A somewhat vague term used to describe wireless mobile radio technologies that offer faster data rates than 3G (third generation) technologies.
The most common technology recognized worldwide as 4G is LTE.
4G networks are also more data-centric and based on standard Internet technologies such as IP. Voice service, if provided over the 4G network, is typically provided using a special form of VoIP called VoLTE.
Some carriers — including T-Mobile and AT&T — once used the term "4G" to refer to upgraded 3G networks that provide near-4G data speeds even they are based on 3G technology. HSPA+ technology is the 3G upgrade that enables these faster speeds.