US wireless carriers

US has 5 major carriers AT&T Mobility, Sprint Corporation, T-Mobile US, and Verizon Wireless, as well as regional carrier US Cellular Corporation. Mobile virtual network operators (MVNOs) in the United States lease wireless telephone and data service from these major carriers.

For example,

• Google Fi leases T-Mobile, Sprint and US Cellular.
• China Telecom Americas (CTExcel) uses T-Mobile
• China Unicom Americas (CUniq) uses T-Mobile
• FreedomPop uses AT&T and Sprint
• KDDI Mobile uses AT&T
• NTT DoCoMo USA uses T-Mobile
• Straight Talk uses AT&T, Sprint, T-Mobile, Verizon
• Walmart Family Mobile uses T-Mobile
• Xfinity Mobile uses Verizon
• TracFone leases AT&T, T-Mobile, U.S. Cellular (feature phones only), Verizon

There are some other brands are subsidiaries of these top carriers. For example,  

• Cricket Wireless LLC is a prepaid wireless service provider in the United States, a wholly owned subsidiary of AT&T Inc. It offers mobile voice, text, and data using parent AT&T's nationwide network. 
• Metro by T-Mobile (formerly known as MetroPCS, stylized as metroPCS) is a prepaid wireless carrier brand owned by T-Mobile US. 
• Sprint Includes Boost Mobile and Virgin Mobile USA.