"3G" is simply a generic term indicating the “third generation” of standards for mobile networking. Mobile broadband users typically see internet speeds of approximately 600-1400kbps download (with bursts up to 2,000 kbps) and 500-800kbps upload where 3G coverage is available. "4G" is the fourth generation of cell phone mobile communications 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 mobile web access, IP telephony, gaming services, HD TV, video conferencing and 3D TV. Peak speed requirements for 4G service is set at 100 megabit per second (Mbit/s) for high mobility communication (such as from trains and cars) and 1 gigabit per second (Gbit/s) for low mobility communication (such as pedestrians and stationary users). As opposed to earlier generations, a 4G system does not support traditional circuit-switched telephony service, but all Internet protocol (IP) based communication such as IP telephony.
