Definition of 3G in English:

3G

noun

  • [mass noun] A mobile communications standard that allows mobile phones, computers, and other portable electronic devices to access the Internet wirelessly.

    ‘with 3G allowing us to send much bigger files to handsets, video content is the big area that's poised for take-off’
    [as modifier] ‘a 3G network’

Origin

1990s: abbreviation of third generation.