Beyond 3G
In telecommunications, 4G is the fourth generation of mobile phone mobile communication technology standards. It is a successor of the third generation (3G) standards. A 4G system provides mobile ultra-broadband Internet access, for example to laptops with USB wireless modems, to smartphones, and to other mobile devices. Conceivable applications include amended mobile web access, IP telephony, gaming services, high-definition mobile TV, video conferencing, 3D television and Cloud Computing.
Two 4G candidate systems are commercially deployed: the Mobile WiMAX standard (at first in South Korea in 2006), and the first-release Long Term Evolution (LTE) standard (in Oslo, Norway since 2009). It has however been debated if these first-release versions should be considered to be 4G or not, as discussed in the technical definition section below.
In the U.S., Sprint Nextel has deployed Mobile WiMAX networks since 2008, and MetroPCS was the first operator to offer LTE service in 2010. USB wireless modems have been available since the start, while WiMAX smartphones have been available since 2010, and LTE smartphones since 2011. Equipment made for different continents are not always compatible, because of different frequency bands. Mobile WiMAX are currently (April 2012) not available for the European market.
Read more about Beyond 3G: Technical Definition, Background, IMT-Advanced Requirements, Data Rate Comparison, History of 4G and Pre-4G Technologies, Beyond 4G Research