3G室内覆盖组网中切换的设计

切换技术是移动通信关键技术之一,它直接影响到3G系统的容量和质量,平滑切换对移动终端在系统范围内实现连续的无中断通信是必不可少的。文章在基于移动通信切换技术分析的基础上,重点讨论了3G室内覆盖系统的组网方式和切换设计的具体方法,给出了分区和切换区域设计的细节,特别是多分区异频、同频结合的室内覆盖方案。这些讨论可为3G室内覆盖系统组网的实际工程建设提供一定的参考和帮助。     

一种基于速度感知的垂直切换算法

 未来的4G网络不是由单一的接入方式构成,而是采用不同的无线接入技术的多种网络的融合.不同网络接入技术间的切换称为垂直切换.本文提出了一种基于速度感知的垂直切换算法,不需确切的节点坐标和速度信息,利用接收信号强度的历史测量数据来表征节点运动速度的影响,提高对切换触发时机的准确判断.该算法可以自动调整以适应不同的节点运动速度,有效提高垂直切换的效率.仿真试验表明该算法能有效提高垂直切换的性能.     

3G室内覆盖工程设计中分区及切换技术的应用

以WCDMA为例讨论了3G室内覆盖系统的组网方式、分区和切换设计的具体方法,重点给出了室内覆盖系统分区策略、同频异频的选择和切换区的设置方案,并给出了工程设计的实例。     

3G室内覆盖解决方案

文章从信源的选择、频率的配置、室内天线的功率及有效覆盖半径、以及室内覆盖边缘场强等角度对3G室内覆盖进行了分析,总结了目前国内进行3G室内覆盖工程的可行方案.     

参数调整在室内覆盖话务提升中的应用

随着城市化建设进程的加快,各地市高层楼宇逐步增多,在高层楼宇内,由于网络干扰,信号漂移,导致室内分布系统话务吸收不足,高端客户投诉严重,本公司通过组织对室内覆盖系统进行精细参数调整,显著提升了室内覆盖话务量,并有效降低了室内客户投诉。     

双频网中的切换

切换是ＧＳＭ双频网的关键技术之一。对双频网中的复杂切换问题进行了详尽地分析，并提出在双频网环境下如何对切换进行正确地使用和控制。     

浅议3G中的各种切换技术

在第三代移动通信系统中．软切换已被作为种关键的技术广泛应用。本文详细论述了WCDMA、CDMA2000系统中的软切换和TD-SCDMA系纺中的切换策略及其执行过程，尤其是TD-SCDMA中的接力切换．并对他们的切换性能做了简单的比较。     

WCDMA室内覆盖商场临近马路场景切换设置

不同场景的室分系统切换设置有很大的不同,选取有代表性的室分站点,对室分典型场景即商场临近马路场景切换的特点进行探讨,并由此得出该特定场景室内覆盖切换的规划与优化原则。     

WCDMA室内覆盖切换性能规划优化研究

文章选取有代表性的室分站点,对室分典型场景、常见切换区域、切换特点进行探讨,并由此总结出室内覆盖切换的规划与优化原则。     

小区室内覆盖3G接入工程探讨

为了提升服务质量和降低用户投诉，国内的移动通信运营商都加大了对居民小区室内覆盖建设的力度。当以高速数据通信见长的第三代移动通信（3G）即将在国内登场时，小区室内覆盖建设必将面临不少难题。文章结合实际案例，对小区覆盖3G接入过程中需要注意的问题进行剖析，共同探讨解决思路。     

移动切换资源预留技术研究

论文介绍了移动通信中的QoS、资源预留协议及为保证各业务QoS的资源预留切换方案。在移动切换中对基于QoS保证的资源预留方案的研究现状进行了综述,并在资源预留方法方面提出了一种设想,最后指出了今后资源预留技术研究的趋势。     

Handoff Performance Improvement with Latency Reduction in Next Generation Wireless Networks

The next generation (NG) wireless networks are expected to provide mobile users with the real-time multimedia services. High sensitivity to time constraints like delay and jitter is one of the important characteristics of the multimedia traffic. In order to maintain a certain quality of service (QoS) level, the handoff latency should be minimized. Furthermore, if the new cell is not ready at the actual handoff time, the handoff call may be even forced terminated. Hence, the handoff preparation latency directly affects the performance of the cellular networks in terms of QoS support and the handoff blocking probability. In this paper, we present the expected visitor list (EVL) method to achieve reduced handoff blocking probability and maintain a certain QoS level in the network by minimizing handoff preparation latency. The handoff signaling decomposition is introduced to make the neighbor cells aware of the resource demands and QoS requirements of the mobile terminal before the actual handoff time. The obtained information about the prospective active mobile terminal is stored in an EVL entry at the neighbor cells. The call admission control (CAC) with QoS-provisioning is run against each EVL entry. According to the CAC result, the network preparation algorithms are executed and the results are stored in the entry. No resource reservation or allocation is performed in advance, and the varying network conditions are reflected to validity and admission status of the entries. The results of handoff preparation algorithms stored in the EVL entry are activated at the actual handoff time and hence the handoff latency is minimized. Performance evaluation through mathematical analysis and extensive simulation experiments show that the EVL method reduces handoff latency and hence handoff call blocking probability significantly without introducing high overhead.Özgür B. Akan received the B.S. and M.S. degrees in electrical and electronics engineering from Bilkent University and Middle East Technical University, Ankara, Turkey, in 1999 and 2001, respectively. He received the Ph.D. degree in electrical and computer engineering from the Broadband and Wireless Networking Laboratory, School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, in 2004. He is currently an Assistant Professor with the Department of Electrical and Electronics Engineering, Middle East Technical University. His current research interests include sensor networks, next-generation wireless networks, and deep space communication networks.Buyurman Baykal received his B.Sc. (High Hons.) degree in Electrical and Electronics Engineering from Middle East Technical University in 1990; M.Sc. (Distinction) and Ph.D. degrees in 1992 and 1995 from Imperial College of Science, Technology and Medicine. Dr. Baykal has research and teaching interests in speech processing, signal processing for telecommunications, and communication networks. He has extensive experience both in the theory and applications of adaptive signal processing techniques to communication applications such as acoustic echo cancellation, noise reduction, channel equalization and digital receiver design through self-conducted research and industry-funded research projects. He conducts research and implementation work on low bit rate speech coding and content based indexing of audio signals. He is also involved in communication network research with particular interest in ATM/IP design aspects, wireless networks and network management issues. Dr. Baykal is an Associate Editor of Computer Networks (Elsevier Science), Sensor Letters (American Scientific Publishing), a past Associate Editor of the IEEE Transactions on Circuits and Systems Part II—Analog and Digital Signal Processing (TCAS-II). He authored and co-authored over 50 technical papers.     

GSM移动通信网络掉话解析

本文将全面分析GSM移动通信系统中导致各类掉话的原因。在移动通信中,掉话可分为两种形式：一类是在SDCCH信道上的掉话,一类是在TCH信道上的掉话。掉话率作为反映网络性能的一项重要指标,一直是网络优化工作关注的重点。     

Integrating Distributed Channel Allocation and Adaptive Handoff Management for QoS-Sensitive Cellular Networks

Next generation high-speed cellular networks are expected to support multimedia applications, which require QoS provisions. Since frequency spectrum is the most expensive resource in wireless networks, it is a challenge to support QoS using limited frequency spectrum. In the literature, two orthogonal approaches are used to address the bandwidth utilization issue and the QoS provision issue; that is, channel allocation schemes have been proposed to improve bandwidth efficiency, whereas handoff management schemes, based on bandwidth reservation, have been proposed to guarantee a low connection dropping rate. However, little effort has been taken to address both issues together. In this paper, we integrate distributed channel allocation and adaptive handoff management to provide QoS guarantees and efficiently utilize the bandwidth. First, we present a complete distributed distributed channel allocation algorithm and propose techniques to reduce its message complexity and intra-handoff overhead. Second, we integrate the proposed distributed channel allocation algorithm with an adaptive handoff management scheme to provide QoS guarantees and efficiently utilize the bandwidth. Detailed simulation experiments are carried out to evaluate the proposed methodology. Compared to previous schemes, our scheme can significantly reduce the message complexity and intra-handoff overhead. Moreover, the proposed scheme can improve the bandwidth utilization while providing QoS guarantees.     

移动通信系统中的越区切换技术研究

针对切换策略和算法是决定3G网络性能好坏的关键因素之一,文章简单介绍了越区切换的原因,对越区切换的策略进行相关的论述,最后主要介绍了几种典型的越区切换算法,着重对资源预留和呼叫请求排队联合切换算法做了详细的分析.     

Performance Analysis of Channel Assignment with Prioritized Handoff Procedures in GSM

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下一代移动通信网络中的切换管理研究

本文概述了下一代移动通信网络中的切换管理研究框架结构,对切换管理研究涉及的领域加以介绍,并为下一代移动通信网络的切换管理系统性研究指引了方向.     

一种基于模糊逻辑的切换算法

针对蜂窝移动系统的越区切换,提出了一种基于模糊逻辑的切换判决算法.通过仿真与只以信号强度为指标的传统切换算法进行了性能比较,结果表明:采用多指标判决的模糊逻辑切换算法能够有效降低系统的掉话率和切换数量,提高服务等级.     

无线异构网络的垂直切换

传统意义上的水平切换算法已经在同构网络中得到很好的研究和应用,而随着多种无线异构网络的出现,下一代网络必须支持垂直切换技术以保证用户从一种类型的网络切换到另一种类型的网络时仍然保持连接。由于切换算法所需考虑因素的多样性和算法本身的复杂性,有必要对现有文献中的网络切换类型、切换因素、切换算法进行了归纳总结,并对垂直切换算法进行比较,指出未来切换算法的研究方向。     

基于双窗口测量的蜂窝移动通信系统越区切换算法性能分析

本文提出了一种新的蜂窝移动通信系统越区切换测量算法,该算法采用了两个长度不同的测量窗口,有利于在切换时延和切换平均次数这对矛盾之间取得更为有效的平衡,特别适用于需要对多个基站进行切换测量的情况.同时本文给出了基于矩形窗口的双窗口切换测量算法数学分析模型,及数值分析结果.