4G

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4G.JPEG

4G (第四代移动通信技术) is the fourth generation of mobile communications technology featuring the 3G and WLAN technologies that enables the transmission of high-quality video images as displayed on a high-definition television.

The 4G system supports download speeds of up to 100Mbps -- roughly 2,000 times faster than that of the current dial-up networking -- and upload speeds of 20 Mbps, fulfilling nearly all user needs in terms of wireless services.

Moreover, the 4G network can be deployed in areas where DSL and cable modems are not covered and can then be further extended to the whole region.

Conceivable applications include amended mobile web access, IP telephony, gaming services, high-definition mobile TV, video conferencing, 3D television and cloud computing.

4G standards

LTE

Long Term Evolution (LTE) is the evolution of 3G technology. It improves radio interface and introduces OFDM and MIMO as the only standard of its wireless networking evolution. LTE has a theoretical net bit rate capacity of up to 100 Mbps in the downlink and 50 Mbps in the uplink if a 20 MHz channel is used -- and more if multiple-input/multiple-output (MIMO) are used.

LTE-Advanced

LTE Advanced (Long Term Evolution Advanced) is essentially an enhancement to LTE. It is not a new technology, but rather an improvement on the existing LTE network. This upgrade path makes it more cost effective for vendors to offer LTE and then upgrade to LTE Advanced which is similar to the upgrade from WCDMA to HSPA.

WiMax or IEEE 802.16

WiMax (Worldwide Interoperability for Microwave Access) or IEEE 802.16 is the earliest 4G standard appearing around 2000. It provides up to 70M of Internet access rate, 30 times that provided by 3G technology. Wimax has about 8 million users worldwide, with 60 percent of that number based in the U.S.

Wireless MAN-Advanced or IEEE 802.16m

Wireless MAN or IEEE 802.16m is the upgrade of WiMax currently under development, with the objective to fulfill the IMT-Advanced criteria of 1 Gbps for stationary reception and 100 Mbps for mobile reception.

International standards

On January 18, 2012, the International Telecommunications Union approved LTE-Advanced and WirelessMAN-Advanced (802.16m) technologies as international 4G standards at the plenary session of the Radio Communication Conference. In doing so, China’s homegrown TD-LTE-Advanced and FDD-LTE-Advance become the international 4G standards.

4G license in China

On December 4, 2013, the Ministry of Industry and Information Technology (MIIT) issued 4G licenses to China Mobile, China Telecom and China Unicom in order to provide users 20 to 50 times faster mobile Internet access compared with the current 3G network, and create a new trillion-yuan market for device and service upgrade, marking the beginning of a new era in China's high-speed mobile network.

The three Chinese telecom operators received permits to offer 4G mobile network services employing homegrown TD-LTE technology.

The ministry did not issue the more international FDD-LTE license this time, but said it would test the converged TD-LTE/LTE FDD network in the future.

The 4G technology will lower bandwidth costs and promise faster mobile broadband. Users across Beijing, Guangzhou and Chongqing will be the first to enjoy commercial 4G services. Shanghai, still building a citywide 4G network, will launch the services later. China Mobile said the rates for 4G services will be cheaper than those for 3G. In a number of cities, where the company has launched the 4G network for trial commercial use, the tariff is 20 percent less than similar 3G network plans.

Li Yue, president of China Mobile, said the price of 4G smartphones will decline rapidly following the approval of the 4G network for commercial use.

Now only a number of smartphone models in China are equipped with modules that support home-grown 4G TD-LTE technology, with prices ranging from 350 US$350 to US$800.

China is the major promoter of the TD-LTE standard as well as a major owner of the standard core patents. LTE FDD is the other international 4G standard and is popular in Europe.

MIIT said the convergence of the two standards is gaining momentum in the global telecom industry. A total of 10 converged TD-LTE/LTE FDD commercial networks have thus far been established worldwide.