What is the third generation mobile communication technology?

3G, the third generation, means the third generation digital communication in Chinese. The first generation analog mobile phone (1995) can only make voice calls; From 1996 to 1997, the second generation of GSM, TDMA and other digital mobile phones (2G) have added the function of receiving data, such as receiving mail or web pages; The main difference between the third generation and the first two generations is that the speed of transmitting sound and data has increased. It can better realize seamless roaming around the world, handle various media forms such as images, music and video streams, and provide various information services including web browsing, teleconference and e-commerce. At the same time, we should also consider the good compatibility with the existing second-generation system. In order to provide this service, the wireless network must be able to support different data transmission speeds, that is, at least 2Mbps (megabits per second), 384kbps (kilobits per second) and 144kbps in indoor, outdoor and driving environments respectively. (This value will vary according to the network environment).

Compared with the first generation of analog mobile phones (1G) and the second generation of GSM, TDMA and other digital mobile phones (2G), 3G communication has many names, which are defined by ITU as "IMT-2000" (International Mobile Phone 2000) and called "UMTS" by European telecom giants.

About 3G numbering

On April 1 day, 2008, China Mobile released its numbers in eight cities, namely, Beijing, Shanghai, Tianjin, Shenyang, Guangzhou, Shenzhen, Xiamen and Qinhuangdao, and officially launched the social service test and commercial trial of TD-SCDMA. Under the focus of expectation, wait-and-see and doubt, the 3G curtain in China has finally been officially opened by TD-SCDMA, a domestic 3G standard that has experienced a decade-long technological maturity process. China's 2008 will not only attract worldwide attention because of the Olympic Games, but also go down in history as "the first year of 3G".

It is understood that Beijing released 15000 and Shanghai released 10000. However, in a short period of one week, 3G has exposed many problems, such as unstable signals and intermittent calls ... These problems have also made TD the focus of people's attention.

TD has been growing in controversy since its birth. Today, TD has been put into commercial trial, and the real test has just begun.

3G hotspot

On April 1 2008, China Mobile opened TD numbers in eight Olympic cities. China 3G has finally been launched, which has finally made people who are eager for 3G look forward to it. However, after the network is ready, the next problem is the terminal. Many friends don't know much about 3G, let alone what kind of mobile phones can be used in China. Many friends even think that as long as they buy a parallel 3G mobile phone, they can use it in China. Actually, it's not. Because the 3G standard used in China is TD-SCDMA, and most 3G mobile phones in parallel market are WCDMA, these products can't be used in the domestic market, but the very popular iPhone and most domestic mobile phones are still in the 2G era.

What kind of products can I use China Mobile's TD card? Today, I will introduce several products that are very representative in network and transmission mode. Friends who are interested in 3G technology may wish to consider it.

3rd generation

In May 2000, the International Telecommunication Union (ITU) ITU)www.tnzt.com determined three mainstream wireless interface standards, namely, W-CDMA, CDMA2000 and TD-SCDMA, and wrote them into the 3G technical guide International Mobile Communication Plan 2000 (IMT—2000 for short). CDMA is the abbreviation of code division multiple access, which is the technical basis of the third generation mobile communication system. The first generation mobile communication system adopts frequency division multiple access (FDMA) analog modulation mode. The main disadvantages of the system are low spectrum utilization and signal interference to voice services. The second generation mobile communication system mainly adopts time division multiple access (TDMA) digital modulation mode, which improves the system capacity, and uses independent channels to transmit signaling, which greatly improves the system performance. However, the system capacity of TDMA is still limited and the handover performance is still not perfect. CDMA system shows great development potential with its advantages of simple frequency planning, large system capacity, high frequency reuse coefficient, strong anti-multipath ability, good communication quality, soft capacity and soft handover. Here are some 3G standards:

( 1) W-CDMA

The full name is wideband CDMA, also called CDMA direct spread spectrum, which means wideband code division multiple access. This is a 3G technical specification based on GSM network and a broadband CDMA technology proposed by Europe. It is basically the same as the broadband CDMA technology proposed by Japan and is being further integrated. Its supporters are mainly European manufacturers mainly based on GSM system, and Japanese enterprises are also involved to some extent, including Ericsson, Alcatel, Nokia, Lucent and Nortel in Europe and America, as well as NTT, Fujitsu and Sharp in Japan. This system can be built on the existing GSM network, which can be easily transitioned by system providers. In Asia, where GSM system is quite popular, the acceptance of this new technology is expected to be quite high. Therefore, W-CDMA has inherent market advantages. This standard puts forward the evolution strategy of GSM(2G)-GPRS-EDGE-WCDMA(3G). GPRS stands for General Packet Radio Service, and EDGE stands for Enhanced Data Rate of GSM Evolution. These two technologies are called 2.5 generation mobile communication technologies.

(2)CDMA2000

CDMA2000 is a wideband CDMA technology developed from narrowband CDMA(CDMA IS95) technology, also known as CDMA multicarrier. The standard was put forward by Qualcomm North America Company of the United States, and Motorola, Lucent and Samsung of South Korea all participated in it. At present, South Korea is the leader of the standard. The system originated from the narrow-band CDMAOne digital standard, and can be directly upgraded from the original CDMAOne structure to 3G, with low construction cost. But at present, CDMA is only used in Japan, South Korea and North America, so there are not as many supporters of CDMA2000 as W-CDMA. However, the research and development technology of CDMA2000 is the fastest among the current standards, and many 3G mobile phones have already taken the lead. This standard puts forward the evolution strategy from CDMA IS95 (2G)-CDMA 20001X-CDMA 20003x (3G). CDMA2000 1x is called the 2nd and 5th generation mobile communication technology. The main difference between CDMA20003x and CDMA2000 1x lies in the application of multicarrier technology, which improves the bandwidth by using three carriers. At present, China Unicom is adopting this scheme to transition to 3G, and has built a CDMA IS95 network.

(3)TD-SCDMA

The full name is time division-synchronous code division multiple access, which is a 3G standard independently formulated by Chinese mainland. 1On June 29th, 999, the Institute of Telecommunications Science and Technology of the former Ministry of Posts and Telecommunications of China (Datang Telecom) proposed to ITU. The standard integrates international leading technologies such as smart wireless, synchronous CDMA and software radio, and has unique advantages in spectrum utilization, business support flexibility, frequency flexibility and cost. In addition, due to the huge market in China, the standard has attracted the attention of major telecom equipment manufacturers, and more than half of the equipment manufacturers in the world 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 upgrading GSM system to 3G.

(4)WiMAX

The full name of WiMAX is Worldwide Interoperability for Microwave Access, also known as 802. 16 wireless metropolitan area network, which is another broadband wireless connection scheme for enterprises and home users. Combining this technology with microwave equipment with or without authorization will expand the broadband wireless market and improve the awareness of enterprises and service providers because of its low cost. On June 65438+1October 65438+1October 9, 2007, WiMAX was officially approved as the fourth global 3G standard after WCDMA, CDMA2000 and TD-SCDMA.

Universal mobile telephone communication system

As early as the early 1990s, the European Telecommunications Standards Institute (ETSI) began to seek technical solutions for 3G standards. The ambitious 3G technology is collectively called UMTS (Universal Mobile Telecommunication System), which means Universal Mobile Telecommunication System. Broadband CDMA (bandwidth 5MHz) scheme is one of its many schemes. Since then, Japan's active participation has greatly promoted the globalization of 3G standards. 1998, Japan and Europe reached an agreement on the key parameters of the broadband CDMA proposal, which officially became the selected technical scheme of the air interface in FDD (frequency division duplex) band of UMTS system, so it was commonly known as WCDMA. W is broadband, which is different from the narrowband CDMA (bandwidth 1.25MHz) standard originating from North America.

The continuous development of the above technical standards is reflected in the four versions of UMTS standard of 3GPP: R99, R4, R5 and R6. Formed a huge and relatively independent standard system. WCDMA is the earliest and most perfect preferred air interface, which is widely used by 3G operators in Europe, Asia and America.

third generation

Japanese mobile communication giant NTT DoCoMo launched the world's first 3G service based on WCDMA standard on/KOOC-0/0/2006. At present, Asia has become the fastest growing region of 3G, followed by Europe, and the United States is far behind in technical preparation due to lack of enthusiasm. In addition to Japan and South Korea, Thailand and Hong Kong also issued 3G licenses. Taiwan Province Province will soon issue 3G licenses. It is estimated that 3G licenses will be issued in the Mainland before the end of 2007, and the market is expected to issue two or three licenses.

supplement

Model arrangement details:

Each series of Nokia also has regularity:

The model number is XX00, such as 3300, 6600, etc. These are the most distinctive and functional models in this series. 3300 is an MP3 music mobile phone with obvious positioning and great charm. 6600 is a classic.

The model is XY00, such as 2100,3100,3200. These machines are the main models in this series. Nokia's first GSM folding machine 7200 is an example. Among them, the model of X 100 is more important, and the positioning of X 100 is the main model in its series. Observing the sales of these X 100 models, we can see that this is indeed the case. X 100 models are all models with very stable sales and good reputation. They are the main force for Nokia to occupy market share.

The model is XY 10, such as 32 10, 55 10, 76 10, 88 10, etc. Most of them are mobile phones with some new Nokia functions or innovative significance. For example, 32 10 is Nokia's first mobile phone with built-in antenna. Many new functions and ideas are presented to the world for the first time on XY 10 model.

The model is XY20, such as 3 120, 3220, 6820, etc. These machines are generally based on the same model as their XY position number, which is more perfect and mature than the previous models. For example, 3 120 is based on 3 100, and 3220 is based on 3200. 3 120 inherited the performance of 3 100 and replaced it with a chrome-plated silver shell, which is called 3 100 suitable for young business people. 3220 has the functions and features of 3200, such as changing inserts at will, and using the "flash message" pioneered by Nokia.

The model is XY30, which is basically a mature and perfect summary of the previous XY00 model. Such as 3230, 6230, 6630. Among non-smart phones, except the screen 6230, the function is the strongest. 6230 is definitely the strongest of the 6 series in 2004, and it is also a hot-selling model in the market. 3G mobile phone 6630 is one of Nokia's strongest mobile phones at present, and all configurations are in the forefront. 3230 not only inherits the personality of Series 3 with its unique shape, but also enriches the functions of Series 3 models by adding an intelligent operating system.

The model is XY40, which is not very popular and not very successful.

The model is XY50, most of which are powerful mobile phones of their own series, and some of them are smart phones. For example, 7250 and 7650 of the nobles in the 7 series, and 3650 in the 3 series.

The model is XY60, and most of them are smart phones. Such as 3660 and 6260.

The model number is XY70, and the new model suffix. It is a supplement or another interpretation of different market divisions of the same series of vehicles. For example, compared with 6630 and 6670, the function is slightly simplified, forming another grade choice. Compared with the 7200, the 7270 keeps the appearance of the folding machine, improves the screen and adds some functions. The important thing is that the shape of 7270 is retro and elegant, not the fashion style of 7200.

The model number is XY80. If 2280 of CDMA network is excluded, it is the new model suffix.

The model is XYZ5, except that 3355, 8855 and 6255 are another version of XYZ0 with CDMA network. For example, 3 105 is relative to 3 100, 3 125 is relative to 3 120, and 6225 is relative to 6220. Usually, the function of CDMA version is a little different from that of its brother in GSM version. For example, 3 100 is a fourth chord and 3 105 is a 16 chord.

The model is XYZ8, which can be regarded as a variant of its XYZ0 model. For example, compared with 6 108, 3 108 and 3 100, 6 108 has outstanding features of handwriting input. It seems that these two 8-digit mantissa machines are specially designed for China people who are used to writing Chinese characters, and they are listed in Chinese. In addition, compared with 1 108, the green backlight of 1 108 is changed to white, and it becomes1108. 3 128 is a folding machine only listed in Chinese mainland.

Author: Li Nuo

Recently, Nokia issued a statement at a party: Nokia used to use four digits as the standard for naming mobile phones, but it began to change after the emergence of N series multimedia and E series business machines last year. At present, the previous rule of naming only four digits has been broken, and a brand-new naming rule has emerged.

With more and more mobile phone models and fewer and fewer models, Nokia's original four-digit naming principle is not enough, and new naming principles need to be formulated. During the four-digit naming period, some models were complicated and difficult to remember, which also led to consumers' doubts.

Nokia's early 1 and 2 series are entry-level models; Series 3 is a fun model; Series 5 is a sports series; 6 series is a series of excellent business machines; 7 series is a fashion series; Series 8 is an outstanding series; 9 Series is a high-end smartphone.

Starting from this year, in addition to the N series of multimedia and the E series of enterprise solutions, the original four-digit series will be re-integrated and divided into seven categories: classic, comfortable, contemporary, expressive, active, fashionable and advanced. Classic is a classic business series, Comfort is an introductory low-level series, Contemporary replaces the original excellent series, Expression emphasizes self-style, Active is a sports mobile phone, Fashion is a fashion mobile phone, and Premium replaces the distinguished series.

In addition to integrating the four-digit model, S, X and F will be added at the back of the model in the future, representing three forms of sliding cover machine, vertical machine and folding product respectively. Only the same model will continue to develop in the future. Take the representative model 6500 of the contemporary series as an example. There may be 6,500s, 6,500x, 6,500f, or even 6500SA, 6500SB, and 6500SC in the future, and different codes will be added after the models, instead of continuing to arrange them by numbers, such as 650 1, 6502, and 65000. Therefore, Nokia 5500 model will hang Sports, Nokia 5300 will hang XpressMusic and Nokia 7370 will hang LAmour.

3G Status in China

On April/KOOC-0/2008, China Mobile Communications Group Co., Ltd. carried out the social service test and commercial trial of the third generation mobile communication (3G) and "China standard" TD-SCDMA in eight cities, with the number of/KOOC-0/57. It marks the official commercial launch of the third generation mobile communication (3G) standard TD in China. According to reports, the first batch of social business tests will invite 20,000 users from different industries and departments to provide 2,000-4,000 yuan of mobile phones and data card terminals free of charge, and give the test users a monthly telephone subsidy in 800 yuan.

Judging from China Mobile's public tariff standard, ordinary call charges TD are even cheaper than 2G. TD monthly fee is 50 yuan/month, and the local basic call fee is 0.40 yuan/minute, and the caller is free; The domestic roaming call fee is 0.60 yuan/minute, and the called party is 0.40 yuan/minute; Domestic long-distance call charge is 0.07 yuan /6 seconds; The short message fee is 0. 1 yuan/message inside the network and 0. 15 yuan/message outside the network, and the reception is free.

TD new service-local communication of videophone calls 0.6 yuan/min, and the called party is free; Domestic roaming calling 0.9 yuan/min, called 0.60 yuan/min; Domestic call 0. 10 yuan /6 seconds. In addition, China Mobile has also launched three TD voice packages and data card packages, all of which are lower than the current G network level.