The third generation mobile communication technology (3rd-generation, 3G) refers to cellular mobile communication technology that supports high-speed data transmission. 3G service can transmit voice and data information at the same time, and the rate is generally above several hundred kbps. Currently, there are four standards for 3G: CDMA2000, WCDMA, TD-SCDMA, and WiMAX.
4G is the abbreviation of the fourth generation of mobile communications and its technology. It is a technical product that integrates 3G and WLAN and can transmit high-quality video images and the image transmission quality is comparable to high-definition TV. The 4G system can download at a speed of 100Mbps, which is 2,000 times faster than dial-up Internet access, and the upload speed can also reach 20Mbps, and can meet the requirements of almost all users for wireless services. In terms of price, which users are most concerned about, 4G and fixed broadband networks are comparable in price, and the billing method is more flexible. Users can determine the services they need based on their own needs. Additionally, 4G can be deployed where DSL and cable modems don't have coverage, and then expanded throughout the region. Obviously, 4G has incomparable advantages.
CDMA (Code Division Multiple Access), also known as Code Division Multiple Access, is a technology used in wireless communications. CDMA allows all users to use all frequency bands (1.2288Mhz) at the same time and transmit the data sent by other users to The signal is treated as noise, and there is no need to consider signal collision issues at all. The voice coding technology provided in CDMA has better call quality than the current GSM, and can reduce the noise in the surrounding environment when users are talking, making the call clearer. In terms of security performance, CDMA not only has a good authentication system, but also uses codes to distinguish users due to its transmission characteristics, and its ability to prevent eavesdropping is greatly enhanced. Wideband CDMA (WCDMA) wideband code division multiple access transmission technology is an important basic technology of IMT-2000 and will be one of the third-generation digital wireless communication system standards.