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文章概述了CDMA系统内无线资源管理包含的主要内容,以WCDMA的上、下行的准入控制算法为例,分析了无线资源管理的算法对网络优化的影响。 相似文献
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大数据平台的底层存储系统往往无法匹配上层计算应用的读写性能,而一个设计良好的分布式缓存系统将缩小CPU密集型应用和IO密集型应用之间不匹配的性能差距。设计的面向大数据应用的分布式缓存系统,在读写流程、I/O事件驱动并发模型及元数据模型等方面进行了合理设计与优化,并使用fio工具测试了顺序写、随机写、顺序读及随机读场景下的吞吐率与IOPS等性能指标,验证了该分布式缓存系统的高性能优势和应对高并发场景的扩展能力。 相似文献
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多媒体存储系统必须同时支持连续媒体和非连续媒体的访问.由于连续媒体的实时要求,系统必须为访问连续媒体保留大量的磁盘带宽,并且持续很长的时间,这使其他类型文件的访问性能严重下降.本文根据连续媒体的访问特性,提出了一个分布式多媒体存储系统的协同缓存策略GLNU,充分利用系统中其他结点上可用的内存资源,提高缓存的利用率,以减少连续媒体的磁盘I/O,从而提高其他媒体的访问性能.仿真试验表明GLNU在各种不同的参数下,均优于现有的缓存策略,是一种适合分布式多媒体存储系统的缓存策略. 相似文献
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文件库大小对无线边缘缓存的性能具有重要的影响。本文基于Zipf文件流行度模型,分析了文件库大小与用户请求数、流行度参数等因素的渐近关系。研究结果表明,当用户请求数较少时,文件库大小随请求数线性增长,而当请求数较多时,文件库大小随请求数呈负指数增长,这一结论适用于不同的流行度参数。仿真结果验证了所分析结果的准确性,并基于校园网中采集的典型视频网站请求记录验证了分析结果的有效性。在实际系统中,无线边缘节点覆盖范围内的用户请求数通常远小于视频网站的文件总数,因此用户请求的文件库大小随请求数线性增长,而非文献中猜测的亚线性增长,这对提升无线边缘缓存性能带来严峻挑战。 相似文献
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一种分布式磁盘缓存的设计与实现 总被引:1,自引:0,他引:1
为了提高系统10性能,针对松散耦合环境下,高带宽、低延迟的传输特点,提出了一种通过扩展存储器层次结构来提高系统10性能的分布式系统——分布式磁盘缓存系统DRACO。通过利用分布式环境中空闲内存节点的剩余内存,扩充系统整体缓存容量,减小访问磁盘数据的频度,最终达到提高系统整体性能的目的。 相似文献
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三种无线分布式网络的比较 总被引:2,自引:0,他引:2
无线分布式网络近年来受到了越来越广泛的关注,adhoc网络、无线传感器网络和无线Mesh网络是目前无线分布式网络中最具代表性的3种类型。本文着重对这3种无线分布式网络的基本概念、技术特点和应用场合进行了分析研究和比较。 相似文献
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Fei Sun Bo Liu Fen Hou Haibo Zhou Jiacheng Chen Yun Rui Lin Gui 《Wireless Communications and Mobile Computing》2016,16(12):1612-1624
Distributed caching‐empowered wireless networks can greatly improve the efficiency of data storage and transmission and thereby the users' quality of experience (QoE). However, how this technology can alleviate the network access pressure while ensuring the consistency of content delivery is still an open question, especially in the case where the users are in fast motion. Therefore, in this paper, we investigate the caching issue emerging from a forthcoming scenario where vehicular video streaming is performed under cellular networks. Specifically, a QoE centric distributed caching approach is proposed to fulfill as many users' requests as possible, considering the limited caching space of base stations and basic user experience guarantee. Firstly, a QoE evaluation model is established using verified empirical data. Also, the mathematic relationship between the streaming bit rate and actual storage space is developed. Then, the distributed caching management for vehicular video streaming is formulated as a constrained optimization problem and solved with the generalized–reduced gradient method. Simulation results indicate that our approach can improve the users' satisfaction ratio by up to 40%. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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大规模MIMO OFDMA下行系统能效资源分配算法 总被引:4,自引:0,他引:4
针对大规模多输入多输出(MIMO)正交频分多址(OFDMA)下行移动通信系统,提出了一种基于能效最优的资源分配算法。所提算法在采用迫零(ZF)预编码的情况下,以最大化系统能效的下界为准则,同时考虑每个用户的最低速率要求,通过调整带宽分配、功率分配和基站天线数分配来优化能效函数。首先根据优化条件提出了一种迭代算法确定每个用户的带宽分配,然后利用分数规划的性质并采用凸优化方法,通过联合调整基站端的发射天线数和用户的发射功率来优化能效函数。仿真结果表明,所提算法在较少迭代次数的同时能够取得较好的系统能效性能和吞吐量性能。 相似文献
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Bouchaib Assila Abdellatif Kobbane Jalel Ben-Othman 《International Journal of Communication Systems》2023,36(1):e4358
Over-The-Top broadcasts a huge number of medias that mobile network operators have to manage efficiently before to deliver it to their subscribers. We propose an economic pricing approach to address caching resource management issues in the 5G wireless networks and to overcome limitations in terms of throughput, latency, and reliability. Moreover, we consider this approach based on an oligopolistic multi-market deducted from Cournot, Stackelberg, and Bertrand models. For simulation purpose, we consider the routing protocol (Ad-hoc On-Demand Distance Vector [AODV]) commonly used for the wireless network. We use the NS-2 package, and we analyze results in terms of End-to-End delay representing latency, throughput, packet delivery ratio, and normalized network load. 相似文献
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A framework of data caching for improving decoding efficiency of opportunistic network coding 下载免费PDF全文
Throughput performance of wireless networks can be enhanced by applying network coding (NC) technique based on opportunistic listening. The packets sent or overheard by a network node should be locally cached for the purpose of possible future decoding. How to manage the cache to reduce the overhead incurred in performing NC and, meanwhile, exploit performance gain is an interesting issue that has not been deeply investigated. In this paper, we present a framework for packet caching policy in multihop wireless networks, aiming at improving decoding efficiency, and thus throughput gain of NC. We formulate the caching policy design as an optimization problem for maximizing decoding utility and derive a set of optimization rules. We propose a distributed network coding caching policy (NCP), which can be readily incorporated into various existing NC architectures to improve NC performance gain. We theoretically analyze the performance improvement of NCP over completely opportunistic NC (COPE). In addition, we use simulation experiments based on ns‐2 to evaluate the performance of NCP. Numerical results validate our analytical model and show that NCP can effectively improve the performance gain of NC compared with COPE. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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通信系统是体现智能配电网使用性能的重要因素.基于异构融合网络的通信系统能够更好地满足实际的通信需求.本文从智能配电网通信系统的特点入手,对面向智能配电的异构融合网络无线资源管理进行分析. 相似文献