Modern communication technology 2022

 

Modern Technology Information

Concept

Internet The so-called communication, the simplest understanding, is also the most basic understanding, that is, the method of communication between people. Whether it is a telephone or the Internet, the most basic problem to be solved is human-to-human communication. Modern communication technology is how to use the latest technology to continuously optimize various ways of communication with the continuous development of science and technology so that the communication between people becomes more convenient and effective. This is a systematic subject, and 3G is one of the important subjects. 

Overview

Communication technology and the communications industry have been one of the fastest-growing areas since the 1980s. This is true both internationally and domestically. This is one of the important signs that human beings enter the information society. Communication is the exchange of information. In this sense, communication has existed since ancient times. Conversation between people is communication, and expressing emotions with gestures can also be considered communication. In the future, the use of beacon fires to transmit the war situation is communication, and the transmission of documents between the fast horse and the post station is of course also communication. Modern communication generally refers to telecommunications, which is called telecommunication internationally. 

 

The development of communication is divided into the following three stages: The first stage is the language and text communication stage. At this stage, the communication method is simple and the content is single. The second stage is the electrical communication stage. In 1837, Morse invented the telegraph and designed the Morse telegraph code. In 1876, Bell invented the telephone. In this way, electromagnetic waves can be used to transmit not only text but also voice, which greatly speeds up the development of communications. In 1895, Marconi invented radio equipment, thus pioneering the development of radio communications. The third stage is the electronic information communication stage. Generally speaking, communication technology is actually the technology of communication systems and communication networks. The communication system refers to all the facilities required for point-to-point communication, and the communication network is all the facilities that can communicate with each other between multiple points composed of many communication systems. The main modern communication technologies include digital communication technology, program-controlled switching technology, information transmission technology, communication network technology, data communication, and data network, ISDN and ATM technology, broadband IP technology, and access network and access technology. 

 

Modern Technology Information

Digital communication is the communication of transmitting digital signals. The analog signal sent by the source is encoded into a digital signal by the wish of the digital terminal, and the digital signal sent by the terminal is converted into a digital signal suitable for transmission with the channel after channel encoding. The signal is modulated on the digital channel used by the system, then transmitted to the pair, and finally transmitted to the sink after the opposite transformation. Digital communication has become the most important communication technology found in modern communication networks because of its strong anti-interference ability, convenient storage, processing, and exchange, and is widely used in various communication systems of the modern communication network. Program-controlled exchange technology means that people use a special electronic computer to store the pre-programmed programs in the computer as needed to complete various exchanges in communication. Program-controlled switching was originally developed from telephone switching technology. From the manual switching, automatic switching, electronic switching, and program-controlled switching technology of telephone switching at the beginning, later, due to the continuous expansion of the scope of communication services, switching technology has not only It is only used for telephone exchanges, and can also realize exchanges such as fax, data, and image communication. Program-controlled digital switches have fast processing speed, small size, large capacity, strong flexibility, and multiple service functions, which are easy to change switch functions, facilitate the construction of intelligent networks, and provide users with more and more convenient telephone services. With the transfer of telecommunication services from voice-based to data-based, the switching technology has also gradually shifted from traditional circuit switching technology to packet-based data switching and broadband switching, as well as adapting to the comprehensive characteristics of IP-based services in the next-generation network. Soft switch direction development. 

 

Information transmission technology mainly includes optical fiber communication, digital microwave communication, satellite communication, mobile communication, and image communication. 

 

Optical fiber is a communication method that uses light waves as the carrier frequency and optical fiber as the transmission medium. Its main characteristics are the frequency bandwidth, which is 104~105 times higher than the commonly used microwave frequency; low loss, long relay distance; anti-electromagnetic interference ability; fine wire, lightweight; and corrosion resistance, not afraid of high temperature and so on. 

 

Digital microwave relay communication refers to a communication method that uses electromagnetic waves with wavelengths ranging from 1m to 1mm to transmit signals through relay stations. Its main features are that the signal can be "regenerated"; it is convenient for the connection of digital program-controlled switches; it is easy to use large-scale integrated circuits; however, together with optical fiber communication and satellite communication, it is internationally recognized as the three most promising transmission methods. 

 

In simple terms, satellite communication is the communication between radio communications on the earth using human beings as relay stations on the earth's satellites. Its main features are: long communication distance and investment cost have nothing to do with communication distance; working frequency bandwidth, large communication capacity, suitable for the transmission of various services; stable and reliable communication lines; high communication quality. 

 

The early form of communication belongs to the communication between fixed points. With the development of human society, information transmission is becoming more and more frequent. Mobile communication has developed rapidly because of the advantages of flexible information exchange and obvious economic benefits. The so-called mobile communication is the communication that is realized in motion. Its biggest advantage is that it can communicate while moving, which is convenient and flexible. Mobile communication systems mainly include digital mobile communication systems (GSM), and code multiple access cellular mobile communication systems (CDMA). 

 

The communication network is mainly divided into telephone network, support network, and intelligent network. The telephone network is a telecommunication network that conducts interactive voice communication and opens up telephone services; a complete telecommunication network needs to have several service networks to ensure the normal operation of the service network and enhance network functions, in addition to the service network that mainly transmits information. The support network that improves the quality of network services is the support network. The support network mainly includes the No. 7 signaling network, digital synchronization network, and telecommunication management network. The intelligent network is an additional network structure established based on the original network for fast, convenient, economical, and flexible generation and realization of various new telecommunication services. 

 

In the field of communication, information can generally be divided into three types: voice, data, and image. Data is a combination of digital signals with a certain meaning, such as letters, numbers, and symbols. During transmission, these letters, numbers, and symbols are expressed one by one with discrete digital signals. Data communication is to put such data signals on the data transmission channel. A communication method in which the originally sent data information is correctly restored after reaching the receiving location. Its main features are: man-machine or machine-machine communication, the direct participation of computer in communication is an important feature of data communication; high transmission accuracy and reliability requirements; high transmission rate; the large difference in communication duration. The data communication network is a network composed of data terminal equipment, data exchange equipment, and data transmission links distributed in various places and completes data transmission and data exchange between data terminals under the support of communication protocols. 

 

Modern Technology Information

The data network is the product of the combination of computer technology and the development of modern communication technology. It is the integration of information collection, transmission, storage, and processing, and it develops towards a more advanced complex. Throughout the development of communication technology, although there is only a short history of more than 100 years, it has undergone earth-shaking changes. From the original manual transfer to the later circuit transfer, program-controlled switching, packet switching, ATM switches, and IP routers for packetized core networks; from single landline phones to satellite phones, mobile phones, IP phones, etc., as well as various other services combined with communications and computers, the third generation of communication technology will be launched soon, And the fourth generation of communication in the future, with the development of communication technology, human society has gradually stepped into the information society. 

A Brief History 

1962, the first transatlantic telecast: On July 11, 1962, "Electric Star 1" at Andover Station, Maine, the USA with Gunhey Station in the UK and Puller in France Transatlantic telecasting and transmission of multiplex telephony experiments were successfully conducted between Merde-Hakata stations. 

 

On July 26, 1963, NASA launched the "Syncom 2" (Syncom II) communications satellite to conduct telephone, telegraph, and fax communications between Africa, Europe, and the United States. Since this satellite inclines 30 degrees, its orbit moves in a figure-8 shape relative to the ground, rather than being truly "synchronized", so it cannot be called a "stationary satellite". 

 

Syncom Satellite 

 

On August 23, 1963, President Kennedy concluded his conversation with the Prime Minister of Nigeria, citing Morse's first public telegram message "What a miracle God has done", which was sent by "Syncom" "The first telephone conversation of the communication satellite, the sound traveled more than 72,000 kilometers.

 

In 1964, the world's first geostationary communication satellite: 

On August 19, 1964, the United States launched the "Syncom III" satellite. This is the world's first geostationary communications satellite in geostationary orbit. On December 18, 1958, the United States launched its first communications satellite, which, due to technical reasons, only worked for 13 days. Since then, satellite communication has entered the experimental stage. From 1963 to 1964, the United States launched three experimental geostationary satellites, and only the third satellite, "Synchronous 3", was completely successful. 

In 1964, the satellite communication business was started: On August 20, 1964, the "International Communications Satellite Consortium" headed by US Communications Satellite Co., Ltd. was established, and the following year changed its name to "International Communications Satellite Organization", namely the famous INTELSAT. Headquartered in Washington, the purpose of this organization is to propose and develop a global communications satellite system that can be used equally by all countries in the world to improve their telecommunications services. Established the satellite communication system and the performance standard of the standard earth station, and the satellite communication business has officially become an international commercial business. 

In 1965, the era of synchronous satellite communications began: On April 6, 1965, the International Satellite Communications Organization (INTELSAT) launched a semi-experimental, semi-practical geostationary communications satellite - "Early Bird", and Known as "Intelsat 1", as the world's first practical commercial communication satellite, it provides communication services between North America and Europe, creating a new era of satellite commercial communication. 

 

"Morning Bird" marks the transition of satellite communications from the experimental stage to the practical stage and the beginning of the era of synchronous satellite communications. 

In 1999, the global maritime distress and safety system was launched: On February 1, 1999, the GMDSS system was deployed in various locations around the world. Shipping countries are fully enabled. Different from the widely used distress signal "SOS" before this, GMDSS is a new ship-shore communication system - "Global Maritime Distress and Safety System". 

 

It consists of a satellite communication system and a terrestrial radio communication system. The satellite system also includes two parts: the International Maritime Satellite System and the Very Low Orbit Search and Rescue Satellite System. GMDSS is an advanced system based on advanced satellite communication technology, digital technology, and computer technology. When a ship is in distress, it can not only send rescue information to a larger area more quickly and reliably but also automatically, the semi-automatic method replaces the previous manual alarm method.