4G核心技术的发展趋势

结合市场导向下的移动新业务发展的重要性,重点论述了第四代移动通信系统发展中涉及的关键技术、发展趋势以及前景的展望。     

CDMA通向3G之路

cdma2000技术是第三代移动通信系统IMT2000系统的一种模式，它是从cdmaOne(IS-95)演进而来的一种第三代移动通信技术。cdma2000标准是一个体系结构，称为cdma2000家族，它被分为多个阶段来实施，第一阶段称为cdma2000-1X,第二阶段称为cdma2000-3X。1X的意思是使用与IS-95相同的一个1.25MHz频宽的载波；3X则意味着3个载波。HDR(High DataRate)的提出是为了进一步满足用户对无线数据通信的需求，它通过更能符合分组数据传输特点的调制方式使系统对数据速率的支持达到了前所未有的2.4Mb/s。凭借其出色的性能，它被3GPP2作为cdma2000-…     

The evolution path of 4G networks: FDD or TDD?

Frequency-division duplexing and time-division duplexing are two common duplexing methods used in various wireless systems. However, there are advantages and technical issues associated with them. In this article we discuss in detail the features, and the design and implementation challenges of FDD and TDD systems for 4G wireless systems. In particular, we present a number of advantages and flexibilities an TDD system can bring to 4G systems that an FDD system cannot offer, and identify the major challenges, including cross-slot interference, in applying TDD in practice. Due to the fact that cross-slot interference is one of the critical challenges to employing TDD in cellular networks, we also provide a quantitative analysis on its impact on co-channel and adjacent channel interfering cells     

Enhancing IP service provision over heterogeneous wirelessnetworks: a path toward 4G

Second-generation mobile radio systems have been deployed successfully worldwide and have evolved to higher data rates and services. Third-generation mobile radio systems are currently starting to be developed in different regions of the world. Today, the open question is how the third-generation systems will evolve. It is very likely that fourth-generation systems will not be a single standardized air interface, but a set of different technologies and standards. In particular, wireless LAN/wireless PAN type systems are designed for high/medium-data-rate access, low range, and, in general, low mobility. They are applicable to corporate networks and public access as a complement to cellular mobile radio systems for hot spot applications such as airports, hotels, and campuses. In this specific WLAN/WPAN framework and to guarantee an agreed QoS provision over such infrastructures, we propose a solution based on the wireless adaptation layer approach. In particular, aspects related to wireless link impairments and traffic requirements are approached by the implementation of configurable, modular software that is adapted to the specific conditions and needs of the particular wireless infrastructures     

3G发展趋势展望

首先从中国与欧洲国家发展3G的三个方面的不同,讨论了中国如何发展3G;接着讨论了TD-SCDMA的优势与特点;最后对3G和TD-SCDMA的前景进行了预测。     

Technologies Assisting the Paradigm Shift from 4G to 5G

Recent research in Mobile Ad-hoc Networks mostly deals to minimize the congestion in the network. In this regard, a variety of query-broadcast techniques have been proposed, and employed to reduce routing overhead such as the congestion, route-latency and energy-consumption. Such techniques mainly focus on reducing unnecessary propagation of route-query by repealing the query-broadcast. In our research findings, we found these repealing techniques have extra routing-overhead of chasing the route-query thus increasing energy-consumption and slowing down the route-discovery. In particular, this motivates us to propose a cache-aware broadcasting technique. In order to evaluate the proposed technique, the critical and analytical assessment is done in terms of query-diffusion, route-latency, packet-delivery ratio and energy-consumption ratio.

     

Challenges in the migration to 4G mobile systems

With the rapid development of wireless communication networks, it is expected that fourth-generation mobile systems will be launched within decades. 4G mobile systems focus on seamlessly integrating the existing wireless technologies including GSM, wireless LAN, and Bluetooth. This contrasts with 3G, which merely focuses on developing new standards and hardware. 4G systems supports comprehensive and personalized services, providing stable system performance and quality service. However, migrating current systems to 4G presents enormous challenges. In this article, these challenges are discussed under the headings of mobile station system, and service aspects. Proposed solutions to the research problems in each aspect are also examined.     

迈向4G面临的挑战

本文首先介绍了第四代移动通信系统的基本特征,随后从移动终端、系统和业务3个方面来分析目前4G研发面临的挑战,同时简要介绍了这3个方面目前的研发现状和相关的解决方案.     

移动通信系统从1G到4G的演进

第2代(2G)的数字移动通信由单纯的语音通信转移到提供语音、图像、文字等综合信息的传输,并能无线接入因特网.2G系统的传输速率难以满足人们对移动多媒体信息以及移动数据传输的需求.3G的核心网是从2G演进而来,但并不是传输TCP/IP数据包的最优结构.4G系统将是基于TCP/IP的核心网,混合OFDM和CDMA的无线接入方式,分离的接收、发射基站,基于无线ad hoc网络的结构而非蜂窝结构.     

向第四代移动通信系统演进的关键技术

4G移动通信系统可将现有的无线技术(包括GSM、无线局域网和蓝牙技术等)无缝地连接在一起，这与集中精力发展新的标准和硬件的3G不同。4G系统将支持广泛的．个性化的服务，提供稳定的网络性能和服务质量，然而将现在的网络向4G演进会面临巨大的挑战。文章将分别从移动台、系统和业务三个方面来介绍面临的这些挑战并介绍已经提出的解决这些问题的方法。     

A framework for an evolutionary path toward 4G by means of cooperation of networks

Combining networks to form a composite network for joint operations in the current business context is desirable in order to limit capital and operational expenditures, but currently requires complying with existing value chains and business models. However, commonalities between the two most popular infrastructures, mobile cellular and TV broadcast, are such that a common framework for services and QoS management can be built, without the expense of starting from scratch in the design of a universal system able to connect users for communications and entertainment. This article describes such a framework that can potentially ally mobile cellular and TV broadcast platforms as one stepping stone toward 4G and the information society.     

迎合3G时代的TD-SCDMA终端的发展趋势

第三代移动通信系统自提出以后，在几年的时间中发生了根本性的变化，经历了快速发展的阶段。拥有中国自主知识产权的TD-SCDMA移动通信系统在全球3G的浪潮中正在逐步成熟。第三代移动通信系统最显著的特点是宽带多媒体通信和高速数据业务。3G系统能提供多类型的高质量多媒体业务，能实现全球无缝覆盖，具有全球漫游能力并与固定网络相兼容。它可以实现小型便携式终端在任何时候、任何地点进行任何种类的通信。新的移动多媒体业务无疑将成为移动通信产业链未来发展的重要和关键基础之一。     

4G向5G核心网演进发展方案研究

介绍4G向5G核心网演进发展过程中,非独立组网NSA架构和独立组网SA架构的对比分析,以及基于此对比下的演进策略。同时介绍演进过程中的云原生方案、网络管理运维演进方案,提出不同场景下的4G向5G核心网演进部署策略和建议。     

浅谈4G有源室分向5G演进

针对5G(第五代移动通信)网络的覆盖特性,对5G室内覆盖系统建设的必要性、不同室内覆盖系统的优劣势进行比较分析,探讨5G网络下的室内覆盖方式,指出4G(第四代移动通信)有源室内分布系统向5G网络演进的方向,提出现有4G有源室内分布系统的改造建议。     

4G网络体系结构向5G网络演进分析

从网络架构上比较4G网络和5G网络架设的不同理念,从网元组成上指出两者不同的产生方式,从网络接口说明它们不同的工作方式,介绍基于万物互联的5G新技术,从而得出5G是一个全新的网络,相比4G网络有不可比拟的优势.在分析比较的基础上,进一步提出从4G到5G的独立组网和非独立组网的的两种演进方式.     

3G时代通信芯片开发趋势探讨

通信芯片作为半导体行业最为活跃的市场应用之一,其发展趋势一直备受瞩目.本文分析了3G时期通信芯片的发展趋势.     

4G

4G已不遥远,年底前发放牌照身边总不断有消息说4G网络即将来临,可是谣传不断,准确的消息却很少。M1这次带来的消息应该说是比较靠谱的,在9月24日开幕的2013年北京国际通信展会上,工信部部长苗圩在参观华为展馆时对记者表示,4G牌照将于今年年底前正式发放。这可是真正的权威人士消息啊。此前有传闻“5．17”电信日当天会发放4G牌照,不过电信日当天证实该消息是谣传。根据中国移动的4G网络建设计划,