(1) W-CDMA

Also known as WCDMA, the full name is Wideband CDMA, also known as CDMA Direct Spread, which means wideband code division multiple access, which is based on GSM The 3G technical specification developed by the Internet is the broadband CDMA technology proposed by Europe. It is basically the same as the broadband CDMA technology proposed by Japan and is currently being further integrated. Its supporters are mainly European manufacturers based on the GSM system, and Japanese companies are also more or less involved, including European and American Ericsson, Alcatel, Nokia, Lucent, and Nortel, as well as Japanese manufacturers such as NTT, Fujitsu, and Sharp. This system can be set up on the existing GSM network, making the transition easier for system providers. The acceptance of this new technology in Asia, where the GSM system is quite popular, is expected to be quite high. Therefore, W-CDMA has inherent market advantages. This standard proposes the evolution strategy of GSM (2G)-GPRS-EDGE-WCDMA (3G). GPRS is the abbreviation of General Packet Radio Service (General Packet Radio Service), and EDGE is the abbreviation of Enhanced Data rate for GSM Evolution (GSM Evolution with enhanced data rate). These two technologies are called 2.5-generation mobile communication technologies.

(2)CDMA2000

CDMA2000 is a broadband CDMA technology developed from narrowband CDMA (CDMA IS95) technology. It is also called CDMA Multi-Carrier and is developed by Qualcomm North America. The leader proposed that Motorola, Lucent and South Korea's Samsung, which later joined, all participated, and South Korea has now become the leader of the standard. This system is derived from the narrow-band CDMAOne digital standard and can be directly upgraded from the original CDMAOne structure to 3G with low construction costs. However, the only regions currently using CDMA are Japan, South Korea and North America, so CDMA2000 does not have as many supporters as W-CDMA. However, the research and development technology of CDMA2000 is currently the fastest among all standards, and many 3G mobile phones have already been launched. This standard proposes an evolution strategy from CDMA IS95 (2G)-CDMA20001x-CDMA20003x (3G). CDMA20001x is called the 2.5th generation mobile communication technology. The main difference between CDMA20003x and CDMA20001x is the application of multi-carrier technology, which increases the bandwidth by using three carriers. China Unicom is currently using this solution to transition to 3G and has built a CDMA IS95 network.

(3)TD-SCDMA

The full name is Time Division - Synchronous CDMA (Time Division Synchronous CDMA). This standard is a 3G standard independently developed by mainland China on June 29, 1999. On the same day, the Telecommunications Science and Technology Research Institute of the former Ministry of Posts and Telecommunications of China (Datang Telecom) proposed to the ITU. This standard integrates today's leading international technologies such as smart wireless, synchronous CDMA and software radio, and has unique advantages in spectrum utilization, flexibility in business support, frequency flexibility and cost. In addition, due to the huge domestic market in China, this standard has attracted the attention of major telecommunications equipment manufacturers. More than half of the world's equipment manufacturers have announced that they can support the TD-SCDMA standard. This standard proposes a direct transition to 3G without the intermediate link of 2.5 generation, which is very suitable for the upgrade of GSM system to 3G.

In addition,

Currently China Mobile has obtained the TD-SCDMA license and has plans to promote it nationwide, while China Unicom has obtained the WCDMA and CDMA2000 licenses, but China Unicom is currently only launching it in Macau. Although the CDMA2000 standard 3G network has been established, it will take time for the WCDMA 3G network to be promoted nationwide.

The parallel-imported 3G mobile phones we buy on the market are basically WCDMA standard. We can only wait for China Unicom to quickly launch the WCDMA 3G network