分类：设计开发    下载：0    浏览：422    时间：2017-08-09

摘要：介绍了WiMAX 16d 网络的架构和规划要点,对WiMAX 16d 组网的经验进行了分析和说明, 并提出了面向未来网络建设的相关建议。 关键词：WiMAX IEEE 802.16 QoS 非视距

分类：设计开发    下载：0    浏览：397    时间：2017-08-09

邵长虎, 徐友云, 张　乐 (上海交通大学电子工程系, 上海200240) 摘　要: 卷积Turbo 码是很灵活的码字, 帧长和码率的变化范围很大, 这也是选它做为WiMax(World Interoperability for Microwave Access) 标准中的信道编码方案之一的主要原因, 它采用递归系统卷积码作为子码, 相对于经典Turbo 码, 它具有编码效率高, 相同复杂度译码器下纠错性能好以及译码时延小等优点。详细介绍了卷积Turbo 码的编译码器结构, 提出译码方案, 并且给出仿真性能曲线。 关键词: WiMax ; 卷积Turbo 码; 交织器; 环形网格图

分类：设计开发    下载：0    浏览：392    时间：2017-08-09

Abstract — In this paper, the performance of WiMAX network with DL SIMO, DL MIMO and UL SIMO is analyzed via system simulations. Two data traffic models are considered, namely web browsing (HTTP) and full buffer sessions, operating in multi path fading channels such as the ITU Pedestrian-B and Vehicular-A channels. The control channel coverage and reliability of WiMAX using realistic overhead is also analyzed in this paper.

分类：设计开发    下载：0    浏览：406    时间：2017-08-09

摘要：以WiMAX 的网络架构与3GWCDMA PS 的系统架构作对比, 对3GWCDMA PS 域的发展方向进行了讨论。 关键词：WCDMA PS WiMAX NWG SAE

分类：其它    下载：0    浏览：407    时间：2017-08-09

 Intel关于wimax技术的介绍

分类：设计开发    下载：0    浏览：292    时间：2017-08-09

ABSTRACT IEEE 802.16e, known as Mobile WiMAX, has gained much attention recently for its capability to support high transmission rates in cellular environments and QoS for different applications. Beyond what the standard can define, in order to effectively support video streaming, VoIP, and data services, proprietary radio resource management, including multiconnection assignment, scheduling controls, and call admission controls, are essential. In this study we evaluate the downlink performance of a Mobile WiMAX cellular system with different radio resource management, especially the scheduler for QoS control and the implementation of multiconnection for streaming applications.

分类：设计开发    下载：0    浏览：407    时间：2017-08-09

Mobile WiMAX是对固定wimax的修订，增加了支持移动性的能力。完完全全成为一种移动通信技术。在当前几种3G技术体制纠缠不清，3G市场发展不明朗的今天，Mobile wimax能够得到如此关注是与其本身的技术优势和市场拓展策略分不开的。

分类：设计开发    下载：0    浏览：370    时间：2017-08-09

ABSTRACT The IEEE 802.16 standard (commonly known as WiMax) has emerged as one of the strongest contenders for broadband wireless access technology. At the same time, with the steady growth of real-time services such as voice over IP and video on demand, supporting delay sensitive streaming data overWiMax is becoming crucial. In this article we use commonly used techniques such as forward error correction (FEC) and automatic repeat request (ARQ) tosupport streaming services over WiMax without violating what has already been standardized. In particular, we look at the flexible features provided by media access control (MAC) layer of WiMax and exploit them for providing better streaming performance. We use the channel state information to dynamically construct the MAC packet data units. The sizes of these units are thusly determined such that the packet dropping probability is minimized without compromising the goodput. The simulation results presented show the performance enhancements of the proposed ARQ-enabled adaptive algorithm for streaming data.

分类：设计开发    下载：0    浏览：452    时间：2017-08-09

Abstract—The voice-over-Internet protocol (VoIP) service is expected to be widely supported in wireless mobile networks, though its feasibility and capacity have not been studied in relation to the emerging IEEE 802.16e orthogonal frequency division multiple access (OFDMA) system. Using analytical and simulation models that we developed, we present the downlink performance of VoIP services over an IEEE 802.16e OFDMA system. Index Terms—IEEE 802.16e, voice-over-Internet protocol (VoIP), broadband wireless access, queueing analysis

分类：其它    下载：2    浏览：615    时间：2017-08-09

目 录 1. 无线宽带接入技术...........................................................................................................4 1.1 技术标准........................................................................................................................4 1.2 各种无线接入技术比较................................................................................................8 1.3WIMAX 的关键技术....................................................................................................11 1.4 宽带无线接入的解决方案..........................................................................................12 2. WIMAX 的产业链.........................................................................................................16 2.1WIMAX 发展为产业链上的企业提供的机会............................................................16 2.2 一些大的设备商对WIMAX 的态度及举措..............................................................17 2.3 制造商的态度..............................................................................................................19 2.4 运营商的态度..............................................................................................................19 2.5 我国试验网建设..........................................................................................................19 2.6 我国政府的态度..........................................................................................................20 2.7WIMAX 的吸引力........................................................................................................20 3. WIMAX 与3G 的比较.................................................................................................21 4. WIMAX 应用面临的问题.............................................................................................23 4.1 频谱资源问题..............................................................................................................23 4.2 覆盖问题......................................................................................................................26 4.3WIMAX 组网问题........................................................................................................27 4.4 运营风险......................................................................................................................28 4.5 业务模式问题..............................................................................................................28 4.6 来自新技术的挑战......................................................................................................28 5. WIMAX 的应用定位及适用的范围.............................................................................29 5.1 光纤和PDH/SDH 微波的替代和补充[10][1]................................................................30 5.2 电信级点对点宽带无线[10]..........................................................................................32 5.3 其他手段难以实施的场景[10][1]...................................................................................34 6. WIMAX 可能的发展趋势.............................................................................................39 6.1 宽带无线接入技术的发展趋势..................................................................................39 6.2WIMAX 与3G 之间可能出现竞争与融合的趋势.....................................................40 6.3WIMAX 可能的商业模式............................................................................................41 7. 建议................................................................................................................................42 7.1WIMAX 市场尚未成熟................................................................................................42 7.2WIMAX 将在中国的城市地区得到广泛应用.............................................................42 7.3 我们可利用已有的频谱资源做WIMAX 的运营商..................................................43 7.5 不要忽视短距离低速率无线接入系统......................................................................43 7.6 只有积极参与，才能有更多收获..............................................................................44 7.7 未来的研究方向..........................................................................................................44 8. 参考文献.........................................................................................................................47

分类：设计开发    下载：0    浏览：318    时间：2017-08-08

摘要： 无线传感器网络是当前信息技术的前沿之一,在生态环境监测、基础设施安全、先进制造、物流管理、医疗健康、工业传感、智能交通控制、智能能源及军事等领域具有十分广阔的应用前景.无线传感器网络独特的要求和制约因素决定了不能仅只依靠现有的网络机制和技术,而必须重新设计适合无线传感器网络特点和要求的自组织自适应的网络.分析了传感器网络自组织、自适应的特点与需求,并在此基础上就其中的若干关键性科学问题进行了探讨.

分类：设计开发    下载：0    浏览：416    时间：2017-08-08

摘要        在移动Ad hoc网络环境下运用移动代理系统，极易受到DoS攻击，以往的解决方案都有一定的局限性，就此问题描述了一种新的安全解决方案，研究了该方案中所使用的技术，并提出了一些改进的设想，对相关的问题进行了讨论。 关键词        Ad hoc网；移动代理；安全漏洞；DoS攻击；模糊控制