Internet上随着网络的不断发展和用户的要求越来越高,以为用户提供更高服务质量(Quality of Service,QoS)为目标的研究越来越重要。而强壮的网络拥塞控制是保障用户服务质量的基础。"随机早期检测算法"(Random Early Detectio...Internet上随着网络的不断发展和用户的要求越来越高,以为用户提供更高服务质量(Quality of Service,QoS)为目标的研究越来越重要。而强壮的网络拥塞控制是保障用户服务质量的基础。"随机早期检测算法"(Random Early Detection,RED)[1],由于其在实际应用的广泛,成为研究热点。文章首先探讨远端流和近端流在在传输过程中的不公平性和链路资源利用情况,在此基础上提出路由器将网络中的流分为远近两种区分对待,改进RED算法以提高链路资源的利用率和流在传输过程中的公平性。展开更多
The bandwidth resources allocation strategies of the existing Internet of Vehicles(IoV) are mainly base on the communication architecture of the traditional 802.11 x in the wireless local area network(WLAN). The tradi...The bandwidth resources allocation strategies of the existing Internet of Vehicles(IoV) are mainly base on the communication architecture of the traditional 802.11 x in the wireless local area network(WLAN). The traditional communication architecture of IoV will easily cause significant delay and low Packet Delivery Ratio(PDR) for disseminating critical security beacons under the condition of high-speed movement, distance-varying communication, and mixed traffic. This paper proposes a novel bandwidth-link resources cooperative allocation strategy to achieve better communication performance under the road conditions of intelligent transportation systems(ITS). Firstly, in traffic scenarios, based on the characteristic to predict the relative position of the mobile transceivers, a strategy is developed to cooperate on the mobile cellular network and the Dedicated Short-Range Communications(DSRC). Secondly, by adopting the general network simulator NS3, the dedicated mobile channel models that are suitable for the data interaction of ITS, is applied to confirm the feasibility and reliability of the strategy. Finally, by the simulation, comparison, and analysis of some critical performance parame-ters, we conclude that the novel strategy does not only reduce the system delay but also improve the other communication performance indicators, such as the PDR and communication capacity.展开更多
随着超高清、增强现实/虚拟现实和千兆宽带接入进入千家万户,原有的混合光纤同轴电缆(Hybrid Fiber Coax,HFC)有线电视网络已不能有效承载各类新兴业务。同时,原有网络在运营维护、设备功耗、安全传输等方面与光纤到户(Fibre To The Hom...随着超高清、增强现实/虚拟现实和千兆宽带接入进入千家万户,原有的混合光纤同轴电缆(Hybrid Fiber Coax,HFC)有线电视网络已不能有效承载各类新兴业务。同时,原有网络在运营维护、设备功耗、安全传输等方面与光纤到户(Fibre To The Home,FTTH)网络相比,存在一定劣势,因此,将原HFC网络升级改造为FTTH网络是必然趋势。基于此,以曲靖市麒麟区城区有线电视FTTH网络升级改造项目为例,对有线电视FTTH网络升级改造的规划建设、安全管理以及后续运营维护等方面进行探讨。展开更多
文摘Internet上随着网络的不断发展和用户的要求越来越高,以为用户提供更高服务质量(Quality of Service,QoS)为目标的研究越来越重要。而强壮的网络拥塞控制是保障用户服务质量的基础。"随机早期检测算法"(Random Early Detection,RED)[1],由于其在实际应用的广泛,成为研究热点。文章首先探讨远端流和近端流在在传输过程中的不公平性和链路资源利用情况,在此基础上提出路由器将网络中的流分为远近两种区分对待,改进RED算法以提高链路资源的利用率和流在传输过程中的公平性。
基金supported in part by the National Natural Science Foundation of China (No.61573171)the Major Information Projects of State Ministry of Transportation (No.2013-364-836-900)
文摘The bandwidth resources allocation strategies of the existing Internet of Vehicles(IoV) are mainly base on the communication architecture of the traditional 802.11 x in the wireless local area network(WLAN). The traditional communication architecture of IoV will easily cause significant delay and low Packet Delivery Ratio(PDR) for disseminating critical security beacons under the condition of high-speed movement, distance-varying communication, and mixed traffic. This paper proposes a novel bandwidth-link resources cooperative allocation strategy to achieve better communication performance under the road conditions of intelligent transportation systems(ITS). Firstly, in traffic scenarios, based on the characteristic to predict the relative position of the mobile transceivers, a strategy is developed to cooperate on the mobile cellular network and the Dedicated Short-Range Communications(DSRC). Secondly, by adopting the general network simulator NS3, the dedicated mobile channel models that are suitable for the data interaction of ITS, is applied to confirm the feasibility and reliability of the strategy. Finally, by the simulation, comparison, and analysis of some critical performance parame-ters, we conclude that the novel strategy does not only reduce the system delay but also improve the other communication performance indicators, such as the PDR and communication capacity.
文摘随着超高清、增强现实/虚拟现实和千兆宽带接入进入千家万户,原有的混合光纤同轴电缆(Hybrid Fiber Coax,HFC)有线电视网络已不能有效承载各类新兴业务。同时,原有网络在运营维护、设备功耗、安全传输等方面与光纤到户(Fibre To The Home,FTTH)网络相比,存在一定劣势,因此,将原HFC网络升级改造为FTTH网络是必然趋势。基于此,以曲靖市麒麟区城区有线电视FTTH网络升级改造项目为例,对有线电视FTTH网络升级改造的规划建设、安全管理以及后续运营维护等方面进行探讨。
