3G systems are the latest development of wireless communications technology that offer faster communications services.

Significant features of 3G systems are:
· Use packet-switching technology that support higher data transmission rates and increased capacity, which suitable for high-speed data applications and traditional voice calls.
· New features such as TV streaming, multimedia, video conferencing, Web browsing, e-mail, paging, fax, and navigational map, anytime anywhere with seamless global roaming. 

The meaning of 3G has been standardized in the IMT-2000 standardization process. It has opened the way to enabling innovative applications and services, such as multimedia entertainment, infotainment and location-based services. This process did not standardize on a technology, but rather on a set of requirements, for example 2 Mbit/s maximum data rate indoors, 384 kbit/s outdoors.

3G mobile phone systems such as UMTS and CDMA2000 1xEV-DO have begun to be publicly available at the beginning of the 21st century.

Japan was the first country to introduce a 3G system.