移动通信中的位置管理

蜂窝移动通信系统的位置管理策略的合理选择，可以明显减少系统中无线信道资源的消耗。本文介绍了位置管理的基本操作，回顾了现有2G系统使用的位置管理方案和2．5G系统中对位置管理策略的改进，重点对要求最高2Mbps数据传输率的3G系统所要采用的位置管理方式进行了综合分析，并提出一种位置管理策略的改进。     

军用PCS系统中移动基站的位置更新策略

本简要介绍了军用PCS系统关键技术之一的移动基站技术的概念，以第二代数字移动通信系统GSM为基础，对移动基站的位置更新的用户群的位置更新提出了新的更新策略，补充，完善了原的的位置更新的协议，使得新的协议能够适应基站移动性的要求。     

移动通信中一种新的位置查询方案及其性能仿真

移动用户的剧增和移动通信业务的发展,对位置管理提出了更高的要求,因此,在移动通信的结构中,设计一个有效的位置管理方案是十分必要的。回顾了针对PCS网络的4种已经存在的位置查询方案,并提出了一种新的查询方案。仿真结果表明,这种新的位置查询方案在性能上要优于4种旧方案。     

空闲状态下信令缩减机制的研究

在移动通信系统中,当多模终端跨系统进行小区重选时,需要进行位置区域更新。如果频繁跨越不同系统,终端会反复进行位置更新,从而使空口和网络产生大量的位置区域更新信令。为了解决这一问题,在LTE/SAE部署初期,引入了空闲状态下信令缩减机制——ISR（Idle State Signaling Reduction）。本文介绍了ISR机制提出的背景,分析了添加ISR机制后的网络架构及ISR机制的关键参数,说明了ISR机制的相关过程。     

UMTS网络位置业务的实现技术

详细探讨了第三代移动通信系统UMTS网络位置业务的定位技术，从多角度比较了各种技术的优劣．并就如何应用这些技术进行了详细的阐述。     

PCS中的移动性管理的发展研究

介绍了个人移动通信系统(PCS)中移动性管理的基本概念，从移动性管理的总体框架、位置管理和切换管理两个主要功能流程方面阐述了PCS中移动性管理的体系结构及移动性管理的实现。详细描述了常见的位置管理方法和切换管理方法及这两方面的改进措施，并对几种PCS中的移动性管理机制进行了分析比较，最后给出了结论。     

移动通信位置管理信令开销及位置区设计优化

指出了位置区设计方案在移动通信网络规划中的重要性，分析了各参数对于位置管理信令开销的作用。同时探讨了位置区及路由区范围、形状等参数变化对不同特征用户群的位置管理信令开销的影响。由此总结出如何针对不同用户特征设计合理位置区的基本原则。     

一种新的动态多目标优化位置区域划分方法

文章基于移动通信网络系统中的位置区域划分问题,介绍了多目标进化算法,并提出了一种新的动态多目标优化位置区划分方法,从理论上分析该方法能有效避免传统算法中不能进行多目标的规划、不能进行全网优化等的不足。     

一种基于移动通信网络的区域客流引导系统设计

为实现区域内人数统计、人员属性分析、未来人数预测等功能,文章提出了一种基于移动通信网络对移动手机位置信号进行处理的区域客流引导系统,阐述了其关键技术和系统设计,最后介绍了其业务扩展应用。     

基于BOSS的HLR容灾方案

归属位置寄存器(HLR)在移动通信网络中具有重要的地位,本文从网络安全及提升服务角度出发,对基于业务运营支撑系统(BOSS)的容灾备份方式进行了分析、探讨,提出低成本的解决方案.     

一种适应微蜂窝的移动性管理策略

在微蜂窝系统中,移动性管理是一个很重要的课题。如果采用传播蜂窝的位置登记的管理方式将会产生大量的系统资源浪费,降低系统的效率。本文提出一种基于用户移动特性（例如呼叫到达率、移动速度和移动位置等特点）的动态位置区的管理方案。在论文中对方案的寻呼代价和位置区修改代价进行分析和讨论,并与传统位置区管理方式〖１〗〖２〗做了比较。     

卫星与地面移动通信系统综合环境下的一种位置管理策略

提出了一种在卫星与地面移动系统综合环境下的位置管理方案，即把两系统相重叠的小区设置为边界位置区(BLA)，漫游用户在BLA中进行位置更新，呼叫到达时，BLA中的位置寄存器配合系统进行寻呼。通过计算和数值分析证明该方案不仅可以使原有两系统结构不发生变化，并且能有效减小位置更新与寻呼造成的系统开销。     

A Location Management Scheme Using Direction Characteristics of Mobile Terminals in Mobile Communication Networks

Recently, as the number of mobile terminals (or users) keeps explosively increasing, the location management to track the mobile terminals in mobile communication networks is becoming more important. However, previous schemes have used static location information without any consideration about the moving direction of a mobile terminal. For a fixed paging area, this results in unnecessary pagings, thus increasing the location management cost. In this paper, we propose a new location management scheme using the direction characteristics of a mobile terminal. The direction vector is defined to represent the moving direction of a mobile terminal and to compute a distance from the cell where a location update occurs to the current cell. The offset operation of direction vectors is also presented to represent the position of a mobile terminal in a paging area. This allows the mobile terminal to determine whether a location update will be performed or not. The mobile terminal can also vary its own paging area dynamically according to its moving direction whenever it moves across its paging area. In addition, we develop an analytical model for the proposed scheme which captures the direction characteristics of a mobile terminal based on the Markov model. Analytical results show that the proposed scheme can reduce location management cost by forming a dynamic paging area along the moving direction of a mobile terminal when compared to other schemes.Ui-Sung Song received his B.S and M.S. degrees in Computer Science and Engineering from Korea University, Seoul, Korea in 1997 and 1999, respectively. He is currently a Ph.D. candidate in Computer Science and Engineering from Korea University. Also, he is currently a researcher in the Research Institute of Computer Science and Engineering Technology at Korea University. His research interests include mobile IP, PCS networks, and ad-hoc networks.Joon-Min Gil received his B.S. and M.S. degrees in Computer Science from Korea University, Chochiwon, Korea in 1994 and 1996, respectively. He received his Ph.D. degree in Computer Science and Engineering from Korea University, Seoul, Korea in 2000. From 2001 to 2002, he was a visiting research associate in the Department of Computer Science at the University of Illinois at Chicago, U.S.A. He is currently a senior research engineer in Supercomputing Center at Korea Institute of Science & Technology Information, Daejeon, Korea. His recent research interests include distributed and mobile computing, wireless networks, Internet computing, P2P networks, and grid computing.Chong-Sun Hwang received his M.S. degree in Mathematics from Korea University, Seoul, Korea in 1970, and his Ph.D. degree in Statistics and Computer Science from the University of Georgia in 1978. From 1978 to 1980, he was an assistant professor at South Carolina Lander State University. He is currently a full professor in the Department of Computer Science and Engineering at Korea University, Seoul, Korea. Since 2004, he has been a Dean in the College of Information and Communications at Korea University. His research interests include distributed systems,distributed algorithm, and mobile computing systems     

Load-Balanced Location Management for Cellular Mobile Systems Using Quorums and Dynamic Hashing

This paper presents a new distributed location management strategy for cellular mobile systems. Its salient features are fast location update and query, load balancing among location servers, and scalability. The strategy employs dynamic hashing techniques and quorums to manage location update and query operations. The proposed strategy does not require a home location register (HLR) to be associated with each mobile node. Location updates and queries for a mobile node are multicast to subsets of location servers, which change with time depending on the location of mobile node/querying node and load on the servers. Simulation experiments demonstrate that such dynamism prevents situations of heavy load on some location servers when mobile nodes are not uniformly distributed in space, or when some mobile nodes have their location updated or queried more often than others. Also, queries return the latest location information of a mobile node with a very high probability. The proposed scheme requires at most one unicast and two rounds of message multicasting for location update and query operations. All multicast messages have a small payload and are restricted to the high bandwidth wired part of the mobile network resulting in low communication overhead. Moreover, if a quorum of location servers gets overloaded, part of its load can be transferred to another lightly loaded quorum using dynamic hashing techniques.     

蜂窝网络中环状搜索移动性管理策略

位置管理是移动通信领域的一个具有挑战性的问题,涉及到位置更新和位置查找操作.在现行蜂窝系统的位置管理策略(简称"基本策略")中,一旦移动台越区,就需要进行位置更新.由于移动台的越区具有局部性,基本策略会造成系统资源的极大浪费.因此,降低位置管理的费用成为移动通信领域的一个研究热点.该文给出不需要进行位置更新的环状搜索位置管理策略(简称"环状策略"),并推导出搜索位置区平均层数的一个公式,然后利用这一公式对基本策略、指针推进策略与环状策略的费用进行了对比研究,得出:在一定条件下,环状策略的费用要比基本策略及基本指针推进策略小.     

Java-Based Mobile Asset Location

Owing to the way networks grow and the advent of mobile computing, the task of physically locating assets is becoming increasingly complex. Network management tools are usually not suitable for management of dynamically moving assets and provide almost no facilities for asset localisation. In addition, asset management products delegate to human operators the task to identify physical asset's location.JLocator is a Java-based system that allows both static and dynamic assets to be physically localised. Based on SNMP and Java, it enables users to locate assets through a simple web interface and allows asset management systems to take advantage of asset location information provided by JLocator. Finally, its distributed architecture makes it scalable and completely platform-independent.     

Determination of the Registration Point for Location Update by Dynamic Programming in PCS

Location management is important to effectively keep track of mobile terminals with reduced signal flows and database queries. Even though dynamic location management strategies are known to show good performance, we in this paper consider the static location management strategy which is easy to implement. A system with single home location register and pointer forwarding is assumed. A mobile terminal is assumed to have memory to store the IDs of visitor location registers (VLRs) each of which has the forwarding pointer to identify its current location. To obtain the registration point which minimizes the database access and signaling cost from the current time to the time of power-off probabilistic dynamic programming formulation is presented. A Selective Pointer Forwarding scheme is proposed which is based on one-step dynamic programming. The proposed location update scheme determines the least cost temporary VLR which point forwards the latest location of the mobile. The computational results show that the proposed scheme outperforms IS-41, pure Pointer Forwarding, and One-step Pointer Forwarding at the expense of small storage and a few computations at the mobile terminals.     

无线网络控制器的移动性管理功能及其实现方案

本文简要介绍了与移动性有关的第三代移动通信系统的网络特征;通过在ＩＭＴ－２０００功能模型的相关功能实体中引入移动性管理模拟,分析了无线网络控制器的移动性管理功能,并给出了具体的实现方案。