Telcel:Telcel is a Mexican wireless telecommunications company, owned by América Móvil. Founded in 1989 and based in Mexico City, Telcel is the leading provider of wireless communications services in Mexico. As of December 31, 2006, Telcel’s cellular network covered more than 63% of the geographical area of Mexico, including all major cities, and 90% of Mexico’s population. Telcel holds concessions to operate a wireless network in all nine geographic regions in Mexico using both the 850 megahertz and 1900 megahertz radio spectrum. According to Cofetel (Comision Federal de Telecomunicaciones—Mexico’s Federal Telecommunications Commission), as of July 2008, Telcel’s subscribers represented an estimated 77.2% share of the Mexican wireless market. On August 2011, Telcel reported it has 66.9 million cellular subscribers.D-AMPS,GSM-1900 MHz (GPRS, EDGE),850/1900 MHz UMTS, HSDPA,HSPA+,1700 MHz LTE.
Movistar: Movistar is the major Spanish mobile phone operator owned by Telefónica S.A. operating in Spain and in many Latin American countries. It is the largest carrier in Spain with 22 million customers (cellphone services only) and 41.58% of market share.2 Its principal competitor in Latin America is América Móvil. It offers GSM 900/1800 MHz (Spain) 850/1900 MHz (America) (2G), UMTS 900/2100 MHz (Spain) 850/900/1900/2100 MHz (America) (3G) HSDPA (3.5G) and LTE 2600 MHz (Spain) 1700/2600 MHz (America) (4G) services.The Movistar name has been in use in Spain since the launch of GSM services in 1995. The name became effective worldwide on April 5, 2005 after Telefónica Móviles purchased the BellSouth mobile operations branch in South America. CdmaOne,GSM-1900 (GPRS, EDGE),850/1900 MHz UMTS, HSPA+,1900 MHz LTE.
AT&T Inc: AT&T Inc. is an American multinational telecommunications corporation, headquartered at Whitacre Tower in downtown Dallas, Texas. AT&T is the second largest provider of mobile telephone and the largest provider of fixed telephone in the United States, and also provides broadband subscription television services. AT&T is the third-largest company in Texas (the largest non-oil company, behind only Exxon Mobiland Conoco Phillips, and also the largest Dallas company). As of May 2014, AT&T is the 23rd-largest company in the world as measured by a composite of revenues, profits, assets and market value, and the 16th-largest non-oil company. As of 2016, it is also the 18th-largest mobile telecom operator in the world, with over 128.6 million mobile customers. CdmaOne
CDMA2000 1x, CDMA2000 EV-DO,GSM-850/1900 MHz (GPRS,EDGE)
UMTS, HSDPA, HSPA+,iDEN,1700 MHz UMTS, HSPA+,1700 MHz LTE.
Virgin Mobile: Virgin Mobile is a wireless communications brand used by eight independent brand-licensees worldwide. Virgin Mobile branded wireless communications services are currently available in Australia, Colombia, the United Kingdom, Canada, Chile, France, Saudi Arabia, Poland, South Africa, México, and the United States.Virgin Mobile branded services were formerly offered in Singapore, India and Qatar.Each Virgin Mobile branded entity acts independently from the others, thus the handsets, service plans and network radio interfaces vary from country to country. In a given country, the Virgin Mobile wireless entity is typically a partnership between Richard Branson’s Virgin Group and an existing mobile network operator or mobile virtual network operator. GSM-1900 (GPRS, EDGE),850/1900 MHz UMTS, HSPA+.