There is a lack of appropriate guidelines for realistic user traces, mobility models, routing protocols, considerations of real-life challenges, etc. for general-purpose mobile ad hoc networks （MANET）. In this paper...There is a lack of appropriate guidelines for realistic user traces, mobility models, routing protocols, considerations of real-life challenges, etc. for general-purpose mobile ad hoc networks （MANET）. In this paper, four laptops are used in an open field environment in four scenarios to evaluate the performances of Internet control message protocol （ICMP） based ping and transmission control protocol （TCP） based streaming video applications using optimised link state routing （OLSR） implementation in an IEEE 802.11g wireless network. Corresponding simulations are developed in Network Simulator ns-2 by setting simulation parameters according to the real experiments. Difficulties faced to regenerate real-life scenarios have been discussed and the gaps between reality and simulation are identified. A setup guideline to produce realistic simulation results has been established.展开更多
物联网(Internet of Things,IoT)对广域通信提出了高效、可靠、低功耗的要求,因此窄带物联网(Narrow Band Internet of Things,NB-IoT)技术应运而生,其通过优化网络升级和降低成本,实现了广泛分布式的设备连接。可靠数据报协议(Reliable...物联网(Internet of Things,IoT)对广域通信提出了高效、可靠、低功耗的要求,因此窄带物联网(Narrow Band Internet of Things,NB-IoT)技术应运而生,其通过优化网络升级和降低成本,实现了广泛分布式的设备连接。可靠数据报协议(Reliable User Datagram Protocol,RUDP)对传统UDP进行增强,旨在提供低延迟通信和可靠保证,其中快速可靠传输协议(KCP)因其轻量和灵活被广泛采用。为满足窄带物联网在分布式复杂场景下的传输需求,本文优化了KCP传输逻辑,设计发布-订阅、请求-响应两种模式满足应用层需求,并引入了心跳检测和选举机制,以提升系统的稳定性和容错性。展开更多
随着高清和超高清直播需求的增长,传统编码技术在压缩效率和传输质量方面逐渐显现出局限性。针对这一问题,提出基于高效视频编码(High Efficiency Video Coding,HEVC)技术的优化策略,以期改善直播电视信号的压缩效率、传输延迟及画质清...随着高清和超高清直播需求的增长,传统编码技术在压缩效率和传输质量方面逐渐显现出局限性。针对这一问题,提出基于高效视频编码(High Efficiency Video Coding,HEVC)技术的优化策略,以期改善直播电视信号的压缩效率、传输延迟及画质清晰度。实验结果表明,HEVC技术结合快速用户数据报协议互联网连接(Quick User Datagram Protocol Internet Connections,QUIC)协议和硬件加速技术,可显著提高高分辨率场景下的信号稳定性和实时性。展开更多
分布式控制是智能配电网实现广域保护、控制应用的重要方式,报文的实时性是影响分布式控制性能的关键因素。文中在分析配电网分布式控制应用对通信的要求基础上,对现有的快速报文传输方式进行了比较,提出了基于用户数据报协议(UDP),用...分布式控制是智能配电网实现广域保护、控制应用的重要方式,报文的实时性是影响分布式控制性能的关键因素。文中在分析配电网分布式控制应用对通信的要求基础上,对现有的快速报文传输方式进行了比较,提出了基于用户数据报协议(UDP),用通用面向对象变电站事件(GOOSE)机制传输实时报文(GOOSE over UDP)的方案,可实现快速报文在广域网传输。通过试验平台对该方案的传输性能进行了测试,测得配电终端之间传输延时最大不超过10 ms,满足配电网分布式控制应用的需求。展开更多
文摘There is a lack of appropriate guidelines for realistic user traces, mobility models, routing protocols, considerations of real-life challenges, etc. for general-purpose mobile ad hoc networks （MANET）. In this paper, four laptops are used in an open field environment in four scenarios to evaluate the performances of Internet control message protocol （ICMP） based ping and transmission control protocol （TCP） based streaming video applications using optimised link state routing （OLSR） implementation in an IEEE 802.11g wireless network. Corresponding simulations are developed in Network Simulator ns-2 by setting simulation parameters according to the real experiments. Difficulties faced to regenerate real-life scenarios have been discussed and the gaps between reality and simulation are identified. A setup guideline to produce realistic simulation results has been established.
文摘物联网(Internet of Things,IoT)对广域通信提出了高效、可靠、低功耗的要求,因此窄带物联网(Narrow Band Internet of Things,NB-IoT)技术应运而生,其通过优化网络升级和降低成本,实现了广泛分布式的设备连接。可靠数据报协议(Reliable User Datagram Protocol,RUDP)对传统UDP进行增强,旨在提供低延迟通信和可靠保证,其中快速可靠传输协议(KCP)因其轻量和灵活被广泛采用。为满足窄带物联网在分布式复杂场景下的传输需求,本文优化了KCP传输逻辑,设计发布-订阅、请求-响应两种模式满足应用层需求,并引入了心跳检测和选举机制,以提升系统的稳定性和容错性。
文摘随着高清和超高清直播需求的增长,传统编码技术在压缩效率和传输质量方面逐渐显现出局限性。针对这一问题,提出基于高效视频编码(High Efficiency Video Coding,HEVC)技术的优化策略,以期改善直播电视信号的压缩效率、传输延迟及画质清晰度。实验结果表明,HEVC技术结合快速用户数据报协议互联网连接(Quick User Datagram Protocol Internet Connections,QUIC)协议和硬件加速技术,可显著提高高分辨率场景下的信号稳定性和实时性。
文摘分布式控制是智能配电网实现广域保护、控制应用的重要方式,报文的实时性是影响分布式控制性能的关键因素。文中在分析配电网分布式控制应用对通信的要求基础上,对现有的快速报文传输方式进行了比较,提出了基于用户数据报协议(UDP),用通用面向对象变电站事件(GOOSE)机制传输实时报文(GOOSE over UDP)的方案,可实现快速报文在广域网传输。通过试验平台对该方案的传输性能进行了测试,测得配电终端之间传输延时最大不超过10 ms,满足配电网分布式控制应用的需求。
基金Supported by the National Natural Science Foundation of China under Grant Nos.6047207660673178+3 种基金60434030(国家自然科学基金)the National Grand Fundamental Research973Program of China under Grant No.2006CB303007(国家重点基础研究发展规划(973))the National High-Tech Research and Development Plan of China under Grant.Nos.2006AA01Z2182006AA01Z215(国家高技术研究发展计划(863))
