Mexico has one or more cellphone service providers and companies. A Cell phone, also known as a mobile phone, or simply a mobile is a device that can make and recieve calls over a large area without wires, by using radio signals. One can also use it for texting and data tranfer of various kinds (including using the internet, now). It has revolutionized the field of communication in the past few decades. Cell phone penetration is very high in this country, and a number of providers are available. They can use either GSM or CDMA technology for providing the service. The top service providers in America, one ore more of which are present in Mexico include Verizon Wireless, AT&T Mobility, Sprint Nextel, T-Mobile USA, TracFone Wireless, MetroPCS, U.S. Cellular and Cricket Wireless. Smaller providers give regional coverage, and national services are enabled by roaming agreement with the bigger companies.