At present, the most widely used mobile phones in the world are GSM and CDMA. GSM is the most popular in Chinese mainland and Taiwan Province province, and CDMA and PHS mobile phones are also very popular. These are the so-called second generation mobile phones (2G). They are all in digital format. Besides voice communication, they can also send and receive short messages (SMS), multimedia messages (MMS) and wireless application protocol (WAP).
Generally, the appearance of a mobile phone should include at least one LCD screen and a set of buttons (some touch-screen phones reduce buttons).
In addition to typical telephone functions, some mobile phones also include many functions, such as PDA, game machine, MP3, camera, recording, camera, GPS and so on. And there is a trend to develop PDA with mobile phone function.
Development history
1G
The first generation of mobile phones (1G) refers to analog mobile phones, which appeared in Hong Kong, the United States and other film and television works in the 1980s and 1990s. The first person to develop a mobile phone was Dr. Cooper from Motorola, USA. Due to the limitation of battery capacity and the development of analog modulation technology, such as huge antenna and integrated circuit, this mobile phone has a square appearance and can only be moved, but not portable. Many people call this kind of mobile phone "brick" or "Black King Kong".
There are many formats of this kind of mobile phone, such as NMT, AMPS, TACS, etc., but frequency division multiplexing can only be used for voice communication, with unstable reception effect, insufficient confidentiality and insufficient wireless bandwidth. In this case, the mobile phone is similar to a simple radio duplex station, the call is locked on a certain frequency, and you can use FM radio to eavesdrop on the call.
2G
The second generation mobile phone (2G) is also the most common mobile phone. Usually, these mobile phones use very mature standards such as PHS, GSM or CDMA, with stable call quality and appropriate standby time. In the second generation, in order to meet the needs of data communication, some intermediate standards are also supported on mobile phones, such as GPRS supporting MMS service, WAP service for Internet service, and various Java programs.
third generation
3G, the abbreviation of English 3rdGeneration, refers to the third generation mobile communication technology. Compared with the first generation of analog mobile phones (1G) and the second generation of GSM, TDMA and other digital mobile phones (2G), the third generation of mobile phones generally refers to a new generation of mobile communication systems that combine wireless communication with multimedia communication such as the Internet. It can handle images, music, video streams and other media forms, and provide a variety of information services including web browsing, teleconference, e-commerce and so on. In order to provide this service, the wireless network must be able to support different data transmission speeds, that is, in indoor, outdoor and driving environments, it can support at least 2Mbps (megabits per second), 384kbps (kilobytes per second) and 144kbps respectively.
Future mobile phone
Future mobile phones will focus on security and data communication. On the one hand, strengthening the protection of personal privacy, on the other hand, strengthening the research and development of data services will introduce more multimedia functions. Mobile phones will have more computing power and become personal information terminals, not just the functions of calling and short messages.
Mobile phones will be more intelligent, miniaturized, safe and multifunctional.
Current mobile phone
At present, the most widely used mobile phones in the world are GSM and CDMA. In Chinese mainland and Taiwan Province Province, GSM is the most popular, and CDMA and PHS mobile phones are also very popular. These are the so-called second generation mobile phones (2G). They are all in digital format. Besides voice communication, they can also send and receive short messages (SMS), multimedia messages (technology) and wireless application protocol (WAP).
Generally, the appearance of a mobile phone should include at least one LCD screen and a set of buttons (some touch-screen phones reduce buttons). In addition to the typical telephone functions, some mobile phones also include PDA, game machine, MP3, camera, recording, photographing, positioning and other functions, and there is a tendency to develop into handheld computers with mobile phone functions.
The first generation mobile phone (1G) refers to analog mobile phone, which has many formats such as NMT, AMPS, TACS, etc., but it can only communicate through voice, so the reception effect and confidentiality are insufficient, and wireless broadband is not fully utilized. After the second generation of mobile phones appeared, people called these analog mobile phones the first generation. The mobile phone used in the third generation mobile communication system (3G) has also been developed, but it has not been widely used because the related network is not popular. One of the initial goals of the third generation mobile phone is to develop a wireless communication system that can be used all over the world, but the actual end result is that there are many different standards, mainly WCDMA, CDMA2000 and TD-SCDMA. These new standards are based on CDMA (code division multiple access) technology, and have further developed in bandwidth utilization and data communication.