Mobile service provider
A mobile service provider (MSP) is a company that offers transmission services to users of wireless devices (smartphones and tablet PCs) through radio frequency (RF) signals rather than through end-to-end wire communication.
The major mobile service providers in the United States include Verizon Wireless, Sprint, AT&T and T-Mobile. Their services differ in terms of the wireless service plans, data speeds (3G vs. 4G), reliability and the devices they support.
A mobile service provider is sometimes called a wireless service provider (WSP), wireless carrier or mobile carrier.