Now "3G Communications" is going to be the oral Zen on the mouth, then you know what is 3G communication? The so-called 3G, in fact, its full name is 3RD generation, meaning the meaning of the third generation of digital communications. In 1995, the first generation of digital phones can only conduct voice calls; while the second-generation digital phones that appear in 1996 to 1997 add the functions of receiving data, such as accepting email or web pages; third generation with the first two generations The main difference is to increase the speed of transmission and data, it can handle multiple media forms such as images, music, video streams, providing a variety of information services including web browsing, conference calls, e-commerce. Relative to the first generation of simulated system mobile (1G) and the second generation of GSM, TDMA and other digital mobile phones (2G),
The name of 3G communication has many names. The ITU is specified as "IMT-2000" (International Mobile Phone 2000) standard. Europe's telecommunications industry giants call it "UMTS" universal mobile communication system. This standard specifies that the transfer terminal is moved at a speed of driving, and its transmission data rate is 144 kbps, outdoor stationary or walking rate is 384 kbps, and the room is 2 Mbps. But these requirements do not mean that the user can reach 2Mbps because the indoor rate will depend on the detailed frequency planning in the building and the tightness of the organization and operator collaboration.
International Telecommunications Union (ITU) determines that the three mainstream wireless interface standards of 3G communication are W-CDMA (wide frequency division multiple access), CDMA2000 (multi-load division multiplexed spread modulation) and TDS-CDMA (time division synchronization code division) Multiple access). The W-CDMA standard mainly originated in the early third-generation wireless research activities in Europe and Japan, which is used on the existing GSM network. For system providers, it can transition easily, the main supporter of this standard. European, Japan, South Korea. At the end of last year, the US AT & T Mounting Business Branch also announced WCDMA for its own third-generation business platform. The CDMA2000 system is primarily proposed by the US Qualcomm North America. Its construction cost is relatively low, and the main supporters include Japan, South Korea and North America and other regions and countries. The TD-SCDMA standard is based on China's first proposal and in this wireless transmission technology (RTT), and the TD-SCDMA standard has completed the TD-SCDMA standard, which has become a CDMA TDD standard. This is China Mobile Communications A creative and the contribution of China's development of third generation mobile communications. In the competition with the 3G standards proposed in Europe, the 3G standards proposed by the United States, China's proposed TD-SCDMA has officially become one of the world's 3G standards, which marks that China has entered the world's leading in the field of movement communications.
The 3G mobile phone is entirely the product of the communication industry and the computer industry, and it is really too big compared with the previous mobile phones, so more and more people began to call this new mobile communication product as "personal communication terminal." Even people who are the most exterior of the communication industry can easily judge whether a mobile phone is "third generation": The third generation of mobile phones have a large color display, often touching. In addition to the high-quality daily communication, 3G mobile phones can also be multimedia communications. Users can write directly on the touch display of the 3G mobile phone, and send them to another mobile phone, while the required time may not have one second. Of course, you can also transfer this information to a computer, or download some information from your computer; users can use 3G mobile phones directly to access the email or browse the web; there will be a lot of 3G mobile phone comes with a camera, this Users will make computer meetings using mobile phones, even make digital cameras a "more".
3G communication is the introduction of the mobile communication market experienced the first generation of simulation technology, which is introduced into the schedule in the booming of the second-generation digital mobile communication market. In today's Internet data business, the 3G mobile communication system has also seen the dawn of the market in the context of fixed access rate (HDSL, ADSL, VDSL), and benefits the telecom operator, communication equipment manufacturer and ordinary. The user is concerned.
