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.