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移动通信技术的发展

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维普资讯 http://www.cqvip.com

技 圈圈 IIIl 移动通信技术的发展 The Development of Mobile Communications Technologies 摘要本文夼绍了移动通信GsM、COMA、智 髓光海 ZHANG Guang-hai 能网 5G等技术,并探讨了这些技术的发 一中国穆动通信集团 司北京108053l 展。 fChinamobile c0mmunlcali0n8,Beijing 100(153) Abstract:This paper introeced Ihe technologies of GSM.CDMA,IN and 3G etc.,and disc ̄lssed the de- ve{oprnent of mese technologies 1 Introduction 关键词:移动通信 同络技术;智能网;5G As is known to all,mobile communications began its de— Key words:mobile c0mmunIcat.0n.network velopment in 1 980s Now the growth rate of mobile commu— technology.IN(intelligent ne ̄ork).3G nications has surpassed that of fixed network.and has got a 中图分类号(CLC number):TN929 5 great popularity Up until now,the total number of mobile 文献标识码(Documentcode):A users has exceeded 400 million in the world and people’s de— 文章鳊亏(Article lD): mand in this respect i s pushing forward the further develop— 1009—9336(200 ̄ )02一O034一O9 merit of mobile communications.Mobile communications thus far have undergonc two generations,i c,the 1G analog sys— 1 引言 tem in the l 980s and the 2G digital narrowband system in the 众所周知,移动通信是在20世纪80年 1990s.In recent years with the broadband technology pop— 代开始发展起来的,移动通信发展速度远超 ping up as a promising solution in wireless communications. 过固定网络.已得到相当的普及。全球移动 the mobile communications system js evolving toward the so— 通信用户已经超过4亿。人们对移动通信的 called CDMA—based and broadband 3G.This paper ju st sets 需求推葫了移动通信发展,至今移动通信走 out to deal with mobile—related technologies and explores their 过了二代甑经历,即80年代的第一代模拟 development 技术和90年代的第二代窄带数字技术。近 2 GSMvs.CDMA 些年来.随着无线通信宽带化技术的突破, The l G analog system corresponds to Frequency Division 移动通信正在向以CDMA为基础,以宽带 Multiple Access technology(FDMA),which provides a band— 化通信为特征的第三代(3G)技术发展。本 width of 9.6kbit/s The typical I G systems include AMPS in 文介绍了移动通信相关的技术,并探讨了这 US.NMT in Nordic countries and TACS in the UK The 2G 些技术的发展。 digital system mainly refers to the Time Divi sion Multiple 2 GSM茸CDMA Acce ss(TDMA)and the Code Divi sion Multiple Acce ss 第  ̄CDMA),both of which provides a transmission rate of 9 6 28. 址',VDMA)技术,它仅能提供9.6 kbit/s通 8kbids.Typical 2G systems include GSM in Europe.the digi— 售速率。其典型系统,如美国的先进模拟电 tally enhanced IS—l 36 in North America,CDMAOne IS.95A. 维普资讯 http://www.cqvip.com

IS一95B and PDC in Japan Compared to IG.the 2G system is stronger in privacy protection spectrum efficiency,applica— 话系统(AMP8)、北欧的移动电话(NMT) 系统、英国的全接^通信系统(TACS)等。 tion S and standardization Both 1G and 2G are designed to meet voice communications needs,which will remain the cor— nerstone and mainstay busines S at present and in the near future.and digital voice communications will keep its preva— lent position in the mobile market.This is especially true for 第二代窄带数字系统的接八技术主要有时分 多址(TDMA)技术和码分多址(CDMA) 技术两种.它可以提供9 6~28 8 kb-t/S 的传输速率。真典型系统,如欧洲的全球移 动通信系统GSM、北美的数字增强型系统 jS一136、odma Otie、iS一95A、IS 95B、 developing countries,where people’S demand for communica— tions iS still focused on voice.So jn the next few years.2G will remain a pillar business in the mobile market in suchlike conntries 日本的个人数字蜂窝(PDC)系统等。与第 一代模 蜂窝移动通信相比,第二代移动通 信系统具有保密性强 频谱利用率高、能提 供丰富的业务 标准化程度高等特点。无论 是第一代还是第二代,主要是针对话音通信 设计的,它仍是当前和未来一段时间内移动 通信市场的基石和圭阵地 数字话音移动通 信仍是移动通信的兰流市场 特 对发展中 国家而言,人们对通信的需求还主要集中在 话音领域,所以,在未来几年中,第二代势 字话音通信仍然是这些匡家移动通信南场的 重点和支柱。 3移动智能网技术 殪着移动逢信的发展,运营商和用户对 业务拓展的需求不断增强,从通信技术发展 的角度看,未来的通信网络必将是个宽带 化、智能化、个-畦化的网络 作为第二代移 动暹信技术的GSM和CDMA系统,网结体 系结构逐步由移动网向智能化方向发展.在 移动网络中引^智能网概念.增加智能网相 3 关功能模块.使得玛动网络能够很容易地提 供更多新业务来进步满足客户不断增长 expectation of operators and users to expand the range of services.In a development perspective the communications network in the future will surely be a broadband,intelligent 变化的需求 对应于GSM和CDMA两种移 动网络的智能网功能模块分别是移动智能网 ——移动网增强逻辑的客户化应用 and personalized one.So the network architecture of 2G GSM and CDMA systems will gradually evolve to an intelligent one. and the IN concept is to be introduced into the mobile network By adding IN—related functional modules the mobile network wil I be empowered to provide more new services in an easy manher SO as to meet the ever—increasing and changing user (CAMEL Customised A0DjIcat10ns for Mobile Network Enhanced Logic)祀无线智能网(WIIX,WirelesS Intelligent Networ,<)。北美CDMA移 动通信系统采用的是ANSI一/-1 D切I议.为 了支持智能业务.在ANS 41 D协议的信专 结构和信令流程的基础上又定义了一系列无 l 35 1薰 维普资讯 http://www.cqvip.com

技口圈固 II demands.The IN functional modules corresponding to GSM and CDMA networks are CAMEL(Customized Applications for Mobile Network Enhanced Logic)and WIN(Wireless In— telligent Network)respectively.It is worth noting that the CDMA system in North America is applied the ANSI一41D protoco1.In order to support intelligent services,a series of WIN protocols are defined based on the signaling structure and serviceflow oftheANSI41D protocol,includingIS一771 1S一 826 and IS一848 All those protocol s will be ultimately into— grated into the ANSI・4IE protocol,which is to be an all~IN・ based core network protoco1 While CDMA wireless IN is in progress in North America,the ETSI is driving the application of intelligence on the GSM network by working Out mobile IN protocol series to provide CAMEL service for GSM users. 线智能网(WIN)协议,分别是IS 771、IS一 CAMEL adopts the IN service control function and provides a 826和IS一848,这些协i议最终将整合到 mechanism to enable the GSM network to orfcr services inde— ANSI一41 E协议中,M而使ANSI-41 E成 pendent of the service network. Intelligence,personalizatiOn 为一个完全基于智能网的核心网络协议 在 and broadband represent an irreversible trend of future 北美C ̄MA无线智能网发展的同日 ,ETSI communications.This wiI1 surelY serve to speed up the per— 也在推动着GSM移动网络智能化的发展, fection and development of the mobile IN technology 研究和制定了为G S M移动用户提供 4 GPRS vs.cdma 2000Ix cAM E L业务的移动智能网系列协议。 With the explosive growth of Internet in the world,the CAMEL是一种业务,它采用智能嘲业务控 mobile data service is on rise in usage.That is why we are 制功能,提供一种机制,使GSM网络能够 convinced that in the mobile world data Iraffic wil1 at last ex— 提供独立于服务网络的业务 智能化、个性 teed voice one However,to build the 3G system that is tar・ 化、宽带化则是整个通信发展的必然方向, geted at future multimedia communications,there is still a long 这必将推动移动智能网技术不断完善与发 way to go.So how to make use of the existing 2G system to 展 transmit data is a necessary task for us to fill in the market 4 GPRS皇odrna 200O 1x gap.Analysts believe that mOSt of the 3G features can be neatly 髓着全球范围的Internet用户数爆炸 realized via the current 2G technology,especially given that 式的增长,目前移动数据业务的上升势头也 the demand for mobile data communications is a by—product 非常迅猛,这使得我们充分相信,在移动通 of the soaring growth of mobile communications and the 信中,数据通信量也将在某一天超过话音通 Internet.There are two approaches for that purpose.One is to 信 但要完成专门针对未采多媒体通信的第 add data transport capability in the voice—dominant cellular 三代系统建设还需日 日,所以如何利用现有 mobile communications system;the other is to combine mo— 的第二代数字系统实现数据通信,是填补南 bile communications with the Internet By doing so a number 场需求空间白与必然选择:分析家们认为,实 of technologies were produced,e g.,the General Packet Radio 际3G技术所具备的功能绝大部分其实完全 Service(GPRS),the Enhanced Data Rate for GSM Evolution 就可以在目前第二代无线技术的基础上实 (EDGE),the IS一95B agg regation techn0logY.th e 现,特别是随着移动通信和因特网服务快速 CDMA2000 1 x technology,the Wireless Application Protocol 维普资讯 http://www.cqvip.com

(WAP},BIHetooth and so on.Among them,GPRS and CDMA2000 I x especially GPRS(a GSM—based packet switch— 发展而随之产生的移动数据通信要求。其方 法有两种 是在以电话为主的蜂窝移动通 信系统中增加传送数据的能力二是移动通 信与园特网的结合 由此产生了几种相关技 术,如通用分组无线服务(G。JRS)技术;增 强数据速率魂进(EDGE)技术:IS 95B利 用码聚集技术:ccma 2000 1×美术、无 线应用协议WAP扳犬:蓝牙(Bluetoozh) ing technology).are attracting much attention and of special practical significance to China GPRS i s launched to cater to the soaring growth and in— creasing integration of GSM and the global lnternet market It provides GSM operators an important platform for them to expand service portfolio from solely voice to integrated infor— motion services,thus laying a foundation for the GSM transi— lion to 3G In that sense it is dubbed as“the propeller of fu— 技术等 其中,G'-'PRS和cdma 2000 1 x, 特别是GPRS作为基于GSM 分组交换蕴 术,格外引人注目,对我国来说也具有特别 重要的现实意义。 lure 3G market”.GPRS i s characterized by the following:a) it provides end—-to—end packet data transmission from wireless part to wireline part.On the wireless part.voice and packet channels can be allocated on demand in an dynamic way to GPRS是迎合GSVI移动通信市场和全 球园特网的迅猛发展和日益融合而推出的, 它为GSM运营商由仅提供话音业务拓展到 舞合信息服务业务领域提供了重要 网绍平 台,并为GSM向第三代移动通信的过渡打 下基础,被 为 未来3G市场的助推器” 它有如下特点 是M无线部分到有线部分 提供端到端的分组数据传输,无线部分可按 需动态分配话音和分组信遒,更为有效地利 make an effective use of the frequency resource;b)it provides higher access rate for risers【1 1 5kbit/s)and less access time; c)it provides SMS,WAP and existing data services in a more effective manner;d)its bottom layer is based on TCP/IP,mak— ing it able to be seamlessly connected to the Internet:e、it sup— ports billing according to time of usage and traffic;f)With the wide GSM coverage,it provides anytime anywhere data access; g)by taking GPRS it is not necessary to incu r major changes to the GSM equipment.Most of the experts believe that GPRS is a 2.5G system that stands between GSM and 3G In the w a k e of 用频率资澡二是旬用户提1共更高 接^速 率(11 5 kbit/S)和更短的接八时司:三是 可更为有效地提供短消息、'WAP等原有数 据业务 四是 毒层基于TCP GPRS andif GSM opera— tors have no P,可与因特 网进行无缝连 接:五是可提 3 G s P e ct rnm, t h e y c a n make use of 供按时司、流 量、内容等更 加灵活的计费 方式;六是依 靠GSM的广阔 覆盖,可提供 随时辐地的数 据接^:七是 对原有GSM EDGE t o bring upthe rate to above 3 8 4 k bit/s that i s qnite clo se to the 1e v el of 3G s y st em. If 备无需进行大 的改动。专家 维普资讯 http://www.cqvip.com

拄凹啕囝 _I l 萋≥ 率提到2,84 Knit s 接近第三代移动通信 系统朗水平 如果运营商拥有第三代的频 谱,则可以M GPRS直接过渡到第三代。 与GPRS 乍为GSM向第三代过渡的作 用相似,sdma 2000 1×则是窄带s一95系 统向第三代系统平滑过渡的标准,它可以提 供144 kbit/S速率以上 数据业务,而且 增加了辅助信道等,可以对一个用户同时霞 载多个势据流和多种业务,为支持未采的多 媒体分组业务打下了基础 5 3G operators have 3G spectrum by then,they can directly trans一 1ate GPRS into 3G. Similar to GPRS as a stopgap means,CDMA2000 1 x is a standard for the narrowband IS一95 system to evolve to 3G It provides data rates of up to 144kbit/s and introduces support— ire channels thus able to carry multiple data traffic and ser— vices for one single user This has laid a good foundation for supporting various muItimedia packet services in the future 5 3G In the past years.the 3G system has been mainly driven by three factors.Firstly,very few 2G spectrum is left for u se— actually not more than l 00MHz,and the spectrum effici ency is not satisfactory.In addition,with the non—stop launching of new data services,the capacity in hot areas of cities el?court— tries is yet to be sufficient In comparison.the 3G system needs 近些年来,第三代技术的发展动力主要 夹自三个方面一是原有第二代系统使用的 only a bit more than 230MHz with a high spectrum efficiency, a wide coverage and better performance thus able to soIve the 颤率资源较少,不到10O ^Hz,且其频谱利 用率相对较低,加上新的数据业务的不断推 出,使得目前在一些国家和城市的中心地带 Cllrrellt service deployment bottleneck SecondIy.with the 容量严重不足而第三代移动通信系统的频 谱资源至少在230 MHz以上,且频谱利用 率较高.覆盖范围更厂,性能更好,M而可 以很好地解决现有业务的开展闻题。二是随 着社会信息化进程的加快,人们对碜动数据 业务的需求越来越高,尽管目前第二代系统 也可以开展些数据业务,但由于受带宽的 限制,无法道应开展诸如Internet、电子商 务 高速数据 活动视像和VOD等数据多 媒体业务的需要而第三代系统可以针观不 同的业务应用.提供M 9.6 kbit/s直至 2 Mbit/s的接八速率,从而很好地满足这 需要 三是全球体化的进程迫切需要一 of 3G standards,i e..the US.advocated CDMA2000the .个全球坑一的移动通信设备,以实现全球漫 游的需要.但蓠二代移动通信系统的多制式 眈空中接口和网络设备,难以实现这个要 WCDMA proposed by Europe and Japan and the TD—SCDMA from China,which are all featured by high spectrum effic ency, 求,医此新的有望实现全球统一的移动通信 纛统被寄予厚望 目前,国际电联接受的第三代移动通信 系统标准主要有三个,即美国提出的cdma wide coverage,sati sfactory performance and adaptability to broadband OIUltimedia corumnn[eations On tOD of thatthe .standards a1 so have their owu technica1 characterlstics The core network of WCDMA is based on GSM—MAP ■■ 维普资讯 http://www.cqvip.com

2000,欧洲和日本提 的WCDMA和我国 提出的一 一SCDMA:它们桀了频谱利用 率高、覆盖范匿广、性能好、可以适应宽帝 多媒体通1言要求等共同特点外,还有自宴啦 技术特斋: WODMA系统的核心网是基于cS M A P,同时逢过网络扩展方式提供基于 ANS r一‘1的核心网上运行 能力,可以M :&  群i n one ce il. : MA ,第二代GSM系统逐步演进:支持墨连线 上传输多条并 业务 支持高速率的分组接 八;采用更趣灵活的系统操作,包括支持基 站司的异步操作,支持自适应天线阵技术与 多用户检测的技术,支持非 衡频带下采用 时分双工的模式,采用荜信元频率复用等 itis cap able。,: Cdma 2000的核心网是基于ANsl_ 41,采用直接扩频码分多址技术的无线接 口,符合甚至超逛了ITU的全部规范要求 具备先进的媒体接八控制,M而有效地支持 The system can also well handle the ompeting services.It can flexibly se・ nd data modes according to environ・ and support both distributed and cen- ices.It can also choose to adopt inde— 高速分组数据业务具有先进啦多媒体业务 质量控制能了],支持不同业务相应不同质量 要求的控制,处理竞争业务间的优先权问题 等;可 根据环境和需要灵活地选择语音、 and signaling for voice transmission and support FDD duplex and TDD duplex Besides that.the system supports forward multi-carrier structure and orthogo-— nal direct spectrum spreading with flexibility and scalability 语音/数据和数据模式 支持分布式和集中 式的分组数据业务.可选择采用独立 分组 控制与信专传送话琶支持频分双工 =DD) 和日口分双工( Dljj支持前向多载波结构和 and the evolution from CDMAOne is no difficult.It can also employ technologies such as auxiliary pilot.orthogonal diver- sity and multi—carrier diversity to improve the syStern performance 正交直接扩频。具有较好的灵活性与可伸缩 性,可非常容易地M现有的cdm8 One平 滑过渡,还可采用辅助导频、正交分集 多 载波分集等菝术来提高系统的性能。 T]一SCDMA基于G8M系坑,采用智 Based on GSM,TD-SCDMA adopts the intelligent antenna and low code rate technology to achieve a high spectrum efficiency,thus making it good at easing the short supply of frequency resources in densely populated areas Also,the sys— tem exhibits an eminent advantage in asymmetric mobile data 能天线和低码速垂技术,频谱利用率很高, 能够解决人口密度地区频率资源紧张的同 题,井在互鞋网浏览等非对都移动数据和视 频点播等多媒体业务方面具有突出优势 系 统的基站天线是个智能化的天线阵.能孵 transmission like the Internet surfing and multimedia services such as V0D.The base station antenna consists of an inte]li gent array.which can automatically decide and track the Inca don of the handset and ensure that the transmission beam is pointed to the direction where the handset heads,thus brin g 自动确定井跟踪手机 方位.发射渡束始终 对硅手机方向,可降低基站的发射功率。上 行同步ODMA技术可便上行信号与基站解 ing down the transmission power of base stations The uplink 调器完全同步,降低了码间 干扰、使硬件 维普资讯 http://www.cqvip.com

技强圈囝 _ __  碍到茸化.成本降低。T[ signal can synchronize with the base station demodulator,thus 采用软件无线电技犬,使运 reducing the interference between code heads,simplifying the 季 … 1/4- “L hardware structure and cutting back on the COSt Also,TD— 信号.通迂加载不同的辆件就可实现不同的 SCDMA is equipped with the software radio technology When 业务。同时,系统基站采用高集成度、低成 operators plan to add new services,the software on the same 本设计。此外,TD—SODMA系统可与第 hardware platform can be used to process the baseband signal 二代移动通售系统GSM兼容。 Meanwhile,diferent services can be realized by loading dif— 由此可见,经过多年的研究,第三代系 ferent sorts of software Plus,the base station in the system 统的研究特勋是前两个目标的达成方面业已 leverages a highly integrated and cost・effective design Last 取得了重大的进展,但是从总体上来说,第 but not least,the TD—SCDMA system is compatible with GSM. 三代系统目前还主要处于试验阶段,个别系 After years of research work on 3G,especially taking into 统则刚刚开始试商用阶段。 account the first two objectives,we must say that substantial 3G标准的一个重要特点就是强调演化 progress has been made.Whereas,generally speaking,the 3G 为了保证移动运营商的利益,源于欧洲的 system is still in the stage experiments.Only a few individual GSM 是M二代的窄带话音,演化到数据 systems have been commercialized thus far 通信.就是现在正在推厂的2 5代GP ̄S; One of the important features of the 3G standard i s an em— 再演化虱宽带数据通信 在这一演化过程中 phasi s on evolution.To ensure operator benefits,the Europe— 电信技术在飞速进步 5年前几乎所有甑书 origihated GSM system started by the narrowband 2G voice 一讲宽带就是宽帝ISDN,基于ATM协议, service.then evolved to data communications,namely,the 2. 现在的宽带网已经是全IP协议了.而3G还 5G GPRS service currently being deployed The next stage 是基于ATM协议,走的路线不对。所以,欧 wiII be broadband data communication s In thi s evo1ution 洲3G WCDMA的标准化组织3GPP又制 process.the telecommunications technology is growing at a 订进一步的演化标准.向全P网演化 现在 fast pace.Five years ago.nearly alI textbooks classified broad. 的标准是Release 99(1 999年版).不基 band into ATM.based ISDN.However,nowadays the broad. 于IP协议;演化到Release 2000(2000 band network is already closely'linked to an al1-IP protoco1. 年版);看来发现Release 2000太复杂,又 Whereas.3G is still A TM・based,that i s why people thought 分两步走,先是Release4(版本4),再到 they were on the wrong path and the European 3G—WCDMA Release5(版本5),然后再往下走,才能 standardization organization 3GPP tried to work out further 演化为全IP网。这洋的标准演化过程,可能 standards for evolution to an all—IP network.The standard 需要3~5年时间。由于标准制订有问题.电 currently in force is Release 99(the 1 999 version).which is 信运营商对于把3G移动通信投八商业化运 not based on IP Then there was Release 2000 f山e 2000 营都很谨慎 即使3G的上述技术问题获得 version).Later.Release 2000 was found to be too complex 解决,在普及应用方面也还存在一些必须逾 So tWO further step s were made:first Release 4(version 4j 越的障碍 一是消费者使用手机的最主要目 and then Release 5(version 5)before going all the way up to 的是通话方便,尽管3G系统能提1共各种业 an all・IP network.Such a standardization process probably 务能力,1旦消费者对这些业务的需求程度、 wiIl take 3 to 5 years of time.Due to thi s.telecos are now 兴趣和习惯如何还是一个很大的未知数二 prudent in commercializing 3G Even if the abo, ̄e technical 是3G系统投资非常巨大,这些投资必然转 problems concerning 3G is resolred.there are still some un— 加到消费者的服务收费上,再力r上集众多功 avoidable obstacles in the way of spreading 3G applications. 能于一宴 3G手机价格不会便宜,因而能 Firstly,users are dealing with cellphones for the purpose of 维普资讯 http://www.cqvip.com

convenience in commonications.Although 3G may provide a wide arrav of service capabilities.it iS stilI yet to be known to what extent users may really need them.Secondly,3G system 否被消费者接受也是一个未知数三是虽然 M理论上说,3 G手机的传输速度能达到 384 kbit/s或更高,但手机的速度将受到 通信系统容量的限制,如系统容量有限,手 机用户越多,速度就越幔 据有关专家分 析,3G手机将很难达到其理论速度 因此, 据估计,3G系统估计仍要2~3年的日 司才 requires hefty investments.which will then be bu rdened on uggrs in the form of service charges.In addition it is quite possible that the functionally rich 3G handsets won t be sold cheaply So whether or not users is willing to accept the hand— set model remains a question.Thirdly,3G handsets may reach a transmission rate of up to 384kbiffs or even higher,but the 能推出成熟的商用系统。第三代移动通信有 如下关键技术: 是高效信道编译码援犬; 二是智能天线技术;三是初始同步与Rake handset speed is SUbject to system capacity limitations.With a limited system capacity,the more users the slower the rate. Experts estimate that it would be very difficult for 3G hand. sets to get to the theoretical speed.Therefore,it will take 2 to 多径分集接收技术:四是多用户检测技术: 五是功率控制技术 第三代碣动通信系统的 出现将使人类的通信方式出现革命性的改 变,在任何地方以任何方式进行通信将成为 珊实。 3 years of time for 3G to become a mature commercial system. Given all that,the 3G system nevertheless has demonstrated 表1 年代 系统 技术 壤拟 数字 业务 20世纪8O年代 1G 2O世纪9o年代 2G 2000年 3G 模拟蜂窝电话、模拟无绳电话 数宇蜂窝:G IS一54 PDc 数字无绳 DECT PHs移动卫星 全球标准 lMT一2OO0(3G蜂窝1最大数据率.2mbit/s 2010主 e 高教据率.商机动性.基于. 簟 霪 量 嚣 . 5G 高散据辜,商机动性.基于fP 磊墓 ; HAPS最低数据辜:2~20Mbit/s 2020年 the following key features:highly efficient channel coding/ decoding;smart antenna;initial synchr0nization and Rake multi。path diversity reception;multi—user detection and power contro1.All in all,the emergence of 3G system will funda— 6 4G 未来几代移动通信系统最明显的趋势是 要求高数据速率、高机动-l生和无缝隙漫游 实现这些要求在菠术上将面临更大挑战。此 外.系统性能(如蜂窝规模和传输速率)在很 大程度上将取决于频率的高低。有人认为, 4G技术指标.应用范围各方面如果没有“革 mentally change OU r way of communications,thus turning the anytime anywhere communications into a reality 6 4G The most noted trend of future generations of mobile corn— munications system is the requirement for high data speed, 命性”的变革,不能够叫“aG”。4G移动通 信的数据传输应该比3G高个数量级4G 应该包含以下4个主要特点:一是自适应的 资源分配,能够处理变化的业务流、信道条 high flexibility and seamless roamingTo that end、there will .be even greater technical challenges looming aheadBeside s, .维普资讯 http://www.cqvip.com

lll技衄咽固  件_/、司蓝环境,有很强的自组织吐和灵若 一。皇二是能综合固定玛琵广播网络或其他的 the system performance(e g,cell size and transmission rate) is to a great extent dependent on frequencies Some people 些规 一.实现对这些功能体袄分布 控 制三是这个协议应谚能根据网络的动态和 自行变化 信道条件.使低码与高码的用户 能蜗共存 这些方面都要比2G、3G先进; 四是主要发展数字广带(Broad band)为 基础的概念 在”毫米 过程中,传播条件 相对困难.蜂窝小区也会相应小很多,这会 引起系列技术上的难题。相比4G、5G移 tend to think that since there is no’ revolutionary’’changes taking place in technical indicators and application s,there should not be a term of“4G”in place.So the data rate of the 4G System should be at 1ea st one order of magnitude above that of 3G.and 4G should include the followjng four main features Firstly,it should enable adaptive resource alloca— tion to handle changing traffic and channel conditions with a strong self—organization capability and flexibility.Secondly, it shou1d be ab1e to combine the rules of fixed mobi1e broad— cast network or other networks to exert a controI over the vo]一 通信系统也将在未采实现。表1为移动通 信系统的发展历程(4G、5G系统的年代为 粗略估计)。 ume distribution of those features.Thirdly',the protocol should enab1e the co—existence of both 1ow and high code users ac— cording to network dynamics and changing channel conditions 7结束语 随着新世纪的到来和中国加八wT0, 中国移动通信产业将面临更大的发展机遇和 更强有力的挑战 分析了解玛动通信技天的 In those'respects,4G should demonstrate a performance supe— riot than 2G and 3G.Fourthly',the Digital Broadband concept 发展,有刊于我们总结经验,把握方向,抓 住机遇,早日建成满足未采业务需求的移动 通信网。t should be incorporated In the”millimeter”process.the propa— gation condition is relatively difficult.C。rrespondingly the cell size will be much smaller,thus bringing about a series of technical headaches.Compared to 4G.the 5G system will also 作者简介: 张光海 1 9 91年哈尔滨工业大学获得工学 come into reality in the future Table 1 shows the develop— ment of mobile communication s(the deployment time of 4G and 5G systems are rough estimatesj 硕士学住,:9 98年在华南理工大学获得工 学博士学位,2 o oo年从清华大学博士后出 站,现在中国移动通信集团 司工作。 收稿日期:2002—02一I6 7 Conclusion The advent of a new century and China’s entry to the WT0 brought along both opportunities and challenges to China’s mobile communications industry.Therefore,an in—depth anal ̄,一 sis of the development of mobile cornmunication s systems is 参考文献 [1]朱建华.移动通信技术的发展、回 望和展望.邮电科学,2000(1):21~25 helpful for us to sum up experiences,head in the right di rec— tion and get hold of opportunities to accomplish the building of a mobi1e communications network that js tailored to future user needs [2]是晓文,赵建平.移动通信的发展 与展望.邮电科学,2O01(8):8、1 5 Biography: Mr Zhang Guangh ai graduated from Harbin Industri a [5]陈小敏.通用无线分组业务综述. 现代通信技术,2001(4):1 1~1 5 University in 1991 and got hi s Ph D at South China Techno logical University in 1998 In 2000,he aecompolished his post doctorate research in Tsinghua University He is now work l4]5GPP.http://www.5gpp.org ing for China Mobile Communication Corperation 

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