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1.
介绍了免费的TCP/IP协议栈LWIP开发工具和环境,分析了如何实现LWIP的移植,并给出了一种嵌入式系统与网络互联的新思路。 相似文献
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容错技术广泛应用于各个行业来保证系统的冗余和可靠性。文章在分析比较当前的双机容错系统的性能优缺点后,提出了一种全新的基于“层”模式的双机容错系统解决方案。按照这种模式,可以从链路层到应用层构建一个通用的系统级的双机容错系统。文章对其实现的关键技术进行了阐述。 相似文献
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Frank H. P. Fitzek Martin Reisslein 《International Journal of Communication Systems》2004,17(5):421-435
Video streaming is expected to account for a large portion of the traffic in future networks, including wireless networks. It is widely accepted that the user datagram protocol (UDP) is the preferred transport protocol for video streaming and that the transmission control protocol (TCP) is unsuitable for streaming. The widespread use of UDP, however, has a number of drawbacks, such as unfairness and possible congestion collapse, which are avoided by TCP. In this paper we investigate the use of TCP as the transport layer protocol for streaming video in a multi‐code CDMA cellular wireless system. Our approach is to stabilize the TCP throughput over the wireless links by employing a recently developed simultaneous MAC packet transmission (SMPT) approach at the link layer. We study the capacity, i.e. the number of customers per cell, and the quality of service for streaming video in the uplink direction. Our extensive simulations indicate that streaming over TCP in conjunction with SMPT gives good performance for video encoded in a closed loop, i.e. with rate control. We have also found that TCP is unsuitable (even in conjunction with SMPT) for streaming the more variable open‐loop encoded video. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
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本文对现有的有线电视业务发布系统进行了介绍,指出了现有系统的特点,并结合现有系统的分析提出了一种新型的业务发布架构:基于UCL标引的大规模并行数据广播系统.该系统源自李幼平院士的第五传媒的思想,即结合互联网(第四传媒)和电视广播网(第三传媒)的优点,取数字广播作信道,采用“细水长流”的小通道把网站内容整体推送到家,并以先进、廉价的存储技术整合“两大传媒”,通过家庭机顶盒内“镜像存储”自由取用.它继承前两种传媒的长处,又避免了各自短处,是一种全新的文化工具.这应是未来业务发布系统的方向. 相似文献
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Optical packet assembly is a key function to support inter-working between TCP/IP networks and optical packet-switched networks.
It is characterized by the assembly delay and by the segment aggregation needed to form an optical packet. These counter-balancing
aspects depend on several environment variables, such as the TCP parameters, the access link speed, the optical packet size
whose effects are studied in this paper. Performance evaluations are obtained by extensive simulations in terms of send rate
of TCP flows, fairness, efficiency, and assembly delay. Some guidelines in the design of optical packets that take into account
the results presented are given. 相似文献
8.
Navid Ehsan Mingyan Liu Roderick J. Ragland 《International Journal of Communication Systems》2003,16(6):513-534
Performance enhancing proxies (PEPs) are widely used to improve the performance of TCP over high delay‐bandwidth product links and links with high error probability. In this paper we analyse the performance of using TCP connection splitting in combination with web caching via traces obtained from a commercial satellite system. We examine the resulting performance gain under different scenarios, including the effect of caching, congestion, random loss and file sizes. We show, via analysing our measurements, that the performance gain from using splitting is highly sensitive to random losses and the number of simultaneous connections, and that such sensitivity is alleviated by caching. On the other hand, the use of a splitting proxy enhances the value of web caching in that cache hits result in much more significant performance improvement over cache misses when TCP splitting is used. We also compare the performance of using different versions of HTTP in such a system. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
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A. A. Kherani B. J. Prabhu K. E. Avrachenkov E. Altman 《Telecommunication Systems》2005,30(4):321-350
We study an Adaptive Window Protocol (AWP) with general increase and decrease profiles in the presence of window dependent
random losses. We derive a steady-state Kolmogorov equation, and then obtain its solution in analytic form for particular
TCP versions proposed for high speed networks, such as Scalable TCP and HighSpeed TCP. We also relate window evolution under
an AWP to workload process in queueing systems; this observation gives us a way to compare various AWP protocols. 相似文献