Humans have been developing new technologies for communication, which can be traced back to the printing press and even the act of writing itself. But in the past 120 years or so, from the earliest telephone to the modern Internet, communication technology has made rapid development. Modern civilization depends on advanced communication technology. Using electricity to communicate with inventions such as the telephone and telegraph means that people can send information instantly over long distances. Recent developments such as satellites and the Internet have extended communications to all parts of the world and made global news and information commonplace. The continuous improvement and rapid development of communication technology brings you more information options at a lower cost.
Although Samuel Morse's design is the most practical design, various inventors developed various versions of the telegraph in the early 1800s. The system is a simple circuit consisting of batteries, switches and electromagnets. Press the switch key to close the circuit; this energizes the electromagnet, which clicks from a piece of metal. The operator sends a message through a series of coded buttons; the receiving station hears the corresponding click with almost no delay. The telegraph line eventually connects cities across the country, delivering news, business, and personal information.
Phone in the late 1800s, further electrical experiments prompted the inventor to develop the telephone. Like the telegraph, the telephone sends electrical signals to a remote receiver through a wire. The telephone line replaces the intermittent clicks that require training to understand, and conveys the sound of real voice.
The radio system sends voice, data and video through wireless signals. Soon after Bell developed the phone, other inventors, such as Nikola Tesla and Guglielmo Marconi, tried to use high-frequency electronic circuits and antennas to send signals through the air. The radio system introduces the concept of broadcasting, in which thousands of listeners hear voice and music sent by a single transmitter. Today, the concept of radio has expanded from traditional radio stations to mobile phones and wireless data networks.
Although radio waves transmit signals reliably, the ionosphere is a thin layer of high-energy gas that lies above the breathable atmosphere, so long-distance transmission will become complicated. Satellites solve the distance problem by receiving radio signals in space, amplifying them, and retransmitting them to ground receivers thousands of miles away from the original source. In the 1960s, satellite networks allowed the first instantaneous global communications
The Internet originated in a military research project called the Advanced Research Projects Agency Network in the 1960s. This is an early data network that allows computer users in different locations to share information. ARPANET is a testing ground for ideas such as dividing large amounts of data into packets of the same size (called packets). In addition to user data, data packets also have the network addresses of the sender and receiver. Devices called routers pass data packets from one system to another until they reach their destination. Users added more computers to the network, and in the early 1980s, ARPANET became the larger Internet. Initially, researchers used the Internet to store data and simple e-mails, but in the late 1980s, Tim Berners-Lee developed a standard format for text link pages, and the Internet was born. Today, the Internet is constantly evolving in terms of the services it provides and the speed of network hardware.