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WiMAX端到端接入策略研究 总被引:1,自引:1,他引:0
作为现有网络及未来3G网络的有益补充,WiMAX在远距离传输、高速宽带接入及多媒体通信等方面具有非常突出的优势。WiMAX端到端网络的最终目标是确保业务质量并将其安全地发布到终端用户,文中紧紧围绕WiMAX发展前沿的热点问题,根据未来的发展趋势,主要分析了几种WiMAX终端设备能力以及可能的端到端接入情况,并对这些端到端组网方案进行了研究。 相似文献
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文中利用信道接入技术对通信端到端的传输时延进行计算,首先将时延分为传输设备传输时延、数据帧长度时延、线路时延,然后计算通信端到端的传输时延,以获得整个通信信号时序序列的计算方法。利用信道接入技术,采用计算模型,计算时延序列中单组信号的出现概率,在此基础上计算出通信端到端的传输时延。最后开展仿真实验,实验结果表明信道接入能够减少计算误差。 相似文献
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IPTV是电信运营商从传统电信网络运营商向综合信息服务提供商转型的一项战略性业务,它充分体现了"Triple-Play"的优势,是三网融合的典型代表.由于IP网络是一个尽力而为(BE)的普遍服务型网络,而IPTV是一个对实时性,音视频质量要求较高的业务,因此,深入分析影响IPTV业务质量的因素并有针对性地加以解决,将有效提高IPTV业务质量,提高IPTV业务的社会认同感,有利于IPTV业务广泛开展.本文从IPTV平台、承载网络、终端等层面分析,提出了IPTV业务端到端的质量保障方案. 相似文献
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对路由变化的分析和预测,是网络测量的一个重要方面。通过对端到端路由测量结果的分析,来验证Internet路由的若干特性。路由的变化与路由选择策略是密不可分的,同时,路由的变化也会造成网络性能的变化,从而影响其他网络测量的度量。通过对RTT和返回分组TTL值的变化规律的分析,可以帮助定位网络瓶颈,预测路由变化,因此可以作为研究网络路由的一个重要手段。 相似文献
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近年来深度伪造(Deepfake)技术的迅猛发展使合成语音的自然度和拟人度有了显著提升,对合成语音检测研究提出了更大挑战。本文将五种轻量级注意力模块中的机制改进为适用于语音序列的通道注意力机制和一维空间注意力机制,然后将模块分别嵌入到Inc-TSSDNet网络中,提出基于注意力机制的端到端合成语音检测系统。结果表明,改进系统能够重点关注某些对于检测真伪更关键的通道或区域来提高检测性能,相比于基线模型,引入注意力机制的十种模型在增加的参数量较少的情况下,ASVspoof2019测试集的等错误率(Equal Error Rate,EER)和最小串联检测代价函数(Minimum Tandem Detection Cost Function,min t-DCF)都有所降低,其中在池化层之前嵌入CBAM(Convolutional Block Attention Module)的模型测试集EER最低且具有较强的泛化性,在池化层之前嵌入ECA(Efficient Channel Attention)模块的模型测试集min t-DCF最低且统计性能较基线模型有显著提升。 相似文献
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根据信息产业部的官方数据 ,中国大陆地区的移动用户已达1.2亿 ,并以年均80 %的速度持续增长 ,这种蓬勃发展的市场趋势将很快把移动通信市场的竞争从网络规模演变为网络服务质量的竞争 ,并且随着市场的进一步开放必将加剧网络服务质量(QoS)对新、老运营商的压力。遗憾的是当前的2G和2.5G技术在QoS方面都没有明确的措施 ,只能靠对网络进行繁琐的局部优化 ,这已经极大地影响了移动用户的满意程度 ,进而阻碍了移动增值新业务的推出。相对于以往的移动技术体制 ,第三代移动通信技术UMTS最大的好处之一是赋予了运营商管理… 相似文献
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Broadband wireless access solutions based on OFDM access in IEEE802.16 总被引:23,自引:0,他引:23
Broadband wireless access is the most challenging segment of the wireless revolution since it has to demonstrate a viable alternative to the cable modem and DSL technologies that are strongly entrenched in the last mile access environment. The Analysis, Research, and Consultancy (ARC) Group forecasts that the fixed wireless deployments in both homes and businesses will reach almost 28 million by 2005, with North America and Western Europe accounting for 24 percent and 27 percent of these, respectively. Whether the promise of BWA will materialize depends on its appeal to telecom operators from the perspective of deployment economics, where the critical factor is the ease of installation of broadband wireless subscriber units. This ultimately leads to nonprofessional installation of integrated all-indoor BWSUs. Consequently the physical layer (PHY) has to mitigate the very tough impairments that characterize these non-line-of-sight environments. In this context we overview the work of the one of the IEEE 802.16 standard subcommittee projects that deals with a BWA solution based on OFDM access (OFDMA) aiming at the most challenging NLOS scenarios 相似文献
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We address the problem of detecting a rogue base station (Bs) in WiMax/802.16 wireless access networks. A rogueBs is a malicious station that impersonates a legitimate access point (Ap). The rogueBs attack represents a major denial-of-service threat against wireless networks. Our approach is based on the observation that inconsistencies in the signal strength reports received by the mobile stations (Mss) can be seen if a rogueBs is present in a network. These reports can be assessed by the legitimate base stations, for instance, when a mobile station undertakes a handover towards anotherBs. Novel algorithms for detecting violations of received signal strength reports consistency are described in this paper. These algorithms can be used by an intrusion detection system localized on the legitimateBss or on a global network management system operating theBss. 相似文献
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Cecília A.C. César Solon V. Carvalho 《International Journal of Communication Systems》2015,28(5):910-927
The IEEE 802.16 standard for wireless broadband networks includes the mesh mode in its specifications, where network nodes interact to deliver packets from a client to a remote destination through intermediate nodes. This paper presents a study of the capacity of IEEE 802.16 wireless networks in mesh mode by using M/G/1/L queuing model that represents each network node by incorporating the features of the standard in order to calculate the average delay and throughput in the node. An iterative method integrates the calculation results at each node, obtaining the end‐to‐end delay from any node of the mesh to the Base Station. Because of multiple hops, a node far from the Base Station may have its flows damaged. To minimize this problem, we propose a criterion for a fair distribution of resources. We show the numerical results of the model which indicate a good fit when compared with simulation results. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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IEEE802.16a是固定宽带无线接入系统最新国际标准,基于该标准的宽带无线接入系统在无线传输方面具有调制方式动态选择的特点,可支持多业务;介绍的宽带无线接入系统具备IEEE802.16a建议的物理层、MAC子层、业务汇聚子层、及加密子层等实体,同时描述了一个实际的宽带无线接入系统必须具备的业务接口处理及系统管理等实体,并给出了各实体间的关系。 相似文献
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for minimizing the total system cost. 相似文献
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在IEEE802.16e标准中,保证QoS的调度算法一直是人们研究的热点,它涉及到从单一业务到多级别业务的调度服务.对多级别业务调度的支持是保证系统性能的重要技术之一.本文针对多级别业务常用的分层调度和联合调度策略,从系统吞吐量、QoS性能和公平性等方面对之进行的仿真分析和性能比较.仿真结果表明联合调度策略综合性能较好. 相似文献
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未来移动通信系统,诸如IEEE802.16旨在能够传送多种具有不同QoS要求的多媒体业务.为了保证业务的QoS,需合理设计调度器的结构和相应的调度算法.针对IEEE 802.16宽带无线接入系统中的双层分级带宽分配体系结构,结合总调度器分配算法优点,采用了更适用于分类调度器且不同于 相似文献