7.3G Definition

The so-called 3G, in fact, it's all called the 3rd Generation, Chinese meaning is the third generation digital communications. In 1995 came the first generation analogue phones (1G) can only make voice calls; appeared in 1996 and 1997 the second generation GSM, TDMA digital standards such as mobile phones (2G) will increase the receive data, such as receiving e-mail or web ; third generation and two generations before the main difference is in the voice and data transmission speed of the upgrade, it should be better in the global seamless roaming , and processing images, music, video streaming and other forms of media, including web browsing, conference calls, e-commerce and other information services, taking into account also the second-generation system with the existing good compatibility. To provide this service, wireless network must be able to support different data transfer speed, ie indoor, outdoor, and driving environment can support at least 2Mbps (megabits / second), 384kbps (kilobits / second) and 144kbps transmission speed. (This value will change according to the network environment).

Relative first-generation analogue phones (1G) and second-generation GSM , TDMA digital mobile phones, etc. (2G), 3G communication the name of the variety, the ITU defined as "IMT-2000" (International Mobile Telephone 2000) standards, Europe 's telecommunications Industry giants claimed it as "UMTS" Universal Mobile Telecommunications System.
Appendix: 3G = 3 * 1024MB = 3072MB = 3145728KB = 3221225472B

2.5G technology

Has commercial applications for 2.5G mobile communication technology is the interface from 2G into 3G technologies, 3G is a very huge project, the involved and complex multi-level, from the current 2G into 3G can not look on connection between, so there is between 2G and 3G between 2.5G. HSCSD , GPRS , WAP , Bluetooth (Bluetooth), EPOC and other technologies are 2.5G technology, EDGE is a 2.75G technology.

HSCSD (High Speed ​​Circuit Switched Data, high-speed circuit switched data services) is the upgraded version of the GSM network, can greatly enhance the transmission speed to the usual two to three times. Currently Singapore 's M1 and SingTel Mobile are using HSCSD system, the transmission speed can reach 57.6kbps.

GPRS due to its immediate online features for users, can be said that all the time on-line state. GPRS technology can also allow service providers to charge based on the amount of data, rather than simply an on-line time charges. The technology and the GSM network with transmission speeds up to 115kbps.

Entirely to the current GSM EDGE standard as the framework, not only will the GPRS functionality to the limit, but also by the current wireless network to provide broadband multimedia services. EDGE transmission speeds up to 384kbps, can be applied, such as wireless multimedia, e-mail, network information and entertainment video conference.

WAP (Wireless Application Protocol, wireless application protocol) mobile communications and the Internet combined with the first stage product and also we heard the most. This technology allows users to use mobile devices like wireless Internet access, traveled through the small screen between the various sites. These sites must also be WMl (wireless markup language), the Internet equivalent of HTML (hypertext markup language).

Bluetooth (Bluetooth) Bluetooth is a short-range wireless communications technology, electronic devices to each other via Bluetooth and link the traditional wire here, have no useful here. Through the chip wireless receiver equipped with Bluetooth technology, electronic products can be 10 meters distance from each other connected, the transmission speed of up to 1 megabyte per second. Previous infrared interface, the transmission technology needs within the electronic device in the line of sight distance, and now with Bluetooth technology, this trouble can be exempt.

3G standards

International Telecommunication Union (ITU) www.tnzt.com in May 2000 to determine the W-CDMA , CDMA2000 and TD-SCDMA air interface standards for the three mainstream, the text is written guidance 3G technology, "2000 International Mobile Communications Plan" (referred to as IMT-2000). CDMA is Code Division Multiple Access (CDMA) is an abbreviation, is the third generation mobile communication systems technology base. The first generation mobile communication system using frequency division multiple access (FDMA) analog modulation, the main drawback of this system is the use of low frequency spectrum, interference with voice signaling. The second-generation mobile communication system using time division multiple access (TDMA) digital modulation to improve the system capacity, and using an independent channel to send signaling, the system performance greatly improved, but still limited capacity of TDMA systems, handoff performance is still not perfect. CDMA system with its simple frequency planning, system capacity, frequency reuse factor, anti-multipath capability, communication quality, soft capacity, soft-switching characteristics show great potential for development. The following are brief several 3G standards:

(1) W-CDMA


Full-called Wideband CDMA, also known as CDMA Direct Spread, meaning Wideband Code Division Multiple Access, which is based on the GSM network standard developed by the 3G technology, is Europe's wideband CDMA technology, with Japan's basic broadband CDMA technology the same is currently being further integration. Its supporters are mainly the European GSM system based companies, Japanese companies are more or less involved, including Europe, America, Ericsson, Alcatel, Nokia, Lucent, Nortel, and Japan's NTT, Fujitsu, Sharp and other manufacturers . The system can be set up in the existing GSM network, the system providers can be less ex-situ transition, while the GSM system is quite popular in Asia for the acceptance of this new technology is expected to be quite high. Therefore, W-CDMA has inherent market advantage. The standard proposed GSM (2G)-GPRS-EDGE-WCDMA (3G) evolution strategy. GPRS is General Packet Radio Service (General Packet Radio Service) for short, EDGE is Enhanced Data rate for GSM Evolution (Enhanced Data Rates for GSM Evolution) short, these two technologies is called 2.5 generation mobile communication technology.

(2) CDMA2000


CDMA2000 is a narrow-band CDMA (CDMA IS95) broadband technology from CDMA technology, also known as CDMA Multi-Carrier, led by the North American companies made ​​Qualcomm, Motorola, Lucent, and later joined by South Korea's Samsung are involved, Korea now become the dominant standard. The system is derived from the narrowband digital standard out CDMAOne, the structure can be directly from the original CDMAOne upgrade to 3G, the construction cost. However, the area currently using CDMA only Japan, South Korea and North America, the CDMA2000, W-CDMA more than supporters. However, the development of CDMA2000 technology is currently the fastest progress in the standards, the first of many 3G phones have been available. The standard proposed from CDMA IS95 (2G)-CDMA20001x-CDMA20003x (3G) evolution strategy. CDMA20001x called 2.5 generation mobile communication technology. CDMA20003x and CDMA20001x The main difference is the application of multi-carrier technology, through the use of three carrier to bandwidth. China Unicom is currently using this program to 3G, and has built a CDMA IS95 networks.

(3) TD-SCDMA


Full-called Time Division - Synchronous CDMA (Time Division Synchronous CDMA), the standard is developed independently from China's 3G standard, June 29, 1999, the former Ministry of Posts and China Academy of Telecommunications Technology (Datang Telecom) proposed to the ITU . The smart wireless standard, synchronous CDMA, and software radio technology of today's leading international financial in which, in the spectrum efficiency, flexibility of business support, frequency, cost and other aspects of flexibility and unique advantages. In addition, because of the huge domestic market, the standard by all major telecom equipment vendors attention, more than half of the world of equipment manufacturers have announced to support TD-SCDMA standard. The proposed standard does not go through 2.5 generations of intermediate links, directly to 3G, GSM system is ideal for upgrading to 3G.

(4) WiMAX


WiMAX's full name is the Worldwide Interoperability for Microwave Access (Worldwide Interoperability for Microwave Access), also known as 802.16 wireless metropolitan area network, is another way for businesses and home users to provide "last mile" broadband wireless connectivity solutions. This technology and need to authorize or license-free after a combination of microwave devices, due to lower cost, will expand the broadband wireless market, enterprises and service providers to improve awareness. October 19, 2007, the International Telecommunication Union in Geneva in wireless communication plenary session, after the vote in most countries, WiMAX was approved officially become the WCDMA, CDMA2000 and TD-SCDMA after the fourth global 3G standard.

UMTS

UMTS is back in the early 1990s, the European Telecommunications Standards Institute (ETSI) began to seek technical solutions for the 3G standard. And ambitious system to 3G technology called UMTS (Universal Mobile Telecommunications System), which means Universal Mobile Telecommunications System. Wideband CDMA (bandwidth of 5MHz) proposal is one of its many options. Since then, Japan has greatly promoted the active participation of the 3G standard pace of globalization. In 1998, Japan and Europe in broadband CDMA proposed agreement on the key parameters, making it officially became the UMTS system in FDD (Frequency Division Duplex) frequency bands of the selected air interface technology solutions, and thus known as WCDMA. W that is broadband, as distinct from North America 's narrow-band CDMA (bandwidth 1.25MHz) standards.

The continued development of technical standards, embodied in the 3GPP UMTS standard four versions: R99, R4, R5, R6. The formation of a large and relatively independent of the internal standards. WCDMA is one of the earliest and the most perfect choice for air interface, and for Europe, Asia and the Americas, 3G operators are widely used.

3G era

Japanese mobile giant NTT DoCoMo was October 1, 2001 opening of the world's first 3G service, the service is based on WCDMA standard. Currently, the Asian region to become the fastest growing 3G, followed by Europe, followed by, the United States is not enthusiastic but as far behind in the technical preparation. In addition, quickest of Japan and South Korea , Thailand , Hong Kong has issued 3G licenses. Taiwan will grant 3G licenses work. Mainland is expected before the end of 2007 Expressed in 3G licenses, the market is expected to release two or three licenses.

Supplemental Type scheduling details:
NOKIA each series of each also has a regular:
Model is XX00, such as 3300,6600 and so on. These are very unique in the series, features a master models. 3300, is a clear positioning, a very attractive MP3 music phone. 6600 is a classic.
Model is XY00, such as 2100,3100,3200. These machines are the flagship model in the series. Nokia's first GSM clamshell 7200 is an example. Particularly among the more important models X100, X100 is positioned in its series where the main model. Observed that several sales of X100 will be able to see, this is true, X100 sales are a class of very stable, very good reputation models. They captured the market share of Nokia's main force.
Model is XY10, such as 3210,5510,7610,8810 and so on. The majority have a Nokia or a kind of innovative new features of the phone. For example, 3210 is Nokia's first mobile phone built-in antenna. Many new features and new ideas, that is, XY10 models show the world's first.
Model is XY20, such as 3120,3220,6820 and so on. These machines are generally based on its model number of the same XY location models based on complete and mature than the former models. For example 3120 is based on 3100,3220 3200.3120 inherited the 3100 performance, and replaced with a sense of silver chrome shell, called for young business people to use 3100.3220 3200 has the functions and features, such as inserts can Xpress , but also uses Nokia's first "flash the letter."
Model is XY30, basically before it XY00 in a sophisticated model summary. Such as 3230,6230,6630. In the non-smart phone in addition to the function screen 6230 is the strongest, the 6230 is definitely the 2004 6 Series strong in the market is a hot model. 3G mobile phone Nokia 6630 is one of the strongest, without exception, every configuration the forefront. The 3230 model has inherited the unique personality style 3 series, the added intelligence of the operating system it also allows 3-Series models feature enriched.
Model is XY40, the market is not that much, but not too successful.
Model is XY50, most are in their own series in a more powerful mobile phones, some smart phones. Such as the 7 Series in the noble 7250,7650, and 3650 3 series.
Model is XY60, most smart phones. For example 3660,6260.
Model is XY70, a new model suffix. Series models to its market segment with a supplement or a different interpretation of the other. Such as 6670 compared to 6630, features a slightly simplify the formation of another grade of choice. 7270 compared to 7200, to maintain the shape folding machine, improved screen, added some features, it is important to go retro 7270's shape is elegant fashion style rather than the 7200 style.
Model is XY80, if not remove the CDMA 2280 network, then it is a new model suffix.
Model is XYZ5, except 3355,8855 still 6255, but it is XYZ0 models use another version of the CDMA network. Example, relative to 3105 relative to the 3100,3125 3120,6225 compared to 6220. CDMA version of the functions normally and it will be a GSM version of the brothers a little bit different. For example 3100 is the 4 chord, and 3105 is 16 chords.
Model is XYZ8, and can be seen as a variant of its XYZ0 models. Such as 6108 compared to 3100 relative to the 6100,3108, prominent is this feature more than handwriting input, both the number 8 appears to be the end of the machine used specifically for Chinese handwriting input of Chinese characters designed and listed in the Chinese region. There is 1108 compared to 1100, the 1100 green white backlight replaced, as 1108.3128 is listed only in mainland China folding machine
Author: Lee Snow
Recently, Nokia issued a statement in a party: Nokia mobile phone ever named to four digits as the criteria in the last year have been a multimedia N series and E series of business after the machine began to change. Only now breaking the previous four-digit naming rules, the new naming convention above water.

Nokia original four-digit nomenclature, more and more phone models, models have become increasingly inadequate use has been inadequate, so must the development of a new nomenclature. Period in the four-digit model names, some of the more complex models is not easy to remember, but also lead to consumer confusion.
Nokia's early series entry-level 1, 2; 3 Series models for the play; 5 series sports series; 6 Series is excellent range of business machines; 7 series for the fashion series; 8 series is distinguished series; 9 series high smart phones.

Beginning this year, in addition to multimedia N series and E series of business solutions, the original four-digit series will re-integration, divided into Classic, Comfort, Contemporary, Expression, Active, Fashion, Premium seven categories, Classic classic Business Series, Comfort is the entry of low-level series, Contemporary replace the original Signature Series, Expression stress can have their own style, Active is a sports phone, Fashion is a fashion phone, Premium is replaced by distinguished series.
In addition to integrated four-digit model, the future will be in the model followed by the S, X, F, representing the slide machine, upright folding machine and plot three kinds of shape. The future will use the same model continues, the Contemporary Series as the model 6500, for example, possible future 6500S, 6500X, 6500F, or even 6500SA, 6500SB, 6500SC, will be followed by different letter in the model, and will not last order to go digital as 6501,6502,6503 and so on. Thus, while the Nokia 5500 model after the hang Sports, 5300 hang XpressMusic, Nokia 7370, after hanging LAmour.