基于GPRS／UMTS网络的无线Internet接人及MIP技术在其中的应用

随着GPRS/UMTS网络的即将投入商用和Internet网络及其业务的飞速发展 ,如何将这两种通信网络进行合理的融合以利用两者的不同优势实现更加快捷方便的网络服务越来越受到包括网络运营商 ,设备供应商乃至理论研究界的广泛关注。本文就这一课题详细介绍了目前通信业界的最新相关研究成果 ,并讨论了MIP技术在这一融合过程中的积极应用。     

Provisioning of VoIP services for mobile subscribers using WiFi access network

This article proposes a solution for two issues in current communications. Firstly, that IMS suffers from lack of clients. Secondly, that mobile operators want to give the subscriber a possibility to access their VoIP network and efficiently cover special, densely populated areas like airports. To address these problems, we have developed a novel service architecture, which allows 2G subscribers access to a SIP based VoIP network via WiFi complying security standards. User authentication and authorization is based on the EAP-SIM algorithm. Integrity and confidentiality is provided by IPSec connection established using parameters derived from authentication triplets. Consequently, all security-related issues can be performed exclusively using the Subscriber Identity Module (SIM). We have tested and verified the proposed architecture with a mobile phone and have proven the correctness of our approach. The main drawback that remains is the difficulty of IPSec implementation that can be bypassed by a special application.     

Wireless LAN access network architecture for mobile operators

The evolution of IP-based office applications has created a strong demand for public wireless broadband access technology offering capacity far beyond current cellular systems. Wireless LAN access technology provides a perfect broadband complement for the operators' existing GSM and GPRS services in an indoor environment. Most commercial public wireless LAN solutions have only modest authentication and roaming capability compared to traditional cellular networks. This article describes a new wireless LAN system architecture that combines the WLAN radio access technology with mobile operators' SIM-based subscriber management functions and roaming infrastructure. In the defined system the WLAN access is authenticated and charged using GSM SIM. This solution supports roaming between cellular and WLAN access networks and is the first step toward an all-IP network architecture. The proto-type has been implemented and publicly verified in a real mobile operator network     

移动Ad Hoc网络基于IPv6的Internet接入技术研究

针对实现移动用户无线上网的需求，通过对移动AdHoc网络的体系结构和路由技术的研究，以及对移动IPv6协议的工作原理及其与IPv4特性的比较分析，提出了AdHoc网络基于IPv6的Intemet接入方法，并对其地址自动配置、路由发现、网关发现、协议转换和分组转换等关键技术进行了分析，同时针对这两种技术相结合存在的广播和多跳问题提出了改进方法，并对今后的工作进行了展望。     

Unified Mobility Manager: enabling efficient SIP/UMTS mobile network control

Internet telephony is viewed as an emerging technology not only for wireline networks, but also for third-generation wireless networks. Although IP end to end is considered the ultimate approach to future wireless voice services, there is still a long way to go before IP voice packets can be effectively transported over the air. Therefore, Internet telephony and today's circuit-switched wireless network will coexist for years to come, and it is essential to effectively perform interworking between these networks. This article proposes the Unified Mobility Manager (UMM) that achieves efficient interworking between traditional wireless networks and Internet telephony networks. The main characteristic of the UMM is that it combines UMTS HLR and SIP proxy functionality in one logical entity, which helps eliminate the performance degradation due to interworking between SIP and UMTS. This article identifies seven potential network architectures with and without the UMM and with varying degrees of IP penetration in the wireless core networks, and performs comparative analysis in terms of their call setup signaling latency. Our performance results show that for SIP originated calls, the architecture with the UMM can achieve better performance than existing UMTS networks without the UMM. Our results further show that when the backbone network is fully IP-enabled, dramatic performance gains can be accomplished with the UMM for PSTN originated calls as well as for SIP originated calls. The article also demonstrates that the UMM allows graceful migration from today's circuit-switched wireless networks to hybrid SIP/circuit-switched wireless networks, and toward the IMS architecture for all-IP UMTS networks in the future.     

基于GPRS网络的移动数据接入终端的设计

本文针对当前很多行业的传统数据终端需要远程联网的要求，结合当前最新的嵌入式技术．移动通信技术和Internet网络技术，利用ARM7系列的微处理器和西门子最新的GPRS模块MC35i，基于Ljnux操作系统开发平台，设计并实现了移动数据接入终端，内嵌TCP／IP协议，能轻松方便地通过GPRS网络接入互联网，进行远程无线数据传输。而且用户接入因特网无需进行认证，可以由移动用户鉴权替代，这样可以加快用户接入速度。该终端可以广泛地应用于运输业．金融．证券、机房监控和远程维护管理系统、移动车辆监控调度系统和城市公用事业实时监控维护系统等领域。     

基于GPRS网络的移动数据接入终端的设计

本文针对当前很多行业的传统数据终端需要远程联网的要求,结合当前最新的嵌入式技术、移动通信技术和Internet网络技术,利用ARM7系列的微处理器和西门子最新的GPRS模块MC35i,基于Linux操作系统开发平台,设计并实现了移动数据接入终端,内嵌TCP/IP协议,能轻松方便地通过GPRS网络接入互联网,进行远程无线数据传输.而且用户接入因特网无需进行认证,可以由移动用户鉴权替代,这样可以加快用户接入速度.该终端可以广泛地应用于运输业、金融、证券、机房监控和远程维护管理系统、移动车辆监控调度系统和城市公用事业实时监控维护系统等领域.     

用于移动Internet随机接入的一种新方式

介绍了移动通信网络中随机接入的概念，论述了移动Internet随机接入的特点，提出了基站调控的slotted-ALOHA随机接入方式，并从理论分析和计算机仿真两方面与现行的移动通信随机接入方式进行了对比，表明该方式能显著提高随机接入性能，使用代价微小，易于实际应用。     

UMTS接入安全研究

本文主要介绍了UMTS的接入安全,重点介绍了身份识别、鉴权、完整性保护和加密等安全机制,并对其特点进行了分析,对未来发展趋势进行了展望。     

基于运营商核心能力的移动数据上网行为管控

在4G时代手机上网成为人们日常生活的主要活动,但对于自控能力较弱学生等群体存在普遍的上网管控需求。传统的上网管控方案需要依赖特殊定制的终端和特殊的APP软件,存在硬件依赖强、成本高、易破解、可推广性差等缺点。本文分析了运营商HLR和PCC等核心能力,并提出了基于PCC限速技术的移动数据上网管控方案。通过结合APP端和Web端管控平台,实现灵活可自定义的限速规则,可同时满足家长和学校的管控需求,具有推广成本低、用户体验好等优点。     

Video transcoding proxy for 3Gwireless mobile Internet access

Transcoding proxies for mobile World Wide Web access have been developed. In the near future, wideband mobile communication systems such as IMT-2000 will emerge, and these proxies will have to cope with a variety of media such as video. In this article we identify issues involved in viewing a video stream in a mobile computing environment; to handle these issues, we propose a video transcoding system and its control method. These mechanisms provide stable transmission of video data and comfortable video viewing on user clients by estimating the communication conditions, client device capabilities, and user preferences     

移动互联网中网络访问优化策略的研究

随着移动互联网的快速发展,在3G时代,移动终端(GPRS/3G)上网用户数量已经超越了传统PC上网的用户数量,移动终端上网已成为最为普遍的网络应用之一。但是,目前制约移动终端上网发展的最大因素就是数字业务流量费较高及移动终端访问网络速度较低。因此,如何提高移动终端上网速度、减小流量就成为一个非常重要的问题,现针对WAP手机网站的体系结构及其特点,研究WAP网站的配置,提出WEB网站优化的框架结构以及移动互联网中网络访问优化策略。     

Towards passive cooling solutions for mobile access network

The amount of electricity used by mobile networks has become an important issue in recent years as demand for new services has become more widespread. In 2006, energy consumption of Orange mobile network was estimated at 290?GWh per year. Recent works show that thermal architecture must be improved in order to increase thermal efficiency of buildings, shelters, and outdoor cabinets. This paper shows some new approaches on thermal management for telecom enclosures in order to reduce energy consumption of this network.     

Stubby monopole antenna for UMTS/WLAN dual-mode mobile phone

A novel stubby monopole antenna for mobile phone applications is presented. The antenna is easily fabricated by bending a single metal plate. Further, the antenna shows a wide operating bandwidth of about 6 GHz (about 1.7-7.8 GHz), making it easy to cover the UMTS band and the 2.4/5.2/5.8 GHz WLAN bands for mobile/WLAN dual-mode operation of a mobile phone     

共用集群通信网的路应如何走

1 公众移动通信网与专用移动通信网的区别 移动通信从应用方面可划分为公众移动通信网和专用移动通信网。公众移动通信网俗称移动电话,是以为公众提供移动通信业务为目的而建立和经营的网络,供个人使用。专用移动通信网俗称集群电话,它是指某一业务部门如公安、铁路、交通、城市管理等部门作为生产调度、行政管理、抢险救灾、应急救援而建立的综合无线调度移动通信网络,供生产一线的专业人员使用。在专用移动通信网中,又可划分为两大类的集群移动通信网：一类是共用调度集群移动通信网(Public Access M0bile Radio),简称PAMR,另一类是专用集群移动通信网(Private Mobile Radio),简称PMR。共用调度集群移动通信网是指许多专业部门在同一覆盖区内共用频率、共用设备、集中管理和维护的移动通信网。专用集群移动通信网是指某一个部门,如国家安全、公安、军队、铁路等部门使用的集群移动通信系统。由于应用范围的不同,要求的网络结构、技术特性和使用功能是有区别的。     

基于移动通信网络的承载与接入技术

随着国内通信市场的不断发展,国内各通信运营商逐渐从单一业务转向多种业务,通信网络也朝着宽带化、多媒体化、IP化、接入多样化等方向发展.主要介绍移动网络针对通信市场的深入开发所提出的业务承载及网络接入技术,以提升移动网络覆盖面和业务承载能力,实现提高移动通信网络服务质量的目标.     

基于AAA认证的仓储移动网络安全关联转移方案

提出基于AAA认证的移动网络(NEMO)安全预接入通告方案,由无线传感器定位信息预判切换,触发安全关联等上下文转移,并告知对端节点或对端服务器的数据处理中心,提前实现安全验证。用?演算建模以保证与现有NEMO安全机制兼容。理论分析知其减少的不当路由开销可达一半,模拟显示延时和资源占用大为降低。     

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.     

移动无线互联网接入中视频编码率控制策略

建立了用于移动无线互联网接入的视频编码转换模型,提出了自适应运动矢量估值方法.将编码转换码率控制分为图像层控制和宏块层两级,首先在总体上对每帧图像的编码比特数进行预分配,然后采用小波变换系数来表征图像特征,为帧内不同特征的宏块选用不同的量化因子,提出了一种新的码率控制策略.模拟实验表明:该方法在视频图像质量没有明显失真的前提下,提高了视频编码转换速度;编码转换输出码流和编码转换缓冲区占用量较稳定,重建图像的信噪比得到了明显的改善.