4G

"4G" is the fourth generation mobile communication and technical abbreviation, is the collection of 3G wireless local-area network (WLAN) at an organic whole with high quality video and able to transmit images and image transmission quality and high definition TV neck-and-neck technical products. 4G system can 100Mbps speed to download, dial-up Internet faster than 2000 times, upload speed also can achieve 20Mbps, and satisfies almost all users for wireless service requirements. And in user the most attention, and fixed price 4G neck-and-neck in price, broadband networks, and billing way more flexible, users can completely according to their own needs to determine the services. In addition, 4G can in DSL and cable modem not covered place deployment, and then extended to the whole region. Obviously, 4G has incomparable advantages.

The background of the development of 4G

Communication technology is developing rapidly, give people a lot of enjoyment. With the data communication and multimedia services

Demand of development to adapt to the mobile data, mobile computing and mobile multimedia operation requires the fourth generation mobile communication began to rise, so have reason to expect the fourth generation mobile communication technology gives people a more beautiful future.

All technology development cannot be achieved overnight, from GSM, GPRS to 4th generation, need continuous evolution, and these technologies can coexist. People knows the earliest mobile phone use analogue cellular communication technology that can only provide regional speech business, and call effect is poor, confidentiality, user's performance is bad also to answer the scope is limited. Along with the rapid development of mobile phone users is growing rapidly, the traditional communication mode cannot have satisfied the demand for people to communicate, below this kind of circumstance appear GSM technologies, this technology is used in a TDMA, allowing narrowband radio frequency (namely "honeycomb ') simultaneously group 8 calls. It is based on European standards and determine the range of frequencies in 900 ~ 1800MHz between digital mobile phone system, frequency for 1800MHz system is also American adopted. GSM is 1991 came into use. By the end of 1997, has been operating in more than 100 countries, become the European and Asian actually standards. GSM digital network also have strong confidentiality and anti-jamming and timbre is clear, stable, and with the call of large capacity, high frequency resource utilization, interface open, powerful, etc. But it can provide data transfer rate of only 9.6 kbit/s, and five or six years ago with a fixed telephone dial-up speeds, when the Internet almost provide only pure text information. And nowadays are popular digital mobile phone is the second generation (2G), generally USES the GSM and CDMA technology. Second-generation mobile phone besides can provide the so-called "global" voice business outside, already can provide low-speed data business, which is also transceiver short message, and so on. Although theoretically, 2gb mobile phone users worldwide can undertake mobile communications, but without the united international standard, all kinds of mobile communication system each other mutually exclusive, users of mobile phones to bring a lot of inconvenience.

Aiming at the defects, GSM people in 2000 and launched a new communications technologies GPRS, this technology is in GSM based on an interim technology. GPRS launch marks the people in the history of the GSM made the most significant step, GPRS in mobile users and data networks provide a link between mobile users, to provide high-speed wireless IP and x.25 packet data access service.

After this, communication operators and its EDGE technology, this kind of communication between the existing technology is a kind of the second generation of mobile network and the third generation mobile network the transition between the technology, therefore also have people call it "second-generation half" technology, it improves the efficiency of high-speed GPRS channel coding standard, it allows mobile data as 384KbPs data transfer rate, can fully satisfy the future wireless multimedia applications of bandwidth needs. EDGE provides a from GPRS to the third generation mobile communication interim scheme, thus make the existing network operators can maximize existing wireless network equipment, in the third generation mobile network commercialization in advance in order to provide users before personal multimedia communication business.

In emerging communications technology continuously push, a symbol of 3G communication under the symbol technology WCDMA may also become the mainstream of the future communication technology. This technology has brought for the users supreme 2Mbit/s data transfer rate, in such conditions, computer application in any media can pass the wireless network easily transfer. WCDMA through effective by using passcal, not only can smooth processing sound, image data, and Internet quick connection, Besides WCDMA and mpeg-4 technology combine can deal with real dynamic image. Communication between people the bottleneck of by the network transmission rate will be transformed into a new range of applications of the wireless network provide: how to make better serving people rather than people brings harassment, how to let everybody can from the sea of information quickly get the information they need, how can easily carry, use various terminal equipment, various terminal equipment between how better automatic collaborative work, etc. In the above communication technology based on wireless communication technology could eventually towards 4G communication technology era.

From wireless communication system development course view, the first generation of mobile communication system of task has been reached, but now is the second generation mobile communication system of times over the next ten 3G mobile communication system convention is the period, perhaps zhengxing came after ten years will be the fourth generation mobile communication of the world. But it is not difficult to find every different mobile communication system which would have repeatability of time points, about every ten years have an update technology, but with the ever-changing of telecommunication technology, perhaps change will be faster and more time will also be short. For mobile communication service providers, equipment supplier or other relevant industries, it must watch mobile communication technology changes to meet the market demand.

The concept of 4G introduction

In 3G communication technology is in the womb of time, higher technology application has been made in the laboratory research and development. So in people expect the third generation mobile communication system brought about by the high quality services at the same time, the fourth generation mobile communication system of the latest technology is also in the laboratory quietly underway. What is "4G" communication?

Until 2009 people still unable to 4G communication were precisely define, someone says the concept of 4G communication from other wireless service technology, from the wireless application protocol, global compact wireless services to 3G, Someone said "4G" communication is a beyond 2010 outside the research topic, 4G communications is system of system, can use all sorts of different wireless technology, But no matter how people of 4G communication defined, a little people can affirm is 4G communication is probably a more perfect than 3G wireless communication of the new world, it creates a lot of consumer mind-boggling applications. 4G maximum data transfer rate more than 100Mbit/s, this rate is mobile phone data transfer rate 10,000 times, but also 3G mobile phone rate of 50 times. 4G mobile phones can provide high performance of the confluence of media content, and through the ID application is a personal identity identification equipment. It can also accept high resolution movies and TV programs, thus become a merger radio and communication of new infrastructure of a link. In addition, 4G wireless instant connection, etc will cost some service than 3G cheap. Also, is expected to integrate different patterns of 4G wireless communication - from the wireless local area network and bluetooth such indoor network, cellular signal, broadcasting television to satellite communications, mobile users can roam freely from a standard to another standards.

4G communication technology didn't break away from previous communications technology, but with traditional communication technology as the foundation, and using some new communications technologies, to continuously improve wireless communication network efficiency and functional. If the 3G for people to provide a high-speed transmission wireless communication environment, then the 4G communication will be a super-fast wireless network, a kind not to need cable of the information superhighway, this new network can make telephone users to wireless and 3d virtual reality attachment.

Compared with the traditional communication technique of 4G communication technology, the most obvious advantage lies in conversation quality and data communications speed. However, in sound quality, mobile phone consumer still can accept it. With the development of technology and application and existing mobile-phone networks in mobile phone call quality is still in further improved. Data communication speed fast pace is indeed a great advantages, its maximum data rate reached 100Mbit/s, it is incredible things. Plus, because of technical sophistication ensures that the cost of investment, the future of 4G greatly reduce communication costs than 2009 communication cost is low.

4G communication technology is the third generation later again wireless communication technology development, and its development and more have clear objectives: to improve mobile device wireless access Internet speed - according to the 3G mobile market by three stages of development plan, go 3G multimedia services after 10 years into the third stage of development, then cover the global 3G network has been basically completed more than 25%, the global population use the third generation mobile communication system. In developed countries, 3G service the prevalence rate of more than 60%, then there has to be updated generation system to further enhance the quality of service.

In order to make full use of 4G communication provides people with advanced service, people also must have the aid of all kinds of 4G terminal can realize, and quite a few communication operators is see future communication the huge potential market, they have begun to look aim for the production of 4G communications terminal product, such as production with high-speed packet communications functions of small terminal, production of corresponding with a camera and film and television videophone images sending service terminals, or production and computer matching KaShi data communication special terminal. With these communications terminal, people of cell phone users can follow one's inclinations of roaming, at any time and place to enjoy high quality communication.

4G system network structure and key technologies

4G mobile system network structure can be divided into three layers: the physical network layer, middle layer, network layer and application environment. Physical network layer provides access and routing function, which by wireless and core network combination format completed. Among the function of environmental layer has authored QoS mapping, address transform and complete management etc. Physical network layer and middle layers and their application environment environment of the interface between is open, it makes the developing and providing new applications and services made easier, provide seamless high data rate of wireless services and runs on multiple frequency band. This service can adaptive multiple wireless standards and multi-mode terminals ability, across multiple operators and service, offering a wide range of service. The fourth generation mobile communication system of key technologies, including channel transmission; Robust of high-speed access technology, modulation, and information transmission technology, High-performance, miniaturization and low cost adaptive array of smart antenna, Large capacity, low cost of wireless interface and optical interface; System management resources; Software radio, network structure agreement. The fourth generation mobile communication system is mainly by orthogonal frequency division multiplexing (OFDM) as core technology. OFDM technology is characteristic of network structure highly extensible, has the good anti-noise performance and anti multichannel interference ability, can provide wireless data technology quality high rate, time delay higher (small) services and better performance to price, we can provide better scheme 4G wireless networks. Such as wireless regional loop (WLL), digital audio broadcast (DAB) etc, expected are adopted the OFDM technology. To accelerate growth 4G mobile communications wide belt wireless connections requirements providing technical response, the crossing of the public and dedicated, indoor and outdoor various wireless systems and network ensure provide seamless service. Through to the most suitable available network provides users demand, can deal with best service based on Internet communications expected growth, add new frequency spectrum resources, make large expansion, provide different types of communication interface, using routing technology mainly of network structure, with FuLi leaf transform to develop hardware architecture realize fourth-generation network architecture. Mobile communications will to digital, fast pace, broadband melt, the higher frequencies of direction, mobile data, mobile IP is expected to become the future YiDongWang mainstream business.

The main advantages of 4G

If 2gb, 3G communication for the human the development of informationization is trivial, then the future 4G communication gave people the real communication freely, and thoroughly change people's life style and even the social form. 2009 in conception of 4G communication has the following features:

1, communications speed is faster

Because people study 4G communication original purpose is to enhance cellular phones and other mobile devices wireless access the Internet rate, therefore 4G communication to the person most impressive faster than it has characteristics of wireless communication speed. From mobile communication system data transfer rate comparisons, the first generation of analog only provide voice services; The second generation digital type of mobile communication system transmission rate also only 9.6 Kbps and tiptop 32Kbps, such as PHS; And the third generation mobile communication system data transfer rate can reach 2Mbps; Experts estimate that the fourth generation mobile communication system can achieve 10Mbps to 20Mbps, it could be as high as per second 100Mbps speed transmission wireless information, this kind of speed will be equivalent to 2009 latest mobile transmission speeds of 10,000 times or so.

2, network more wide spectrum

Want to make 100Mbps 4G communication to the transmission, communication operators must in 3G communication network on the basis of greatly and transformation of research, in order to make 4G network in communication bandwidth than 3G network cell system bandwidth much higher. According to research 4G communication AT&T executives said, estimates that each will occupy 100MHz 4G channel of spectrum, equivalent to 3G networks CDMA W - 20 times.

3, communication more flexible

In the strict sense, the function of 4G mobile phones, already cannot simple danzhou-tunchang "telephone" category, after all voice data transmission is just one of the functions of 4G mobile phone, so it should be more mobile phone future 4G calculate going up is a small computer and mobile phone from appearance and style 4G, there will be even more spectacular breakthrough, people can imagine, glasses, watches, cosmetic box, shoe, with convenient and individual character for the premise, any one can see objects are likely to become 4G terminal, but people still don't know how should call it that. The future of 4G communications make people not only can at any time anywhere communication, can more two-way transfer data, drawings, download images, of course, more can and have never met strangers online on-line kumite game. Maybe there was nowhere to online positioning system forever locked DunXing upset, but with it which provides the convenience of the map and safety compared, this is negligible.

4, intelligent performance is higher

The fourth generation mobile communication of higher intelligence, not only express in 4G communications terminal equipment design and operation features intelligence, for example of a menu and rolling operation dependence will reduce greatly, more important 4G mobile phones can realize many unimaginable function. For example 4G phones can according to the environment, setting time and other factors to timely remind mobile phone owners while the doing what, or what not to do things, mobile phones can put the cinema 4G box-office material, direct download to PDA, these material to the above situation, seating tickets show clearly, everybody can according to the information for the movie tickets online purchase its own satisfaction, 4G mobile phones can be regarded as a mobile TV, sports like for you to see various live.

5, compatibility smoother

To make as soon as possible by the people to accept the 4G communications, not only consider its powerful outside, still should consider to existing communication foundation, in order to let more current telecommunication users in the least investment circumstances can easily transition to 4G communications. Therefore, from this perspective, the future of the fourth generation mobile communication system shall meet the global roaming, interface with various open, can network connections, terminal diversified and smooth transition from the second generation etc.

6, provide various value-added services

4G communication wasn't from the basis of 3G communication through simple upgrade and the evolution over, their core construction technology is fundamentally different, 3G mobile communication system is mainly by CDMA as the core technology, while 4G mobile communication system technology criterion with orthogonal multitasking separate frequency technology (OFDM) the most-watched, using this technology, people can realize regional loop (such as wireless WLL), digital audio broadcast (DAB) wireless communication proliferation services; But considering and 3G communication of transition, the fourth generation mobile communication system not only in the future by OFDM a technique, CDMA techniques will be in the fourth generation mobile communication system, and OFDM technology mutual cooperate to play a bigger role, even the future of the fourth generation mobile communication system will have new integration technology such as OFDM/CDMA produced, the above mentioned digital audio broadcast, actually it utilizes truly technology is the integration of technology FDMA OFDM /, also is to use two kinds of combination of techniques. Therefore the future to OFDM as the core technology of the fourth generation mobile communication system, also can combine two technical advantages, part was the extending techniques. CDMA

7 and achieve higher quality of multimedia communication

Although the third generation mobile communication system also can realize various multimedia communication, but in the future of 4G communication can satisfy the third generation mobile communication is still cannot achieve in coverage, communication quality, cost support high-speed data and high-resolution multimedia services needs, the fourth generation mobile communication system offers wireless multimedia communication services including voice, data, video and other large quantities of information through broadband channel transmitted, therefore the future of the fourth generation mobile communication system is also called "multimedia mobile communication". The fourth generation mobile communication is not only to cope with the number of users increase, more important is, must respond to multimedia transmission requirements, of course also includes communication quality requirements. In summary, must first can accommodate market is huge number of subscribers, improving existing communications of poor quality and achieve high speed data transmission requirements.

8, frequency use efficiency is higher

Compared with the third generation mobile communication technology for the fourth generation mobile communication technology in the development process of use and introducing many powerful disruptive technology, such as some optical fiber communication products company to further enhance the wireless Internet backbone bandwidth width, introduced exchange level technology that could also covers different types of communication interface, i.e. the fourth generation is mainly use Routing technology (ccna) mainly network architecture. Because of using several different technology, so the use of radio frequency than the second and third generation system is more effective. Under the most optimistic estimates, the effectiveness of can let more people use same quantity of radio spectrum to do more things, and do these things when it goes really fast. The researchers said, the download speed more likely to achieve 5Mbps to 10Mbps.

9 and communication costs more cheaply

Because of 4G communication not only solves the compatibility issue with 3G communication, let more existing communications users can easily upgrade to 4G communication, and communication 4G introduced many cutting-edge communication technology, the technical guarantee 4G communication can provide a flexibility very high system operating mode, so relative to other technologies, it 4G communication deployment more easily more rapidly, At the same time in the construction of 4G communication network system, communication operation traders would consider directly in 3G communication network infrastructure above, use introduced gradually method, so that you can effectively reduce the operation cost and users. According to researchers said, "4G" communication wireless real-time service fee will be some links than 3G communication more cheaply.