What is the Difference between 4G and 4G LTE

Current LTE and WiMAX implementations are often cited in the marketplace as 4G, although they don't fully comply with the planned requirements of 1 Gbps for stationary reception and 100 Mbps for mobile. The common argument for branding LTE and WiMAX systems as 4G is that they use different frequency bands to 3G technologies; that they are based on a new radio-interface paradigm; and that the standards are not backwards compatible with 3G, while some of the standards are expected to be forwards compatible with "real" 4G technologies.  


  
LTE or LTE Advanced or 4G LTE are also Referred to as 4G technologies as they have the same standards that are compatible with 4G technologies. 4G technology has a max download speed of 1 Gbps which has not yet been implemented.

Given in simple words

LTE = Not 4G

Technically LTE is 3.9G as it uses technology that is compatible with forward and backward generations of technology which is usually Referred t as 4G LTE

Speeds of Different Technologies

2G - 14.4 Kbps

3G - 14.4 Mbps

LTE - 115 Mbps ( Currently being deployed )

4G - 1 Gbps ( Will be Deployed in Near Future)