电子信息工程专业英语教程第十课.pptVIP

《电子信息工程专业英语教程》 Unit 4 Electronic systems Lesson 10 The Mobile Telephone System (I) 《电子信息工程专业英语教程》任治刚 主编 电子工业出版社 Lesson 10 The Mobile Telephone System (I) Terminology cordless phone base station, mobile station　　 dial tone, dialing 　　　 antenna　 packet-switching MTSO, MSC, PSTN The History of Mobile Radio Communication Terminology 无绳电话 base station 基站 mobile station 移动站 A dial is… A graduated surface or face on which a measurement, such as speed, is indicated by a moving needle or pointer. 标度盘 The face of a clock. 钟表针盘 A sundial. 日晷 The panel or face on a radio or television receiver on which the frequencies or channels are indicated. 调谐度盘 A movable control knob or other device on a radio or television receiver used to change the frequency. 调谐钮 A rotatable disk on a telephone with numbers and letters, used to signal the number to which a call is made. 电话拨号盘 天线 A metallic apparatus for sending or receiving electromagnetic waves. also called aerial 包交换，分组交换 A packet is … A sequence of binary digits including data and call control signals that is switched as a composite whole. The data, call control signals, and possibly error control information, are arranged in a specific format. A short block of data of fixed length and destination information. It is the unit in which information (a message) is transferred in a packet-switching network. Packets may consist of as many as 8000 bits, and more from node to node in the network. MTSO: Mobile Telephone Switching Office 移动电话交换局 MSC: Mobile Switching Center 移动交换中心 PSTN: Public Switched Telephone Network 公共交换电话网 1880: Hertz – Initial demonstration of practical radio communication 1897: Marconi – Radio transmission to a tugboat over an 18 mi path 1921: Detroit Police Department: -- Police car radio dispatch (2 MHz frequency band) 1933: FCC (Federal Communications Commission) – Authorized four channels in the 30 to 40 MHz range 1938: FCC – Ruled for regular service 1946: Bell Telephone Laborat