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