The development of telecommunications

1、The development of telecommunications3 stagesPrimary communication stage 1838 telegraph cable(Morse) 1843 teleprinter patent(Alexander Ben) 1864 the theory of electromagnetic radiation(Maxwell) 1876 telephone(Bell) 1880 the first pay phone system 1896 wireless telegraphy (Marconi) 1920 broadcasting(

2、BBC)Modern communication stage(1948 Shannoninformation theory ) 1951 direct dial opened 1956 overseas communication cable laid 1957 the first man-made earth satellite launched 1958 the first communications satellite launched 1960s computer network began to appear 1969 television and telephone servic

3、e opened 1970s Commercial satellite communications, program-controlled digital switches, optical fiber communication system put into use Modern communication stage (1980s) 1980s digital network developed(PC&LAN) 1990s Optical fiber communication has been widely used Internet developed rapidly an

4、d vastly PRIMARY COMMUNICATION STAGETHE MORSE CODE摩尔斯电码 As we all know that in 1838,an American, Samuel Finley Breese Morse invented the Morse code.It is a communication mode which only use dot and dash with different order. Morse code is widely used in war to pass on the message secretly. It helps

5、soldiers to defeat the enemy effectively.THE TELEPHONE In 1876, Alexander Graham Bell invented the telephone .This is the invention of the revolution and until today,we still use phone everyday.This invention helps people talk to each others conveniently.And we no longer need to write letters to the

6、 one who we miss or want to talk to but live far away from us.THE WIRELESS TELEGRAPHY无线电报 In 1896,a man invented the wireless telegraphy.Hes name is Guglielmo Marchese Marconi,an Italian. And his invention is used in military,transportation,rescue,astronomy,animal protection and so on.Today many peo

7、ple call themselves “radio amateur”,they all love to study the application of wireless telegraphy.The influence ofmodern communicationSatellite Communications Fiber OpticalCommunicationMobileCommunicationmodern communicationDataCommunication中国特色的QPS系统北斗卫星日本推出“视像眼镜” 在眼镜上看电影东方红卫星宁波推出车载卫星通讯系统宁波推出车载卫星通讯

8、系统 Optical fiber communication application field is very wide, it is mainly used for local trunk line（市话中继线）, optical fiber communication gradually replacing the cable.It is widely used，not only used for long-distance trunk communication ，but also used in high quality color television transmission,

9、industrial production field monitoring and scheduling， traffic monitoring control, cable networks in cities and towns, community antenna (CATV) system. 1、Mobile communication change the concept of people，and lead to the rise of the communication culture； 2、Information resources have the advantage of

10、 renewable so it can improve the efficiency of social and economic； 3、The mobile messages replace the greeting cards which will improve the environment and has benefit to environmental protection ；The ten major effect of the Internet 1、To shape a good image in the world, go the way of high-tech elec

11、tronic networks； 2、To help make friends ； 3、Offer more business information 4、To develop the international market, absorbing foreign technology and capital； 5、The direct sales of product； 6、Receive the voice of the customer ； 7、Offer 24h service； 8、Multimedia information transmission 9、Offer more new messages 10、Underspent a