A mode of process/thread communication between QNX and WINDOWS operating systems in isomerous computers is described. It is proved in practice to be an entirely feasible mode with high efficiency and reliability. A so...A mode of process/thread communication between QNX and WINDOWS operating systems in isomerous computers is described. It is proved in practice to be an entirely feasible mode with high efficiency and reliability. A socket created by Socket API is used to communicate between two operating systems.展开更多
Transmission Control Protocol (TCP) was originally designed for wired networks. Many compatibility problems exist when it is applied to wireless environments, and hence it needs to undergo modifications. Currently, th...Transmission Control Protocol (TCP) was originally designed for wired networks. Many compatibility problems exist when it is applied to wireless environments, and hence it needs to undergo modifications. Currently, there are several TCP performance enhancement techniques for application of TCP in wireless environments, but all of them conflict with IPsec. This paper not only analyzes these conflicts, but also proposes 4 solutions: replacing IPsec with Transport Layer Security/Secure Socket Layer (TLS/SSL) protocol, adopting the extended Encapsulating Security Payload (ESP) protocol, segmenting the TCP route, and modifying the end-to-end protection mode of IPsec. It also presents their strengths and weaknesses.展开更多
随着网际互连协议(Internet Protocol,IP)网络在广播电视信号传输中的广泛应用,网络拥塞和信号质量下降等问题日益突出。针对上述挑战,深入分析IP组播、服务质量(Quality of Service,QoS)机制及网络编码等关键技术,在此基础上提出一种...随着网际互连协议(Internet Protocol,IP)网络在广播电视信号传输中的广泛应用,网络拥塞和信号质量下降等问题日益突出。针对上述挑战,深入分析IP组播、服务质量(Quality of Service,QoS)机制及网络编码等关键技术,在此基础上提出一种改进的自适应比特率算法。该算法结合网络状态感知和内容复杂度评估,可实现传输参数的动态调整。通过在模拟网络环境中进行大规模实验,结果表明所提算法在带宽利用率、传输时延及画质方面均有显著提升。此次研究成果为IP网络下广播电视信号的高效传输提供了新的技术方案。展开更多
随着空间通信系统的发展,CCSDS建议逐渐成为了空间通信的标准,特别是IP over CCSDS Space Links红皮书提出以后,IP已经成为空间信息系统的标准上层应用。提出了一种天地通信系统CCSDS加速网关的设计实现方法,介绍了基于加速网关的天地...随着空间通信系统的发展,CCSDS建议逐渐成为了空间通信的标准,特别是IP over CCSDS Space Links红皮书提出以后,IP已经成为空间信息系统的标准上层应用。提出了一种天地通信系统CCSDS加速网关的设计实现方法,介绍了基于加速网关的天地通信网络结构,描述了其关键技术实现,最后对提出的设计实现方法在OPNET中进行了仿真验证。OPNET仿真结果表明,该技术大大提高了TCP应用在空间链路上的传输效率,而且在多连接共享带宽时保持了较好的公平性。展开更多
基金The project supported by the National Meg-science Engineering project of the Chinese Government
文摘A mode of process/thread communication between QNX and WINDOWS operating systems in isomerous computers is described. It is proved in practice to be an entirely feasible mode with high efficiency and reliability. A socket created by Socket API is used to communicate between two operating systems.
文摘Transmission Control Protocol (TCP) was originally designed for wired networks. Many compatibility problems exist when it is applied to wireless environments, and hence it needs to undergo modifications. Currently, there are several TCP performance enhancement techniques for application of TCP in wireless environments, but all of them conflict with IPsec. This paper not only analyzes these conflicts, but also proposes 4 solutions: replacing IPsec with Transport Layer Security/Secure Socket Layer (TLS/SSL) protocol, adopting the extended Encapsulating Security Payload (ESP) protocol, segmenting the TCP route, and modifying the end-to-end protection mode of IPsec. It also presents their strengths and weaknesses.
文摘随着网际互连协议(Internet Protocol,IP)网络在广播电视信号传输中的广泛应用,网络拥塞和信号质量下降等问题日益突出。针对上述挑战,深入分析IP组播、服务质量(Quality of Service,QoS)机制及网络编码等关键技术,在此基础上提出一种改进的自适应比特率算法。该算法结合网络状态感知和内容复杂度评估,可实现传输参数的动态调整。通过在模拟网络环境中进行大规模实验,结果表明所提算法在带宽利用率、传输时延及画质方面均有显著提升。此次研究成果为IP网络下广播电视信号的高效传输提供了新的技术方案。
文摘随着空间通信系统的发展,CCSDS建议逐渐成为了空间通信的标准,特别是IP over CCSDS Space Links红皮书提出以后,IP已经成为空间信息系统的标准上层应用。提出了一种天地通信系统CCSDS加速网关的设计实现方法,介绍了基于加速网关的天地通信网络结构,描述了其关键技术实现,最后对提出的设计实现方法在OPNET中进行了仿真验证。OPNET仿真结果表明,该技术大大提高了TCP应用在空间链路上的传输效率,而且在多连接共享带宽时保持了较好的公平性。
