e.g. secure socket layer (SSL). We have proved that they can even spy on users' account details, passwords, data and privacy.展开更多
面向5G和云网融合业务的发展,传统互联网协议(Internet Protocol,IP)城域网络(Metropolitan Area Network,MAN)固移分离承载、网络设备与功能紧耦合的方式已难以满足云网融合差异化承载、业务快速自动开通等需求,因此新型城域网的发展...面向5G和云网融合业务的发展,传统互联网协议(Internet Protocol,IP)城域网络(Metropolitan Area Network,MAN)固移分离承载、网络设备与功能紧耦合的方式已难以满足云网融合差异化承载、业务快速自动开通等需求,因此新型城域网的发展成为必然。主要分析城域网的发展现状、存在问题以及业务发展需求等内容,从网络架构、新设备及新技术等方面研究新型城域网的建设思路。展开更多
分析当前新一轮科技革命和产业变革背景下城域网(Metropolitan Area Network,MAN)中不同用户的特征和对网络的需求,给出了通过引入边缘云将部分计算能力下沉到更靠近用户的地方,提供网络的灵活定制和确定性服务保障,满足不同场景和用户...分析当前新一轮科技革命和产业变革背景下城域网(Metropolitan Area Network,MAN)中不同用户的特征和对网络的需求,给出了通过引入边缘云将部分计算能力下沉到更靠近用户的地方,提供网络的灵活定制和确定性服务保障,满足不同场景和用户需求的建议。通过探讨当前城域网的现状,指出在现网引入边缘云时存在的主要问题,提出一种利用光交叉连接技术构建波长资源池来实现光电协同、灵活弹性连接的面向云网融合的全光城域网架构,最后介绍了基于此构架的边缘云业务承载方案。展开更多
文摘This paper introduces architectures of two types optical packet switched metropolitan area networks and their media access control protocols. We have designed related network simulation systems. With these simulation systems, the characteristics and performance of the two MANs can be achieved.
文摘In this paper a frequency offset estimation technique for Wireless Local Area and Wireless Metropolitan Ar- ea Networks is presented. For frequency offset estimation, we have applied a low-complexity frequency offset estimator for simple AWGN channels to fading channels for MIMO-OFDM systems. Simulation results have shown that the performance of the proposed estimator is better than the low complexity frequency offset estimator designed for AWGN channels.
基金the National Science Council (No. NSC-99-2219-E-033-001)the Foundation of the Chung Yuan Christian University (1004) (No. CYCU-EECS.9801)
文摘This paper aims at analyzing the security issues that lie in the application layer (AL) protocols when users connect to the Internet via a wireless local area network (WLAN) through an access point. When adversaries launch deauthentication flood attacks cutting users' connection, the connection managers will automatically research the last access point's extended service set identifier (ESSID) and then re-establish connection. However, such re-connection can lead the users to a fake access point with the same ESSID set by attackers. As the attackers hide behind users' access points, they can pass AL's authentication and security schemes, e.g. secure socket layer (SSL). We have proved that they can even spy on users' account details, passwords, data and privacy.
文摘面向5G和云网融合业务的发展,传统互联网协议(Internet Protocol,IP)城域网络(Metropolitan Area Network,MAN)固移分离承载、网络设备与功能紧耦合的方式已难以满足云网融合差异化承载、业务快速自动开通等需求,因此新型城域网的发展成为必然。主要分析城域网的发展现状、存在问题以及业务发展需求等内容,从网络架构、新设备及新技术等方面研究新型城域网的建设思路。
文摘分析当前新一轮科技革命和产业变革背景下城域网(Metropolitan Area Network,MAN)中不同用户的特征和对网络的需求,给出了通过引入边缘云将部分计算能力下沉到更靠近用户的地方,提供网络的灵活定制和确定性服务保障,满足不同场景和用户需求的建议。通过探讨当前城域网的现状,指出在现网引入边缘云时存在的主要问题,提出一种利用光交叉连接技术构建波长资源池来实现光电协同、灵活弹性连接的面向云网融合的全光城域网架构,最后介绍了基于此构架的边缘云业务承载方案。
文摘为了有效克服传统流量监测方法仅对数据包进行传输层以下协议进行分析而不能识别P2P(Peer-to-Peer)应用的问题,分析了远程网络监控(RMON:Remote Network Monitoring)、xFlow和探针等流量监控方法的特点及适用情况。并在城域网接入层、汇聚层和城域网(MAN:Metropolitan Area Network)出口3个层面部署探针进行流量监测和分析,获得了完整的流量分布模型。实验表明,通过探针方式网络流量进行分析是全面而有效的。
