3G论文移动通信系统中位置管理技术研究与分析.doc

3G论文：移动通信系统中位置管理技术研究与分析【中文摘要】移动通信网络的特点在于用户的移动性,为了保证网络良好的移动性管理性能,一个好的位置管理(Location Management, LM)是不可或缺的。好的位置管理策略不但可以节约网略资源,还可以实现快速、稳定的无线连接,并能保障网络的有效运行随着3G(WCDMA、CDMA 20001xEV-DO、TD-SCDMA)、3.5G(HSDPA)、3.75G (HSUPA)以及4G无线通信网络系统在世界各地的相继开通,越来越多的用户数量可能在很大的区域范围内随机移动并要求能随时进行通信,而过于频繁的位置更新、查询和过于拥挤的寻呼等信息传递会产生很大的信令负荷,以致增大网络系统的处理时间和降低网络系统的通信容量,因此,怎样配置位置寄存器(集中式或是分布式)、怎样划分用户的位置区域(Location Area, LA),才能保证在呼叫到达时可以快速而准确地找到被叫用户,而同时又消耗比较少的有线和无线资源是十分重要的。2G通信系统位置管理采用两层数据库结构,使用固定的LA策略来进行位置管理,即对每个用户,LA的大小是固定的,它是根据总体的移动和呼叫统计来确定,对每个用户来说不是最好的,且不能适应用户移动性和呼叫特性的不断变化。2G系统网络构架以及所用的位置管理技术已无法满足下一代移动通信网络中用户越来越高的终端移动性和个人移动性。本论文以分析适合3G系统、并能提高网络性能的位置管理方案为主要研究目标,围绕与移动性相关的问题、并针对网络侧的存储用户位置信息的数据库和接入侧的位置更新及寻呼策略和算法进行了详细的分析研究,主要工作体现以下两方面：1.针对固定位置区位置更新策略及覆盖轮询的缺点,分析了一种动态位置更新方法及最短距离优先寻呼策略,并对该方法进行建模,包括网络系统假设,用户移动模型和寻呼模型建模,利用该模型推导出位置管理总代价理论表达式,分析了各种参数对位置管理性能的影响。并得出位置管理总开销是运动门限的(向下)凸函数、随呼叫移动比值的增大而明显降低、没有寻呼延迟限制的时候总开销会呈降低趋势,且对蜂窝逗留时间驻留时间方差不敏感。2.针对2G网络中位置管理数据库构架和位置管理方案的缺点,给出-种适用于3G系统的三层网络数据库结构的位置管理方案。介绍了数据库系统构架、位置更新流程、以及建立理论分析模型后,按照设置系统参数,进行数值分析,证明了3G中改进的位置更新方案有效改善了位置管理总代价提升了位置管理性能。【英文摘要】Mobile communication network is characterized by the user mobility, so, an location management strategy is indispensable to ensure the mobility management performance of the network.A good location management strategy can save network resources, provide fast and stably wireless connection, and guarantee the effective operation of the network.With the 3G (WCDMA, CDMA20001xEV-DO,andTD-CDMA),3.5G (HSDPA),3.75G (HSUPA), and 4G communication networks have appeared around the world, a large number of users will move randomly within the area and be abled to communicate at any time. But frequent location update, inquiry, crowded paging and other message transmission will have a significant signaling load, and it will increase processing time of network systems and reduce the communication capacity in network systems. Therefore, how to configure the location register (centralized or distributed) and how to divide the users location area is very important to ensure that the called user can be found quickly and accurately when the call arrives, and less wired and wireless resources are consumed at the same time.A two-tier location management database structure and a fixed LA strategy is used for location management in 2G communication system.The fixed LA strategy is that LA size is fixed for each user, and it is determined based on the overall movement and call statistics. Its not the best size for each user, and it cant adapt to the user mobility and call characteristics changing constantly.2G network architecture and location management technologies have been unable to meet the high terminal mobility and personal mobility of users in next generation mobile communication network.The main research objective of this paper is to analyze a location management solution for 3G systems which can improve network performance. The database to store user location information on the network side and the location update and paging strategies and algorithms on access side are analysised in this paper focus on the issues related to mobility. The m-ajor work of this paper is presented as follows:1. A dynamic location update method and the shortest distance priority paging strategy against the shortcomings of fixed LA location update strategy and blanket paging are analyzed, and then, the model including network hypothesis, user mobility and paging modeling are made, the theoretical expression of the total cost of location management is derived using this model. At last, the influence of various parameters on the performance of location management are given, through the analysis it is found that the total cost of location management is a convex function (down) of the movement threshold, and it willl significantly reduced with the increase of call-to-mobility-ratio. The total cost of location management will be decrease without paging delay, and it is not sensitive to the variance of cell dwell time.2. A location management scheme for 3G which have a three-tier database structure against the shortcomings of the database architecture and location management scheme in 2G is proposed. Then, the database system architecture, the location update process and the theoretical model of this scheme are introduced.After that, numerical analysis on it is done, and the conclusion that this scheme for 3G reduce the total location management cost significantly, and the performance of location management is improved effectively are given.【关键词】3G 位置管理 位置更新 寻呼 移动阈值 小区逗留时间 呼叫到达率【英文关键词】3G location management location update paging movement threshold cell dwell time call arrival rate【目录】移动通信系统中位置管理技术研究与分析摘要6-8Abstract8-9第1章 绪论12-231.1 课题的研究背景12-141.2 位置管理研究内容14-151.3 现有系统中位置管理方法15-201.3.1 2G通信系统中普遍使用的位置管理方法15-171.3.2 2.5G、2.75G通信系统中的位置管理技术171.3.3 3G位置管理技术17-201.4 目前位置管理策略的不足20-211.5 论文的主要研究内容以及结构安排21-23第2章 位置管理概述23-392.1 位置管理方案的研究现状23-262.1.1 集中式位置管理23-252.1.2 分布式位置管理25-262.2 位置更新和寻呼26-332.2.1 位置更新27-312.2.2 终端寻呼31-332.3 位置管理仿真建模33-372.3.1 仿真模型描述332.3.2 网络拓扑模型33-352.3.3 移动模型35-372.3.4 驻留时间模型372.3.5 呼叫模型372.4 本章小结37-39第3章 基于运动量的位置管理方案建模及性能分析39-563.1 系统描述及方案介绍40-433.1.1 系统假设40-413.1.2 更新策略41-423.1.3 寻呼策略42-433.2 方案建模43-473.2.1 用户移动模型43-463.2.2 位置更新及寻呼开销46-473.3 数值结果及性能分析47-553.3.1 移动阈值对位置管理性能的影响47-503.3.2 呼叫移动比、寻呼时延及对位置管理性能的影响50-513.3.3 逗留时间方差对位置管理性能的影响51-553.4 本章小结55-56第4章 一种适用于3G系统的位置管理方案建模及性能分析56-704.1 本章系统结构描述及方案介绍57-584.1.1 数据库系统构架574.1.2 位置更新和寻呼策略57-584.2 3G中三层数据库动态位