What is 4G high-speed Internet access?

The main advantages of 4G If 2G and 3G communication are insignificant for the development of human informatization, then the future 4G communication will give people real freedom of communication and completely change people's lifestyle and even social form. In 2009, the envisaged 4G communication has the following characteristics: the communication speed is faster. Because the original purpose of people's research on 4G communication is to improve the wireless access speed of mobile devices such as mobile phones to the Internet, the most impressive feature of 4G communication is the faster wireless communication speed. Compared with the data transmission rate of mobile communication system, the first generation analog only provides voice service; The transmission rate of the second generation algebraic bit mobile communication system is only 9.6Kbps, and the highest can reach 32Kbps, such as PHS; ; The data transmission rate of the third generation mobile communication system can reach 2 Mbps predicted by experts, and the fourth generation mobile communication system can reach 10Mbps to 20Mbps, and even the highest speed can reach 100Mbps to transmit wireless information, which will be equivalent to about 100 times of the latest mobile phone transmission speed in 2009. Broader network spectrum In order to make the transmission of 4G communication reach 100Mbps, communication operators must carry out substantial transformation and research on the basis of 3G communication network, so that the communication bandwidth of 4G network is much higher than that of cellular system of 3G network. According to AT & amp； T executives said that each 4G channel is expected to occupy 100MHz spectrum, which is 20 times that of W-CDMA3G network. Communication is more flexible. Strictly speaking, the function of 4G mobile phone can no longer be simply classified as "telephone". After all, the transmission of voice data is only one of the functions of the 4G mobile phone, so the 4G mobile phone should be regarded as a small computer in the future. Moreover, there will be a more amazing breakthrough in the appearance and style of 4G mobile phones. People can imagine that glasses, watches, cosmetic boxes and travel shoes can all be used under the premise of convenience and individuality. In the future, 4G communication will not only enable people to communicate anytime and anywhere, but also download and transmit data, pictures and videos in both directions, and of course, play online games with strangers they have never met. There may be the distress of being locked by the online positioning system forever, but compared with the convenience and security brought by the map it provides, this is insignificant. The fourth generation of mobile communication is more intelligent, which is not only reflected in the intelligent design and operation of terminal equipment of 4G communication, such as the dependence on menu and scrolling operation will be greatly reduced, but more importantly, 4G mobile phones can realize many unimaginable functions. For example, a 4G mobile phone can set factors according to the environment, time and so on to remind the owner of the mobile phone what to do and what not to do at this time. The 4G mobile phone can directly download the box office information of the cinema to PDA, which can clearly display the ticket sales and seats, and everyone can buy their own satisfactory movie tickets online according to this information. 4G mobile phone can be regarded as a portable TV, which is used to watch various live broadcasts such as sports competitions.

4G technical standards are compared with 20 12. 1.20 ITU's 4G (IMT-Advanced) standard: LTE-Advanced:LTE (Long Term Evolution) follow-up research standard; Wireless metropolitan area network (802.16m): the follow-up research standard of WiMAX. TD-LTE is selected as one of the branches of LTE-Advanced standard. This is mainly put forward by our country. LTE LTE Long Term Evolution) project is the evolution of 3G, which improves and strengthens the air access technology of 3G, and adopts OFDM and MIMO as the only standards for its wireless network evolution. Its main feature is that it can provide the peak rate of downlink 100Mbit/s and uplink/50Mbit/s under the spectrum bandwidth of 20MHz, which greatly improves the capacity of the cell and greatly reduces the network delay: the internal one-way transmission delay is less than 5ms, the transition time of the control plane from sleep state to active state is less than 50ms, and the transition time from resident state to active state is less than100 ms. Its evolution history is as follows: GSM->; GPRS-& gt； Edge->; WCDMA-& gt； HSDPA/HSUPA->； HSDPA+/HSUPA+-& gt； Long-term evolution of FDD-LTE GSM: 9K->; GPRS:42K-& gt； EDGE: 172k->； WCDMA:364k-& gt； Hsdpa/hsupa:14.4m->; HSDPA+/HSUPA+:42M-& gt； FDD-LTE:300M, as an upgraded version of WCDMA networks HSPA and HSPA+, can evolve to FDD-LTE, including China's own TD-SCDMA network, which will bypass HSPA and directly evolve to TD-LTE. This 4G standard has won the greatest support and will be the mainstream of future 4G standards. The network provides the network speed comparable to fixed broadband and the switching speed of mobile network, and the network browsing speed is greatly improved. At present, LTE terminal equipment has the disadvantages of too much power consumption and high price. According to Moore's Law, it is estimated that it will take at least 6 years to reach the current mass production cost of 3G terminals. LTE-Advanced LTE-Advanced: Literally, LTE-Advanced is an upgraded version of LTE technology, so why can both standards become 4G standards? The official name of LTE-Advanced is the further development of E-UTRA, which conforms to the requirements of ITU-R for IMT-Advanced technology set and is an important source for 3GPP to form the European IMT-Advanced technology proposal. LTE-Advanced is a backward compatible technology, fully compatible with LTE, and it is an evolution rather than a revolution, which is equivalent to the relationship between HSPA and WCDMA. The relevant characteristics of LTE-Advanced are as follows: bandwidth: 100MHz peak rate: downlink 1Gbps, uplink 500Mbps peak spectrum efficiency: downlink 30bps/Hz, uplink 15bps/Hz. For indoor environment optimization, it effectively supports new frequency band and large bandwidth applications, and the peak rate is greatly improved, and the spectrum efficiency is limited. Strictly speaking, LTE is a 3.9G mobile Internet technology. The shortlist of LTE-Advanced includes TDD and FDD, among which TD-SCDMA will be able to evolve to TDD and WCDMA will evolve to FDD. Mobile-dominated TD-SCDMA network expects to bypass HSPA+ network directly and enter LTE directly. WiMAX WiMAX: WiMAX (Worldwide Interoperability for Microwave Access), that is, global microwave interconnection access. Another name for WiMAX is IEEE 802 438+06. The technical starting point of WiMax is relatively high. The highest access speed that WiMAX can provide is 70M, which is 30 times of the broadband speed that 3G can provide. For wireless networks, this is indeed an amazing progress. WiMAX will gradually realize the mobileization of broadband services, while 3G will realize the broadband of mobile services, and the degree of integration of the two networks will be higher and higher, which is also the integration trend of the mobile world and fixed networks in the future. 802. 16 works in the unlicensed frequency band from 2GHz to 66GHz, while 802. 16a is a broadband wireless access system using the unlicensed frequency band from 2G to 1 1GHz, and its channel bandwidth can be adjusted in the range of 1.5M to 20MHz as required, so it is in the range of. Therefore, the spectrum used by 802. 16 may be richer than any other wireless technology, and WiMax has the following advantages: (1) For known interference, narrow channel bandwidth is beneficial to avoiding interference and saving spectrum resources. (2) Flexible bandwidth adjustment ability is beneficial for operators or users to coordinate spectrum resources. (3) 3) The wireless signal transmission distance of 50 kilometers that 3)3)WiMax can reach is incomparable to WLAN, and the network coverage area is 10 times that of 3G iron tower. As long as a few base stations are built, the coverage of the whole city can be realized, and the coverage area of wireless networks can be greatly improved. However, WiMax network has great advantages in network coverage and network bandwidth, but its mobility has inherent defects, which can not meet the seamless link of the network at high speed (⊙50k m/h). In this sense, WiMax can't reach the level of 3G network. Strictly speaking, it is not a mobile communication technology, but only a wireless LAN technology. The hope of WiMax lies in IEEE 802. 1 1m technology, which will effectively solve these problems. Thanks to the active participation of China Mobile, Intel and Sprint, WiMax has become a 4G network mobile phone with voice second only to LTE. About the technology of IEEE 802. 16m, we will leave it in detail at the end. Wimax currently has about 8 million users worldwide, 60% of whom are in the United States. Wimax is actually the earliest 4G communication standard, which appeared around 2000. Wireless Man Wireless Man-Advanced: Wireless Man-Advanced is actually an upgraded version of WiMax, which is the IEEE 802. 16m standard. 802. 16 series standard is officially called wireless metropolitan area network in IEEE, and the advanced version of wireless metropolitan area network is IEEE 802.5438+06m. Among them, 802. 16m can provide the highest wireless transmission rate of 1Gbps, and will be compatible with future 4G wireless networks. 802. 16m can provide 1Gbps downlink rate in roaming mode or high efficiency/strong signal mode. The standard also supports "high mobility" mode, which can provide 1Gbps rate. Its advantages are as follows: 1. Improve network coverage and rebuild link budget; 2. Improve spectrum efficiency; 3. Improve data and VOIP capabilities; 4. Low latency &; QoS enhancement; 5. save electricity; At present, WirelessMAN-Advanced has five network data specifications, including extremely low data rate 16kbps, low data rate and low-speed multimedia 144kbps, medium-speed multimedia 2Mbps, high-speed multimedia 30Mbps and ultra-high-speed multimedia 30 Mbps- 1 Gbps. However, the standard may be first adopted by the military. IEEE said that military intervention will accelerate the maturity and perfection of wireless metropolitan area network, and today's military is tomorrow's civilian use. In any case, it is very likely that WirelessMAN- Advanced will be recognized by ITU as a 4G standard.