一种自适应位置更新方案

在移动通信的位置更新过程中,传统的静态位置区方案存在着缺乏变化的灵活性、边界振荡、信令负载过于集中等问题,本文提出了一种新的自适应位置更新方案,采用不同级别的位置区,位置区的选择根据移动台当时的移动和呼叫情况,按照使位置更新和寻呼的无线信令总代价最小的原则确定.该方案可有效地解决静态位置区的各种问题,并能方便地与其它位置区方案切换.     

MSC POOL核心网性能分析

为了减少移动核心网的信令链路负荷,提高资源利用率,提出了一种核心网的组网方案。通过MSC POOL组网实现该方案,并对接入到MSC POOL核心网中的随机移动用户建立概率模型,利用泊松概率分布模型对MSC POOL网络进行理论定性分析和实验。实验结果表明,与传统组网相比,该方案降低了网络负载率,提高了切换成功率和位置更新成功率,对于移动网络结构和性能有着整体的提升。     

区域注册移动IP中的分布式位置管理方案

提出了一种区域注册移动IP的分布式位置管理方案。该方案基于区域网络逻辑上分层的结构特点,提出了在流量负载不超出一定流量门限的前提下,为移动节点选取不同层次上的外地代理FA作为网关外地代理GFA。通过对一种区域网络模型的研究,分析了不同层次上的FA作为GFA时的信令开销。最后通过仿真计算得出了采用分布式位置管理方案时区域注册移动IP信令开销的数值结果。通过分析比较说明该方案相比于区域注册移动IP而言,可以节约10％以上的信令开销,并将有效流量分配山多个GFA承担,当某个GFA失效时将不会影响其它GFA工作,提高了网络的稳健性。     

2G网络复制卡双活和防范技术

现网中有时会出现具有相同IMSI(国际移动用户识别码)和MSISDN(移动台国际移动用户识别码)的SIM卡用户在不相同的MSC/VLR(移动交换中心/拜访位置寄存器)都有注册信息的情况,这种故障现象称为复制卡双活。文章讲述2G网络SIM卡复制原理,介绍导致复制卡双活的主要信令流程,并对复制卡产业链进行分析,最后对复制卡双活的防范措施做出总结。     

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。     

上海移动针对位置更新成功率偏低问题的处理案例

位置更新过程由移动终端发起,一般位置更新的失败率在10%以内,造成位置更新失败的原因多为无线链路故障、HLR无用户数据、网络传输故障等,单个LAC区位置更新成功率下降30%基本可以认定为异常。本文通过中创信令监测系统数据,针对上海移动网络发生的位置更新指标恶化进行深入分析,定位了产生位置更新失败的终端型号。     

移动通信网中的一种边界关联位置更新策略

本文针对移动通信蜂窝网固定位置区位置管理中存在的两个主要问题:边界乒乓效应和边界信令集中,提出了一种边界关联位置更新策略,能够在很大程度上抑制乒乓效应,同时,部分平滑了位置区边界的信令负荷.采用随机游走模型和状态转移矩阵理论推导的方法,对本文提出的更新策略与传统位置更新策略进行了分析比较,并通过仿真进一步验证了结果.分析和仿真表明,本文策略不仅相对易于实现,而且极大优化了性能.     

一种基于位置更新机制的WCDMA用户屏蔽选通系统实现方案

提出了一种基于位置更新机制的WCDMA用户屏蔽选通系统实现方案。该方案利用WCDMA小区重选、身份识别和位置更新的机制,通过建立虚拟小区,诱使用户发起小区重选。通过控制信令流程,在用户位置更新过程中发起身份识别过程,获得用户的身份信息,并通过伪造位置更新回复信令,实现对覆盖范围内用户的通信屏蔽与选通。WCDMA用户屏蔽选通系统在不影响用户正常通信情况下,屏蔽非法用户的通信,可以有效应对WCDMA移动网络违规使用所带来的安全隐患。     

一种移动终端完备身份信息的识别方案

提出了一种基于GSM基站技术对移动终端完备身份信息的识别方案。利用GSM网络的单向认证特性以及位置更新原理,设计了一种多次对终端不同类型身份请求的机制。模拟基站利用空中接口实现与移动终端交互信令,完成对包括TMSI、IMSI、IMEI及IMEISV在内完备身份信息的识别。该方案在网络原有VLR发生数据丢失,TMSI不可用时,能有效对终端的其他身份信息进行获取识别。测试表明,系统可以有效地对基站管控范围内终端的各类身份信息进行准确地识别与管理。     

移动位置业务在3G网络中的实现

移动位置业务作为一种移动增值业务,随着3G技术的发展越来越受到关注。叙述了移动位置业务中采用的主要定位技术并进行综合比较,通过描述该业务的网络架构和基本信令流程,说明该业务在3G网络中的实现方案,展望移动位置业务的发展前景,并指出影响业务发展的关键因素。     

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。     

Movement-based location update and selective paging for PCSnetworks

This paper introduces a mobility tracking mechanism that combines a movement-based location update policy with a selective paging scheme. Movement-based location update is selected for its simplicity. It does not require each mobile terminal to store information about the arrangement and the distance relationship of all cells. In fact, each mobile terminal only keeps a counter of the number of cells visited. A location update is performed when this counter exceeds a predefined threshold value. This scheme allows the dynamic selection of the movement threshold on a per-user basis. This is desirable as different users may have very different mobility patterns. Selective paging reduces the cost for locating a mobile terminal in the expense of an increase in the paging delay. We propose a selective paging scheme which significantly decreases the location tracking cost under a small increase in the allowable paging delay. We introduce an analytical model for the proposed location tracking mechanism which captures the mobility and the incoming call arrival patterns of each mobile terminal. Analytical results are provided to demonstrate the cost-effectiveness of the proposed scheme under various parameters     

Dynamic mobile user location update for wireless PCS networks

The basic architecture of a personal communication network consists of a wireline network and mobile terminals. Each mobile terminal communicates with the wireline network through a nearby base station. In order to route incoming calls to a destination mobile terminal, the network must keep track of the location of each mobile terminal from time to time. This is achieved bylocation update such that each mobile terminal reports its current location to the network at specific time points. When an incoming call arrives, the network will page the mobile terminal starting from the last updated location. A trade-off, therefore, exists between the frequency of location update and the number of locations paged in order to track down the mobile terminal. This paper introduces a location update policy which minimizes the cost of mobile terminal location tracking. A mobile terminal dynamically determines when to update after moving to a new cell based on its mobility pattern and the incoming call arrival probability. The performance of this scheme is close to that of the optimal policy reported earlier. However, the processing time requirement of this scheme is very low. The minimal computation required by this scheme enables its usage in mobile terminals which has limited energy supply and computational power.     

Mobile user location update and paging under delay constraints

Wireless personal communication networks (PCNs) consist of a fixed wireline network and a large number of mobile terminals. These terminals are free to travel within the PCN coverage area without service interruption. Each terminal periodically reports its location to the network by a process calledlocation update. When a call for a specific terminal arrives, the network will determine the exact location of the destination terminal by a process calledterminal paging. This paper introduces a mobile user location management mechanism that incorporates a distance based location update scheme and a selective paging mechanism that satisfies predefined delay requirements. An analytical model is developed which captures the mobility and call arrival pattern of a terminal. Given the respective costs for location update and terminal paging, the average total location update and terminal paging cost is determined. An iterative algorithm is then used to determine the optimal location update threshold distance that results in the minimum cost. Analytical results are also obtained to demonstrate the relative cost incurred by the proposed mechanism under various delay requirements.     

Hierarchical Group Location Tracking for Transportation Systems in Wireless Personal Communication Networks

A hierarchical group location tracking (HGLT) based on grouplocation tracking and hierarchical location update is proposed toreduce the location management cost for terrestrialtransportation systems (TSs) in personal communication networks. A global group location update (GGLU) and a local group locationupdate (LGLU) are performed to provide an accurate position for auser. The GGLU informs a virtual visitor location register of thecurrently camped-on location area and the LGLU informs the servingmobile switching center of the currently camped-on cell. Althoughthe LGLU is done each time a TS moves into a new cell, it causessmall increment in the signaling cost due to localized updates andgroup updates compared with the previous group location trackingscheme. The proposed scheme significantly reduces the paging costbecause the scheme pages only a camped-on cell using the LGLUinformation. Compared with the previous schemes, the HGLT reducesthe location management cost, and it is more efficient as thecost for paging a cell increases.     

低轨卫星系统中结合时间和移动的位置更新策略

低轨(LEO)卫星快速运动,移动终端(MT)相对于卫星的位置信息也在不断变化,如何有效地管理MT的位置信息,减小位置更新频率和寻呼开销是研究位置管理的主要目的。为此,提出一种低轨卫星系统中的动态位置管理策略,基于时间和移动相结合进行位置更新,在不增加寻呼开销的条件下,减小了位置更新频率,从而有效降低了位置管理的总开销。     

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.     

An Enhanced Location‐Based Location Update Scheme in Mobile Cellular Networks

In this study, we consider a location‐based location update (LU) scheme. We propose an enhanced LU (ELU) scheme that can store more cells to reduce the location update cost of the LU scheme and show that the ELU scheme always outperforms the LU scheme. Our scheme can be easily implemented in actual cellular systems.     

小区分层依概率寻呼的位置管理策略

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.我国及其他国家目前正在使用的个人通信网络中,基本的位置管理策略(简称"基本策略")的位置查找操作采用的是,在整个位置区中同步寻呼移动台.由于所要寻找的移动台只在由众多小区所组成的位置区内的一个小区中,因此,"基本策略"会造成系统资源的极大浪费.本文给出一种对位置区内的小区进行分层,按移动台在各层小区的概率从大到小的次序,逐层进行寻呼的位置管理策略(简称"分层策略").在假定移动台在各个小区的逗留时间是符合一般概率分布的随机变量的条件下,推导出移动台处于各层小区的概率及"分层策略"所需搜索的小区平均个数公式.证明了"分层策略"的位置管理费用不大于"基本策略".     

Group location management for mobile subscribers on transportation systems in mobile communication networks

We propose a new location tracking scheme for subscribers on transportation systems (TSs) in which a large number of fast-moving users have the same location as the TS. The group location tracking (GLT) scheme in which a group location update is performed instead of the IS-41's individual location update has been proposed. We propose a distributed GLT (DGLT) scheme based on several virtual visitor location registers (VVLRs) and representative identities. We analyze the GLT and DGLT schemes in view of the database (DB) access cost as well as the signaling cost under one-dimensional network architecture. Compared with the IS-41 scheme, the schemes based on group management generally have a lower signaling cost and a lower DB access cost due to a significant reduction in the number of location updates. As user mobility increases or the number of users on a TS increases, the performance of the group management schemes improves. The DGLT scheme, in which a corresponding home location register selects a closest VVLR among several possible VVLRs, generally has a lower signaling cost although a DB access cost is increased slightly compared with the GLT scheme. We also obtain the regions in which the DGLT is more efficient than the IS-41 and the GLT scheme. The DGLT scheme is an appropriate solution for high signaling cost systems and the GLT scheme is useful for high DB access cost systems.