MTN :MTN Group, formerly M-Cell, is a South Africa-based multinational mobile telecommunications company, operating in many African, European and Asian countries. Its head office is in Johannesburg.As of 30 September 2015, MTN recorded over 300 million subscribers across its operations.The company sponsored the CAF Champions League football competition as well as APOEL FC, winners of the Cypriot First Division in 2009, 2011, 2013,2014 and participants in the 2009–10 and 2011–12 UEFA Champions League.GSM-900 MHz.
Orange: Orange S.A., formerly France Télécom S.A., is a French multinational telecommunications corporation. It currently employs about 170,000 people, 105,000 of them in France, and has 263 million customers worldwide. In 2012, the group had revenue of €43.5 billion. Its head office is in the 15th arrondissement of Paris, and the current CEO is Stéphane Richard. The company is a component of the Euro Stoxx 50 stock market index.GSM-900 MHz.
Viettel:Viettel Group (full name in Vietnamese largest mobile network operator. It is a state-owned enterprise wholly owned and operated by the Ministry of Defence.GSM-900/1800 MHz,UMTS.
Camtel: Camtel is a national telecommunications and Internet service provider in Cameroon. The company is busy building its network, including: Access to aCDMA (Code Division Multiple Access) network; digitization of the country’s telephone exchanges; and optical fiber along the highway between Douala and Yaoundé, and between Kribi and Lolodorf.GSM.