5G is hitting the mainstream fast: According to a GSA report, 58 countries had 5G networks as of June 2021 , up from 38 about a year ago. A dozen more have had 5G mobile technology deployed in part. It is in fact expected that 5G will reach 1 billion users in 3.5 years, compared with 4 years for 4G and 12 years for 3G.