Find the development history of communication signals and introduce their advantages and disadvantages, such as the development history from 1G to 4G, preferably in detail. E-mail 520yespp @163.com.

Who remembers a clumsy but symbolic "big brother"? Maybe many people don't understand that in the history of China's communication industry, "mobile phone" represents the 1G era of mobile communication, and then the technology evolved to 2G, and then to the increasingly popular 3G. In the future, we are about to usher in the 4G era.

According to experts, in the past ten years, great changes have taken place in the world telecommunications industry: mobile phones have gradually replaced fixed telephones; From single voice call to data and value-added; Wireless internet services are gradually emerging; On-demand business has gradually become a fashion business.

Evolution history of 1G to 4G

With the continuous progress of communication technology, we have experienced the era of 1G, 2G and 3G, and are approaching the 4G era. What kind of technological innovation do these communication technologies represent?

A chart from Wikipedia clearly describes the differences between the four generations of mobile communication technologies and the international evolution history from 1G to the upcoming 4G.

1G, simulating cellular network, starting with 1983. The first generation of mobile communication technology used multiple cellular base stations, allowing users to move freely during the call and seamlessly transmit the call between adjacent base stations.

2G, digital network, from 199 1. Different from the previous generation, the second generation mobile communication technology uses digital transmission instead of analog, which improves the efficiency of telephone network search. During this period, the number of mobile phone users increased rapidly, and prepaid mobile phones became popular. The establishment of a large number of base stations shortens the distance between base stations, reduces the coverage area that a single base station needs to bear, and helps to provide higher quality signal coverage. Therefore, the receiver does not need to be designed as a high-power and compact mobile phone as before.

During this period, the SMS function was first applied on the GSM platform, and then extended to all mobile phone systems. Paid content such as ringtones has become a new profit growth point. GSM (Global System for Mobile Communications) has become the most popular mobile communication standard in the world. Because of internal compatibility, international roaming becomes easier. 80% of the global 2G network is GSM, covering 3 billion people in 2 12 countries/regions.

3G, high-speed IP data network, 200 1 start. The biggest feature of the third generation mobile communication technology is that packet switching replaces circuit switching in data transmission. A few years ago, a USB dongle connected to the mobile Internet on a computer came out. Circuit switching realizes voice and other data transmission between mobile phones; Packet switching converts voice into digital format and transmits data packets including voice, video and other multimedia content through the Internet.

4G, all-IP data network, since 2009. In the 4G era, circuit switching will disappear completely. All voice calls will be made in the form of VoIP through digital conversion. Therefore, in 4G networks, you can rely on wired or wireless networks, and you don't necessarily need mobile signal coverage.

From "mobile phone" to smart phone

From 1G to 4G, mobile communication technology is changing with each passing day. It represents not only technological innovation, but also the continuous satisfaction and progress of ordinary people in communication needs.

1990, a kind of "mobile phone" appeared in China. The mobile phone with a price as high as 20,000 to 30,000 yuan has only one function: mobile phone calls. This is the era of1g. At that time, walking on the road with a brick-like "mobile phone" was a status symbol. Because mobile communication at that time belonged to a few people.

2G is the second generation digital GSM network that we are familiar with. After more than ten years of construction and development, Jiangxi Mobile has built the largest wireless communication network in Jiangxi, providing the best communication services for our customers. The second generation mobile communication system makes up for the shortcomings of the first generation voice service, with better confidentiality, larger network capacity, lower power consumption of mobile phones and richer mobile phone number resources.

In the 2G era, mobile phones have become an indispensable part of everyone's life, and even influenced and changed our living habits. Mobile phones are getting smaller and smaller, but their functions are becoming more and more powerful, and the services provided by mobile communication providers are becoming more and more abundant. Since 1999, Jiangxi Mobile has successively launched many services such as SMS, mobile secretary, mobile voice, IP phone, WAP, mobile banking, mobile newspaper and "I love my home". Later, new services appeared one after another, such as MMS, CRBT, mobile newspaper, mobile securities, mobile TV, 12580.

In 2009, Jiangxi communication industry entered the 3G era. On June 6, 2009, the first TD antenna of Jiangxi Mobile was erected in the base station of Nanchang Electric Power Technician School. On February 28th, 2009, Jiangxi Mobile officially launched TD-SCDMA, taking the lead in opening Jiangxi 3G network. The successful completion of the TD-SCDMA network construction of Jiangxi Mobile depends on the hard work of mobile employees and the strong support of the government. It is the first time in China that Jiangxi provincial government has written its support for TD construction into the government work report. Jiangxi Province has also incorporated TD-SCDMA network construction into the overall social development plan and special infrastructure plan of Jiangxi Province, and established a leading group for TD-SCDMA construction coordination to fully support and coordinate the development of TD-SCDMA network construction. In order to let 3G services enter people's lives as soon as possible, a large number of network planners and engineers of Jiangxi Mobile have devoted themselves to TD network construction. They overcame the influence of bad weather, took on high-intensity work pressure, put in continuous fighting, and completed the construction and optimization of more than 700 base stations in half a year.

The main difference between 3G and 2G is the speed of voice and data transmission. It can better realize global wireless roaming, handle images, music, video streams and other media forms, and provide various information services including web browsing, teleconference, e-commerce and so on. With the arrival of 3G, mobile phone manufacturers have ushered in a feast of brand-new smart phones. Smart phones have not only made new breakthroughs in appearance and function, but also greatly improved chip technology and technology.

4G brings broadband Internet to mobile phones.

With the opening of 3G network, the most intuitive feeling of users is that the speed of accessing the Internet through 3G network card is much faster than that in the 2G era. Although many people think that 3G is mainly based on calls, surfing the Internet is an incidental function, especially the application development closely related to life and work is not mature enough and diversified, which makes many users have insufficient motivation to automatically switch to 3G and become 3G users. However, judging from the importance and progress made by countries all over the world, the future 4G network will definitely enter the practical application and profoundly affect the form of the next generation Internet.

The most typical feature of 4G network is that the network speed is greatly improved, and the download speed is as high as 100Mbps. If 2G and 3G are commendable for the development of human informatization, then the future 4G communication will give people real freedom of communication and will completely change people's lifestyle and even social form. In the need of high-speed services, such as video calls, high-definition TV, online games, movie downloads and so on. Now 3G still has no effect. In the 4G era, related technologies will move broadband Internet access to mobile phones, and the application of wireless broadband will be popularized. Consumers will mainly use the mobile internet, and the call function will take a back seat. With the support of high-speed network, the "killer" network problems such as videophone, mobile TV and mobile payment that plague operators in the 3G era will no longer exist. At present, all the services that can be supported by wired networks will exist in the form of wireless, which exceeds the limitation of space.

If the gradual popularization of 3G technology is making more and more people surf the Internet through mobile phones, then the popularization of 4G technology will definitely make a leap in the number of users surfing the Internet through mobile phones, and finally realize the interconnection from people to people and networks. It is estimated that by 20 13, the number of users accessing the Internet by mobile phones will exceed the number of users using computers, reaching 178 billion, and the number of users accessing the Internet by mobile phones such as smart phones will be even more impressive. At that time, the 4G mobile phone will become a terminal connected to the network, and its call function will only be its incidental function. The functions that can be realized by wired network can be realized by its handheld terminal. Mobile phones will become classrooms, banks and cinemas in the palm of your hand, which can provide location services and remotely control washing machines and microwave ovens at home, because cars, refrigerators and microwave ovens can all be embedded with SIM cards and become a terminal of mobile communication networks.

China Mobile actively promotes the construction of 4G networks, and has carried out TD-LTE scale networking experiments in Beijing, Tianjin, Shanghai, Nanjing, Hangzhou and Guangzhou 14 cities. What's more, Jiangxi's 4G network is also under construction, and customers can also experience the 4G network in Nanchang Bayi Mobile Business Hall.