3G网络中无线链路预算的优化组合分析

研究了3G网络中的链路预算和网络投资的关系，并引用经济管理学中的价值工程理论．从技术和经济两方面对链路预算的规划和优化进行了分析研究，给出了3G网络无线链路预算的优化组合方法和具体应用建议，以节省3G网络的投资。     

3G UMTS网络的无线链路增强技术--HSDPA/HSUPA

HSDPA和HSUPA是3GPP协议规范中定义的UMTS网络无线链路增强技术，分别在Release 5和Release 6中引入。文章在介绍HSDPA和HSUPA采用的关键技术的基础上，对两种无线链路增强技术进行了简要的比较分析。     

3G无线接入网的两种传输技术

根据3G技术无线接入网的技术要求,对无线接入网的两种传输技术--多业务传输平台(MSTP)和异步传输模式(ATM)进行了比较,同时考虑到实际组网需适应3G网络的业务特点和传输网的未来发展,结合国内外ATM和MSTP实际应用状况,可以认为MSTP作为3G无线接入网的过渡技术,其成本较低,是目前传送网的最佳解决方案.     

基于3G网络的新型无线监控系统

以3G网络为平台,设计开发了一种新型的无线监控系统.本系统由两大部分组成:终端影像监控设备和后台计算机监控中心.两部分之间通过3G网络进行实时数据传输.本文主要研究了视频数据编码技术和无线信号射频收发技术,设计了一种新型的适用于本系统的编码原则和射频收发技术方案.     

提高乡镇3G网络无线资源利用率的分析及研究

随着3G建设的发展,郊区乡镇普遍存在3G资源利用率低、2G/3G话务不均衡、3G用户回落2G网络比例较高等情况.对乡镇3G基站运行情况进行了分析,并提出了优化整改方案和思路,通过实际案例表明该方案可以有效提高乡镇3G基站的资源利用率、平衡2G/3G话务负荷,对于后期的3G以及4G建站模式具有一定的参考价值.     

缩短2G/3G重选时延的一种方法

随着TD-SCDMA网络建设规模的不断扩大,2G与3G网络间的重选非常频繁,TD-SCDMA与GSM系统间重选时延较长是目前影响网络接通率的一个重要因素.如何缩短2G/3G重选时延、改善呼叫不可达问题,提升用户感受,是2G/3G网络融合的又一重要课题.TD/GSM双网准Fast Return技术提供了一种TD-SCDM...     

3G长期演进系统无线资源下行链路调度算法初探

文章主要阐述三种经典的OFDM系统中的资源调度算法比较,同时简略介绍现阶段流行的调度算法,并指出,能更好地协调多维度的资源调度、跨层调度、包调度与其他的无线资源管理方法紧密结合的调度方法都是今后的研究方向.研究方向.     

基于3G网络的远程无线监控系统设计

针对远程无线监控系统的应用需求和移动通信的发展,提出一种基于2G/2.5G/3G网络的远程无线监控系统,设计了系统的总体方案,介绍了系统的组成结构和工作原理,着重阐述了系统的硬件和软件设计。该系统拓展了移动通信网络的应用范围,提高了远程监控系统的灵活性和稳定性,具有广泛的应用前景。     

后3G移动通信无线接入网络的发展趋势

本文研究了移动通信网中各种无线接入系统标准和异种网络构架，分析了不同无线接入网的控制方式和拓扑结构，探讨了适合后3G移动通信系统发展的无线接入网构架。     

3G网络与2G网络的兼容性规划设计

随着国内3G运营牌照发放的日益临近,3G网络规划的工作显得越来越重要,尤其是如何利用现有2G网络资源向3G网络成功过渡的策略研究成为重中之重。文章首先介绍了3G网络与2G网络兼容性规划设计的流程与方法,并就普遍关注的WCDMA与GSM共同规划的实例展开讨论,分析了兼容性规划中的细节问题,最后简单讨论了兼容性规划设计的一些新问题和解决思路。     

3G无线网络仿真

本文介绍了在获得某个地区校正后的传播模型后,如何进行该地区3G无线网络仿真的方法、步骤及相关注意事项.文章结尾给出了某城市3G无线网络仿真结果,供大家参考.     

面向3G的无线网络优化体系

分析了3G对网络优化的新要求，并介绍了网络优化技术发展的一些动向，最后讨论了面向3G的融合的优化体系架构。     

RObust Header Compression (ROHC) Performance for Multimedia Transmission over 3G/4G Wireless Networks

RObust Header Compression (ROHC) has recently been proposed to reduce the large protocol header overhead when transmitting voice and other continuous media over IP based protocol stacks in wireless networks. In this paper we evaluate the real-time transmission of GSM encoded voice and H.26L encoded video with ROHC over a wireless link. For the voice transmission we examine the impact of ROHC on the consumed bandwidth, the voice quality, and the delay jitter in the voice signal. We find that for a wide range of error probabilities on the wireless link, ROHC roughly cuts the bandwidth required for the transmission of GSM encoded voice in half. In addition, ROHC improves the voice quality compared to transmissions without ROHC, especially for large bit error probabilities on the wireless link. The improvement reaches 0.26 on the 5-point Mean Opinion Score for a bit error probability of 10^–3. For the video transmission we examine the impact of ROHC on the consumed bandwidth. We find that the bandwidth savings with ROHC depend on the quantization scale used for the video encoding and the video content and ranges between 5–40% for typical scenarios.Frank H.P. Fitzek is an Associate Professor in the Department of Communication Technology, University of Aalborg, Denmark heading the Future Vision group. He received his diploma (Dipl.-Ing.) degree in electrical engineering from the University of Technology – Rheinisch-Westflische Technische Hochschule (RWTH) – Aachen, Germany, in 1997 and his Ph.D. (Dr.-Ing.) in Electrical Engineering from the Technical University Berlin, Germany in 2002. As a visiting student at the Arizona State University he conducted research in the field of video services over wireless networks. He co-founded the start-up company acticom GmbH in Berlin in 1999. In 2002 he was Adjunct Professor at the University of Ferrara, Italy giving lectures on wireless communications and conducting research on multi-hop networks. His current research interests are in the areas of 4G wireless communication, QoS support for multimedia services, access techniques, security for wireless communication, and the integration of multi hop networks in cellular systems. Dr. Fitzek serves on the Editorial Board of the IEEE Communications Surveys and Tutorials. He is the program chair for the International Conference on Advances in Computer Entertainment Technology (ACE2004) and serves in the program committee for VTC2003, VTC2004, ACE2004, and IEEE MWN2004.Stephan Rein studied Electrical Engineering at the Technical University of Aachen, Germany, and the Technical University of Berlin (TUB), Germany. He received the Dipl.-Ing. degree in electrical engineering from the TUB in 2003. From March 2003 to October 2003 he visited the multimedia networking group in the Department of Electrical Engineering at Arizona State University, Tempe. He is currently pursuing the Ph.D. degree at the Institute for Energy and Automation Technology, Technical University of Berlin. His current research interests include data compression and digital signal processing with emphasis on wavelet theory.Patrick Seeling received the Dipl.-Ing. degree in industrial engineering and management (specializing in electrical engineering) from the Technical University of Berlin (TUB), Germany, in 2002. Since 2003 he has been a Ph.D. student in the Department of Electrical Engineering at Arizona State University. His research interests are in the area of video communications in wired and wireless networks. He is a student member of the IEEE and the ACM.Martin Reisslein is an Assistant Professor in the Department of Electrical Engineering at Arizona State University, Tempe. He received the Dipl.-Ing. (FH) degree from the Fachhochschule Dieburg, Germany, in 1994, and the M.S.E. degree from the University of Pennsylvania, Philadelphia, in 1996. Both in electrical engineering. He received his Ph.D. in systems engineering from the University of Pennsylvania in 1998. During the academic year 1994–1995 he visited the University of Pennsylvania as a Fulbright scholar. From July 1998 through October 2000 he was a scientist with the German National Research Center for Information Technology (GMD FOKUS), Berlin. While in Berlin he was teaching courses on performance evaluation and computer networking at the Technical University Berlin. He is editor-in-chief of the IEEE Communications Surveys and Tutorials and has served on the Technical Program Committees of IEEE Infocom, IEEE Globecom, and the IEEE International Symposium on Computer and Communications. He has organized sessions at the IEEE Computer Communications Workshop (CCW). He maintains an extensive library of video traces for network performance evaluation, including frame size traces of MPEG-4 and H.263 encoded video, at . He is co-recipient of the Best Paper Award of the SPIE Photonics East 2000 – Terabit Optical Networking conference. His research interests are in the areas of Internet Quality of Service, video traffic characterization, wireless networking, and optical networking.     

TCP/IP Performance over 3G Wireless Links with Rate and Delay Variation

Wireless link losses result in poor TCP throughput since losses are perceived as congestion by TCP, resulting in source throttling. In order to mitigate this effect, 3G wireless link designers have augmented their system with extensive local retransmission mechanisms. In addition, in order to increase throughput, intelligent channel state based scheduling have also been introduced. While these mechanisms have reduced the impact of losses on TCP throughput and improved the channel utilization, these gains have come at the expense of increased delay and rate variability. In this paper, we comprehensively evaluate the impact of variable rate and variable delay on long-lived TCP performance. We propose a model to explain and predict TCPs throughput over a link with variable rate and/or delay. We also propose a network-based solution called Ack Regulator that mitigates the effect of variable rate and/or delay without significantly increasing the round trip time, while improving TCP performance by up to 100%.     

应用于ROHC的窗基LSB编解码修正算法实现机制

在移动：IPv6中，常常因为数据分组的头标太大而消耗过多的带宽，因而需要使用灵活可靠的鲁棒性头标压缩机制(ROHC)来对分组头标进行压缩。在ROHC中，使用LSB编码方案对分组中那些变化比较小的头标域进行编码。本文将在简要介绍ROHC原理的基础上，深入探讨应用于ROHC的窗基LSB编解码修正算法的实现机制。     

3G无线网络覆盖和容量的规划设计

随着我国3G系统建设的全面启动,3G网络规划设计已成为研究的热点之一。为了实现建设目标,在进行3G无线网络规划设计时,必须同时考虑覆盖、容量及不同服务质量的要求。文章对无线网络覆盖和容量的规划设计进行了论述,分析了覆盖和容量的关系,讨论了覆盖规划、容量规划等几个重要问题。特别对链路预算、传播模型、容量估算和极限容量等进行了阐述,给出了上行极限容量分析及上行链路容量规划的举例。     

无线网络中提高IP传输效率方法分析

随着无线通信技术的发展,业务种类和数据量急剧增加,使得有限的频带资源变得更加紧张,因此在无线IP网络里,对数据包进行压缩,可以有效提高链路的利用率。这里主要讨论对数据包头进行压缩来提高传输效率。通过分析目前无线网络中IP层传输效率提高的瓶颈,结合目前常用的包头压缩技术,分析了IETF提出的IPHC和ROHC这2种IP头部压缩的方法,并结合无线信道的特点提出适合短生命周期的报文进行头部压缩的机制。     

3G无线网络规划流程

本文概述了第三代移动通信网络一期建网无线规划的一般流程.并对规划流程中几个关键步骤进行了深入的探讨.     

基于3G传输的视频监控系统的后台设计

设计了一种基于3G网络传输的移动视频监控系统的后端管理服务平台(后台);结合视频监控系统总体设计框架,对后台的设计方案及RTP解封、AES解密、音视频解码、音视频配置及USB管理等各功能模块设计和实现方法作了详细介绍.经测试,该平台工作稳定,在视频监控领域应用良好.     

针对3G上网用户的无线网络加速系统

随着3G上网业务的不断发展,越来越多的用户使用3G网络移动上网,这样会导致无线资源紧张,影响用户的使用体验,同时也给移动网络带来了沉重的负担。针对这一问题开发了针对3G移动上网用户Web应用的无线网络加速系统,该系统使用缓存和数据压缩技术,可以通过单向透明或者双向透明2种无客户端的方式部署在移动数据网到互联网的出口位置,以便于产品的推广使用。对该系统进行的现网测试包括单用户测试和现网流量测试两个部分,测试结果表明,使用无线网络加速系统大幅度减少移动上网用户的Web页面打开时间,从而提高了用户体验;同时使用该系统后,对于移动用户的Web应用产生的流量,在网络出口一侧和无线接入网一侧,能实现16%以上的流量节省。