软交换在移动核心网中的应用

计划中的3G移动网正在规范如何从电路交换话音传送向分组话音传送过渡。在这一过渡中,将在移动核心网中引入基于软交换的体系结构。该文主要阐述软交换在3G(包括WCDMA和cdma2000)及2G中的应用、从2G到3G的过渡、在移动网中软交换体系结构的特点和好处。     

网络融合下3G基站接入方案研究

在两张传输网同厂家的前提下,分别依托原移动网传输网、原固网传输网和混合组网三种模式,对网络融合下3G基站接入的组网模式进行了分析与比较。可供运营商本地网3G基站接入模式选择提供一定的参考。     

3G核心网建设方案分析--3G建设初期核心网只建分组域不建电路域

1前言目前预计,3G牌照很可能在2004年发放,3G网络的部署指日可待。由于3G网络投资较大,涉及到移动运营商未来发展战略,故3G网络建设的方式和步骤需要根据当地的实际情况进行详细的探讨,本文主要针对中国移动的情况进行分析。在3G核心网方面,就WCDMA标准而言,各省移动往往同时新建分组域和电路域,在3G网络中同时实现对3G话音和3G数据业务的支持。实际上,由于话音业务目前完全可以由2G网络承载,在近期,在部分省份建设3G核心网时可以有选择的只建设分组域,而不建电路域。2单独建设的可行性2.1技术的角度从基本的承载网络来看,2G网络承载…     

走向IMS的PS域核心网规划建设方案

在3G牌照正式发放之前，我们仍然需要为新一轮大规模网络建设继续做准备。3G网络和现有2G网络如何互连互通，数据用户如何在3G网络和2G网络之间进行无缝连接，如何使系统网络方便地演进到IMS构架，这些问题都需要大家思考。一个经济有效且易于演进的网络结构，将对运营商顺利开展新一代移动业务，快速抢占发展的制高点，起到相当关键的作用。     

移动网络的未来：全IP移动网

首先介绍全IP移动网的背景和含义，然后从核心网和接入网两个方面介绍3G网络中的全IP技术，最后介绍全IP移动网的发展方向。     

诺基亚3G解决方案——实现三代市场最大收益

诺基亚第三代移动通信系统的核心网是基于3GPP R4规范的系统。无线接入网络通过Iu接口连接到核心网，电路交换的数据通过Iu-CS接口连接到MGW和MSC Server，诺基亚MSC Server将同时支特Iu-CS接口和现有的A接口。分组交换的数据通过Iu-PS接口连接到SGSN，新的大容量3G SGSN将支持Iu-PS接口，所有其它的GPRS网元都将同时支持GPRS和3G。     

构建3GPP R4电路域核心网

如今IP已成为移动通信网络的发展趋势,3G无线通信网络将采用以IP为核心的骨干网传送基于IP的数据和语音新业务,其健壮而高效的3G核心网络结构有利于推动无线网络的增值服务和功能的增加。因此在部署3G网络时,核心网的建设很关键。而采用任何新型网络,都不可能对原有网络全盘否定,从网络运营的角度来说,最好采用渐进式的、平滑式的过渡方式完成,最大限度地利用和保护投资者的利益。文章针对国内运营已存在的电路和分组网络情况,提出了不同的R4核心网电路域的建网方案。     

无线互联网的心脏:迈向未来的分组核心网

当今,与3G相关的讨论一直十分热烈,基中,无线接入网络占据了大量的篇幅,关于UMTS,cdma2000和TD-SCDMA等技术的讨论详尽而且深入。     

S3G标准的演进

1 前言由于IP数据业务的快速增长,3G移动网所使用的分组交换技术需要增强。为保持在性能和成本方面的竞争力,则需要系统级的连续演进和优化。这种长期演进的主要目标包括减少系统时延、提高用户数据率、提高系统容量和覆盖、降低成本。ITU将100Mb/s速率以下的技术称为增强型3G技术(Enhanced 3G),100Mb/s以上的速率被叫做新的无线接口技术。国际标准组织3GPP将这种技术叫做     

关于我国3G移动网建设的若干设想

目前,我国3G实验和外场测试正在积极进行中,业内关于3G移动网建设的讨论十分热烈。出于种种因素的考虑,信息产业部对3G服务的商用相当谨慎,至今未明确3G牌照的发放时间。本文将提出关于我国3G移动网建设的若干设想,希望对问题的解决有所帮助。     

连接状态下LTE接入系统内的移动性管理

3GPPLTE是基于OFDM和MIMO技术并针对当前3G系统的长期演进计划,对3G系统的网络结构和无线接入技术进行了较大的改进。文章详细分析了连接状态下LTE接入系统内的移动性管理,将双播技术作为一种保证数据无损的机制引入到LTE中,并与现在应用于LTE中的数据转发技术进行了比较性研究。     

基于IP无线网络中的移动性

基于IP的无线网络将成为下一代移动网络的核心。在全IP无线网络中。移动性对于多媒体应用起着十分重要的作用。探讨了基于IP的无线网络中的一些重要问题，包括移动IP、移动IPv6和其它相关的一些技术。同时还讨论了WLAN、WWAN、2G以及3G蜂窝网和下一代混合移动网络中关于移动性支持等问题。     

3G/4G系统间互操作技术探讨

本文对4G引入后的空闲态重选、数据业务互操作方案进行了分析和研究。提出了面向4G商用网络的3G/4G互操作测量制定原则和相关建议。     

TDD-CDMA for the 4th generation of wireless communications

This article discusses an evolutionary TDD mode of CDMA-based path for 3.5G/4G systems. This technology has already been the basis of two 3G standards: TD-CDMA and TD-SCDMA with a synchronous uplink. Several techniques have been developed that allow TDD-CDMA-based systems to transmit at rates usually associated with 3.5G to 4G, up to 10-20 Mbit/s with wide area coverage. The present TDD-CDMA-based 3G standards are evolving to provide these higher rates, while fully retaining the coverage and mobility associated with, and expected from, the present mobile communications systems. This article discusses how TDD-CDMA specific techniques facilitate delivering services at data rates associated with 3.5G and 4G. We review how TDD-CDMA can provide for asymmetric uplink and downlink transmissions, facilitate deployment of advanced antennas for improved downlink coverage, and enable provision of advanced receiver techniques in base stations and mobiles. We also discuss how these techniques affect systems capacity in full packet-switched IP-based systems. We then discuss 4G TDD CDMA systems: those with different modulation techniques for uplink and downlink communications. These are generally based on a multicarrier mode of CDMA, and may incorporate OFDM technique.     

Mobility support across hybrid IP-based wireless environment: review of concepts, solutions, and related issues

The 4G or Beyond 3G wireless networks is consist of IP-based heterogeneous access networks from 3G cellular, WiFi, WiMAX to other emerging access technologies such as mesh networks. The key objective of designing the next generation wireless networks is to support of mobile subscribers. To support the mobile host in the hybrid wireless access technologies, many solutions based on network protocol stack have been proposed in the literature. In this article, after review of mobility concepts, a special attention is given to some of the mobility management methods as well as handover techniques across various wireless access networks. We have also compared the major mobility protocols in each layer for their features. Finally, some of the open issues that needed to be addressed in mobility management protocol in the next generation wireless networks are outlined.     

Services in interworking 3G and WLAN environments

Interworking WLANs and 3G mobile networks are expected to provide ubiquitous wireless communications at high data rates and a large variety of services with variable bandwidth and QoS requirements, across a wide range of propagation environments and mobility conditions, using dual mode terminals. The interworking of the two networks is a major step toward a new generation of wireless networks in which other radio technologies are also be integrated. In this article we present possible architectures that enable the interworking of 3G and WLAN networks. We then address the capabilities of various terminal types and describe future services in the interworking environment. Finally, we present market forecasts on terminal and service demand growth.     

User-Centric Offloading to WLAN in WLAN/3G Vehicular Networks

In recent years, there has been a growing demand in 3G data services, leading to deteriorating 3G service quality. Noting that Wireless Local Area Networks (WLANs) as well as 3G cellular networks are widely available today, WLANs could be effectively utilized to relieve the overload in the 3G networks. On the other hand, use of IEEE 802.11 WLAN Access Points (APs) has proliferated tremendously, resulting in a communication device inside a mobile vehicle to access the Internet. However, using Internet through APs in moving vehicles is challenging since WLAN APs have a short range and are typically not deployed to cover all roads. Several studies have investigated the performance of using intermittently available WLAN connectivity from moving vehicles for data transfers and predictive offloading in WLAN/3G networks. However, these works have not addressed mobility pattern from the viewpoint that drivers’ mobility is generally known to have a daily routine. Therefore, in this paper, we consider the user’s historical mobility to decide to offload data to WLAN instead of switching to 3G network. The user’s application usage pattern is also considered into predicting available WLANs. To evaluate the performance of our offloading algorithm, we analyze the prediction error and conduct simulations. The simulation results show that the proposed algorithm achieves shorter transmission time than the existing schemes that do not consider user’s mobility pattern by delivering more data to the WLANs.     

Mobility management in third-generation all-IP networks

It is now widely recognized that using IP as the foundation for next-generation mobile networks makes strong economic and technical sense, since it takes advantage of the ubiquitous installed IP infrastructure, capitalizes on the IETF standardization process, and benefits from both existing and emerging IP-related technologies and services. The large-scale support of data services and their integration with legacy services are the common objectives of all wireless efforts termed third generation (3G) and beyond. In these all-IP wireless networks, IP can be deployed in two modes: the transport mode and the native mode. As we show in this article, this duality in the use of IP has a significant impact on network efficiency and performance. It is the extended native use of IP in the terrestrial segment of a wireless operator's domain that more readily allows for building a converged network with multiple access technologies. We then discuss the different levels of mobility in the all-IP network. In particular, our focus is on micromobility, and on the issue of seamless localized mobility within the converged network. After reviewing the mobility schemes that have emerged in previous years, we describe a hierarchical mobility management scheme based on multiprotocol label switching (MPLS). The scheme employs an enhanced type of MPLS routers, called label edge mobility agents, and is scalable, efficient, and flexible. It directly inherits the noted capabilities of MPLS in terms of support of QoS, traffic engineering, advanced IP services, and fast restoration. This scheme does not use nodes that are specific to any given wireless technology, and is well suited for gradual deployment     

上海贝尔2G／3G互操作解决方案

分别从互操作策略选择、有效的无线网络移动性管理功能和优化经验与合理的参数设置等3个方面讨论了如何定位2G／3G网络相互关系,协调互操作,完善用户的移动性,提高设备网络利用率,保证良好的用户体验。并简要介绍了上海贝尔在2G／3G互操作方面的一些想法和建议以及产品功能特点和优势。     

基于GPS/3G物流运输车数据采集终端的设计

针对物流行业对运输车辆高质量的管理需求,结合GPS全球定位、3G无线通信、温度传感器、数据处理等相关技术,设计了一款应用于物流运输车的数据采集终端.实测表明,该终端能准确测量出刹车温度、经纬度、车速、定位模式等相关参数,并能实现实时数据上传、VoIP网络电话和实时通信等功能,在物流行业中得到了良好的应用.