新视野大学英语第四册第四单元.ppt

The Telecommunications Revolution Book 4, Unit 4 Proper names telecommunications optical fiber (L. 6) /high-capacity optical fiber links (L. 38) cable (L. 7) copper wire (L. 8) digital switches (L. 8)/digital model (L. 22)/digital mobile phone systems (L. 51) wireless transmission systems (L. 9) the Information Age (L.10) a spider’s web of digital and wireless communication links (L. 11) 电信 光纤. 光学纤维/高容量的光纤电缆网 电缆 铜线（电缆） 数字转换器/数字模式/数字移动电话系统 无线传播系统 信息时代 一个蜘蛛网般的数字和无线通信网络 Proper names the information superhighway (L. 39) log on (to)/ log out/off (L. 40) the electronic data (L. 42) /electron (L. 73) paperless trading (L. 43) radio tower (L. 53) string lines across mountain ridges (L. 53) wireless call (L. 55) fixed lines (L. 56) 信息高速公路 进入（计算机）系统；登录/退出 电子数据/电子（信号） 无纸化交易 无线电发射塔 翻山越岭架设线路 无线电话 固定线路 Telecommunications Telecommunications, from Greek, means “communications at a distance”. The first trend: the incredible increase in the processing power of digital computers, namely, dramatic decreases in physical size, dramatic increases in complexity, speed and capacity. The second trend: the explosive growth in transmission capacity through the widespread use of optical fiber across continents and under oceans. optical fiber Optical fiber (or “fiber optic”) often refers to the medium and the technology associated with the transmission of information as light pulses(光脉冲) along a glass or plastic wire or fiber. Optical fiber carries much more information than conventional copper wire and is in general not subject to electromagnetic电磁的 interference and the need to retransmit signals. Most telephone company long-distance lines are now of optical fiber. Information Age When we say that we live in the information age, we mean that?we live in a time when information is very important and easy to get. The information age is an era of fundamental and global change in intellectual, philosophical, cultural and social terms. Today’s information age began wi