Network Overview

One 、 What is network

So what we said “ The Internet ”, A general term for a telecommunications network 、 Cable network 、 Computer network these three networks . With the construction of triple play , And the development of computer network technology 、 Large scale construction of computer network infrastructure , Now? , What we say “ The Internet ”, More specifically, it refers to computer network .

Two 、 telecommunication network

Telecommunication network refers to the connected telephone 、 The telegraph 、 And fax service network , Telecommunication network is composed of telecommunication operators （ In our country , Now it is operated by three major operators , China Mobile 、 China Unicom 、 China Telecom ） The most common equipment that ordinary people touch is the telephone 、 SPC exchange 、 fax machine 、 Transmitter （ Equipment for generating electricity ） And telephone lines . As 80 The later generation , When Xiaobian was in middle school , Or did you send a telegram 、 Telegraphic transfer （ Send money through the telecommunications network of the post office ） Such a memorable thing . And our young 90 after 、00 Later, my friends only saw our underground party in the Anti Japanese drama 、 sound of dripping water 、 Use the telegraph to send messages ！！！！ Of course , As a military industry practitioner , I know that some military research institutes are still producing new radio stations , However, more data is transmitted through low-frequency wireless .

3、 ... and 、 Cable network

Cable TV network refers to the TV image transmission network in our home , Operated by China cable TV network corporation , Behind the scenes is “ The state administration of radio ”. In the past , If you want to watch TV at home CCTV And various satellite TV stations , You need to go to the radio and television business hall to open cable TV services , Of course , If you happen to have no cables laid in your home , I'm sorry , You can only be the same as when you were a child , Build your own antenna , The satellite signal is received through the antenna to obtain the image transmitted by the TV station . Xiao Bian still has a fresh memory , When I was a child, I had a black-and-white TV at home , It's near the electric pole in front of the house . Xiaobian was totally immersed in Guangdong TV Pearl River Station and Guangdong TV Lingnan station in his childhood , When I was a little boy, I was able to speak Cantonese by Guangdong TV Zhujiang station . Of course , Society is developing , Technology is improving , After college , Xiaobian used to watch TV in his hometown “ Big pot ” 了 , Here's the picture , Our native dialect is “ Stove car ”（ Our native dialect , The cooking pot is called “ vehicle ”,“ Stove car ” It's a big iron pot , It was specially used to cook pig food when I was young ）.

Four 、 computer network

There is no agreement on the definition of computer network , The simplest definition is ： Some interconnected 、 Autonomous computer collection . Generally speaking, it is a network connected between computers , The most primitive and smallest computer network is that two computers are directly connected through a network cable . At first, it was just a network used by computers to transfer files . Now our computer network , It can transmit voice very quickly 、 Images 、 Digital information, etc . When people talk about the Internet , It all refers to the computer network . Usually , We sometimes talk about “ Computer communication network ”、“ Computer Internet ”、“ Internet ”、“ The Internet ” Now it all refers to the computer network .

Two of the most important features of computer networks ： 1) Connectivity ; That is, all computers in the same network , Can communicate with each other , When used, it is just like that every computer is directly connected to each other ; 2) share ： Resource sharing .

5、 ... and 、 LAN

LAN LAN（Local Area Network）, Confined to a small area in the ground （ Like our home 、 In a building or an enterprise ） The computer 、 The workstation 、 Servers and other computer equipment pass through switches 、 A network interconnected by network devices such as routers . We can connect two computers directly through Ethernet cable , You can build a minimal LAN , The two computers can transmit data through this network cable 、 File sharing and so on .

6、 ... and 、 Wide area network

Wide area network WAN（Wide Area Network） There is no exact definition of Wan , At this stage , Generally speaking, the WAN refers to the Internet or the Internet .

7、 ... and 、21 The historical process of the Internet in the 21st century

2000 year 5 month 17 Japan , China Mobile Internet (CMNET) Put into operation . On the same day , China Mobile officially launched “ gotone WAP( Wireless application protocol )” service .2000 year 11 month 10 Japan , China Mobile launched “ Mobile dreamnet project ”, Build openness 、 cooperation 、 Win win industrial value chain .

2001 year 12 month 22 Japan , China Unicom CDMA The first phase of the mobile communication network project was completed on schedule , And in 2001 year 12 month 31 Day is all over the country 31 A province 、 Autonomous region 、 The municipality directly under the central government has been put into operation . China Unicom CDMA Construction of network , It marks that the development of China's mobile communication technology has entered a new field .

2002 year 5 month 17 Japan , China Mobile took the lead in officially launching nationwide GPRS Business .11 month 18 Japan , China Mobile Communications and the United States AT&T Wireless The company jointly announced , Two companies GPRS The international roaming service was officially opened .

2003 year 4 month 9 Japan , China Netcom Group announced the public computer Internet of China Netcom Group and Chinatelecom group in Beijing （CHINANET） Implement split , And grandly launched the new business brand of China Netcom Group “ Broadband China ”.