4G

4G communication at 100 Mbit/s while moving, and 1 Gbit/s while stationary.

Pervasive networks

• simultaneously connected to several wireless access technologies (Wi-Fi, UMTS for example) and can seamlessly move between them (handover)
  
• smart-radio aka cognitive radio technology to efficiently manage spectrum use and transmission power
• mesh routing protocols
• 4G may use OFDM , and also OFDMA.
• packet switching only

In general, a generation is defined by the result of technology changes over a 10-15 year time frame. Thus, 4G would refer to whatever is deployed in the 2010-2015 period, assuming 3G deployment spans the 2000-2009 period.

See Wikipedia 4G