5G is the fifth generation of mobile communication networks. Most consumers now use 3G or 4G/LTE networks, which were introduced to the public in 2001 and 2009, respectively. AT&T shuttered its 2G system in early 2017. Verizon, T-Mobile, and Sprint have said they’ll continue to operate their 2G networks through 2019, 2020, and 2021, respectively. It is anticipated that 5G systems will use existing cell towers and small cells.