unit 9GSM (Global System for Mobile Communication)
unit 9 GSM (Global System for Mobile Communication)
The success of mobile systems across the world is a signthat communication is moving towards a more personalizedconvenient system.personalize［‘p：snlaiz］v.使个人化convenient［kn‘vi:njnt］a.便利的，方便的People who have to use a mobile phone on business soonbegin to realize that the ability to phone any time, anyplace in one's personal life rapidly becomes a necessitynot a convenience.[ni5sesitin.必要性，需要，必需品necessity[kEn5vi:njEns]n.便利，方便，有益，有用的，方convenience的用具、机械、安排等
The success of mobile systems across the world is a sign that communication is moving towards a more personalized, convenient system. personalize [‘p :s n laiz] v.使个人化 convenient [k n‘vi:nj nt] a.便利的，方便的 People who have to use a mobile phone on business soon begin to realize that the ability to phone any time, any place in one's personal life rapidly becomes a necessity, not a convenience. necessity [ni5sesiti] n.必要性, 需要,必需品 convenience [kEn5vi:njEns]n.便利, 方便, 有益, 有用的,方便 的用具、机械、安排等
The speed and rapidity with which the personalcommunications revolution takes place is, unlike fixedtransmission systems, highly dependent on technology andcommunication standards.rapidity［rE5piditi]n.速度，迅速，急速revolution[7revE5lu:FEn]n.革命，旋转For mobile the three key elements to achieving servicetake-up are the cost, the size and the weight of thephone, and the cost and quality of the link.接受，领take-up[5teik5Qp]］n.拉紧，紧线器，拿起，举起；取崛起腾飞
The speed and rapidity with which the personal communications revolution takes place is, unlike fixed transmission systems, highly dependent on technology and communication standards. rapidity [rE5piditi] n.速度, 迅速, 急速 revolution [7revE5lu:FEn] n. 革命, 旋转 For mobile the three key elements to achieving service take-up are the cost, the size and the weight of the phone, and the cost and quality of the link. take-up [5teik5Qp] n.拉紧, 紧线器, 拿起, 举起; 接受, 领 取 崛起 腾飞
If any of these are wrong, especially the first two, thenmarket growth is liable to be severely restricted.1iable [5lalEb(E)I] adj.1（常与to连用）易于的，有倾向的2（常与for连用）负有责任的，负责的3将受到法律制裁的severely[si5viEli]adv.严格地，激烈地，严重地[ris5trikt] vt. 限制,，约束，限定restrict?
If any of these are wrong, especially the first two, then market growth is liable to be severely restricted. liable [5laIEb(E)l] adj. 1（常与to连用）易于.的，有.倾向的 2（常与for连用）负有责任的，负责的 3 将受到法律制裁的 severely [si5viEli] adv. 严格地, 激烈地,严重地 restrict [ris5trikt] vt. 限制, 约束, 限定
The fixed telephone service is global and theinterconnection varies from coaxial cable to optical fibreand satellite.The national standards are different, but with commoninterfaces and interface conversion, interconnection cantake place.vary[5vzEri]vt．改变，变更，使多样化vi.变化，不同，违反coaxial［kEu5AksE]adj.同轴的，共轴的axial [5AksiEl] adj轴的，轴向的conversion[kEn5vE:FEn］n.变换，转化convertv.conversation［7kCnvE5seiFEn]n.会话，交谈conversekEn5vE:s]vi.谈话，交谈，认识n。相反的事物，倒，逆行adj.相反的，颠倒的
The fixed telephone service is global and the interconnection varies from coaxial cable to optical fibre and satellite. The national standards are different, but with common interfaces and interface conversion, interconnection can take place. vary [5vZEri] vt. 改变, 变更, 使多样化vi.变化, 不同, 违反 coaxial [kEu5AksEl] adj. 同轴的, 共轴的 axial [5AksiEl] adj. 轴的, 轴向的 conversion [kEn5vE:FEn] n. 变换, 转化 convert v. conversation [7kCnvE5seiFEn] n.会话, 交谈 converse[kEn5vE:s] vi.谈话, 交谈, 认识 | n.相反的事物, 倒, 逆行adj.相反的, 颠倒的
For mobile the problem is far more complex, with theneed to roam creating a need for complex networks and很，极，太faradv.远；远隔；[rEum］v．漫游，闲逛，倘祥n.漫步，漫游，roamThus in mobile the question of standards is far morecrucial to success than fixed systems.In addition, there is also the vexed question of spectrumallocation in the mobile area.crucial[5kru:F(E)adj.极重要的：有决定性的vex[veks］vt.烦恼恼火；恼怒in addition adv. 另外 Also; as well as.in addition to adv.除...之外还Over and above; besides
For mobile the problem is far more complex, with the need to roam creating a need for complex networks and systems. far adv. 远；远隔; 很，极，太 roam [rEum] v. 漫游, 闲逛, 徜徉n.漫步, 漫游, 徘徊 Thus in mobile the question of standards is far more crucial to success than fixed systems. In addition, there is also the vexed question of spectrum allocation in the mobile area. crucial [5kru:F(E)l] adj. 极重要的；有决定性的 vex [veks] vt. 烦恼；恼火；恼怒 in addition adv. 另外 Also; as well as. in addition to adv. 除.之外还 Over and above; besides
Mobile systems originally operated in analog mode in the450 MHz band, moving later to 900 MHz with digital GSM andthen to 1 8oo MHz with personal communication systems.The history of mobility can split into generations.mobility［mEu5bilitiln活动性，灵活性，迁移率，机动性The first generation systems were the advanced mobilephone systems (AMPS) in the U. S. , total accesscommunication system (TACS) in most of Europe and Nordicmobile telephone system (NMT); which were all analogueNordic5nC:dikln.北欧人，日耳曼民族，具有北欧日尔曼民族外貌特征的人adj.北欧人的，日耳曼民族的
Mobile systems originally operated in analog mode in the 450 MHz band, moving later to 900 MHz with digital GSM and then to 1 800 MHz with personal communication systems. The history of mobility can split into generations. mobility [mEu5biliti] n活动性, 灵活性, 迁移率, 机动性 The first generation systems were the advanced mobile phone systems (AMPS) in the U. S. , total access communication system (TACS) in most of Europe and Nordic mobile telephone system (NMT); which were all analogue systems. Nordic[5nC:dik]n. 北欧人, 日耳曼民族, 具有北欧日尔曼民族外貌特征的人 adj.北欧人的, 日耳曼民族的
The second generation is much dominated by the standardfirst set out in Europe by the group special mobile (GSM)committee, which was designed as a global mobilecommunication system.dominate[5dCmineit］v.支配，决定，占优势V.出发，开始，装饰，陈列，测定，宣布，移植，陈述set out；启程；展示制定The GSM system is based on a cellular communicationsprinciple which was first proposed as a concept in the1940s by Bell System engineers in the U. S.[prE5pEuz]proposevt．计划，建议，提出，向..提议，求(婚)vi.打算，求婚
The second generation is much dominated by the standard first set out in Europe by the group special mobile (GSM) committee, which was designed as a global mobile communication system. dominate [5dCmineit] v.支配,决定, 占优势 set out v.出发, 开始, 装饰, 陈列, 测定, 宣布, 移植, 陈述 ; 启程; 展示 制定 The GSM system is based on a cellular communications principle which was first proposed as a concept in the 1940s by Bell System engineers in the U. S. . propose [prE5pEuz] vt. 计划, 建议, 提出, 向.提议, 求(婚) vi. 打算, 求婚
The idea came out of the need to increase network capacityand got round the fact that broadcast mobile networks,operating in densely populated areas, could be jammed by avery small number of simultaneous calls.The power of the cellular system was that it allowedfrequency reuse.come out ofv.由...产生；从...出来V．避免，说服，走动，传开来get rounddense[dens]adj.密集的，浓厚的denselyadv.[dVAm]］n.果酱，拥挤，堵塞，困境jamvt．挤进，使塞满，混杂，压碎，使堵塞vi.堵塞，轧住，拥挤
The idea came out of the need to increase network capacity and got round the fact that broadcast mobile networks, operating in densely populated areas, could be jammed by a very small number of simultaneous calls. The power of the cellular system was that it allowed frequency reuse. come out of v. 由.产生 ；从.出来 get round v. 避免, 说服, 走动, 传开来 dense [dens] adj. 密集的, 浓厚的densely adv. jam [dVAm] n.果酱, 拥挤, 堵塞, 困境 vt. 挤进, 使塞满, 混杂, 压碎, 使堵塞 vi.堵塞, 轧住, 拥挤
The cellular concept is defined by two features, frequencyreuse and cell splitting.Frequency reuse comes into play by using radio channels onthe same frequency in coverage areas that are far enoughapart not to cause co-channel interference.come intoplayv.开始活动，起作用co-channel共信道interference[7intE5fiErEns]n.冲突，干涉This allows handling of simultaneous calls that exceed thetheoretical spectral capacity.handle[5hAndl]n.柄，把手，把柄，口实，手感；【计]句柄vt.触摸，运用，买卖，处理，操作vi.搬运，易于操adj.光谱的，鬼怪的[5spektrEl]spectral
The cellular concept is defined by two features, frequency reuse and cell splitting. Frequency reuse comes into play by using radio channels on the same frequency in coverage areas that are far enough apart not to cause co-channel interference. come into play v.开始活动，起作用 co-channel 共信道 interference [7intE5fiErEns] n. 冲突, 干涉 This allows handling of simultaneous calls that exceed the theoretical spectral capacity. handle [5hAndl] n.柄, 把手, 把柄, 口实, 手感；[计]句柄 vt.触摸, 运用, 买卖, 处理, 操作 vi.搬运, 易于操 spectral [5spektrEl] adj. 光谱的, 鬼怪的