Passengers stand in front of an outlet of South African mobile phone operator MTN at Johannesburg's OR Tambo international airport, November 27, 2015. Nigeria will start new talks with South African mobile phone operator MTN "very soon" to settle a dispute over a $3.9 billion fine but the final decision rests with President Muhammadu Buhari, the communications minister said. Picture taken November 27, 2015. REUTERS/Mike Hutchings 

A woman walks past a bus shelter advertising South Africa's MTN Group in Johannesburg in this May 27, 2008 file photo. Launched in 1994, South Africa-based MTN has grown rapidly to become the largest mobile phone company in Africa, with operations in 16 countries on the continent, and a presence in a further five countries in the Middle East. To match Feature FRONTIERS/AFRICA REUTERS/Mike Hutchings/Files (SOUTH AFRICA - Tags: BUSINESS) 

A township resident chats on his mobile phone in Hout Bay near Cape Town in this June 22, 2006 file photo. Mobile operators are scrambling to gain a foothold in Africa, where cell phone penetration hovers at just 15 percent and growth is ripe for those with a stomach for risk. But a decade after mobile technology took off on the continent, most affluent urbanites already have phones, making poor rural areas the new battleground for operators seeking growth. Picture taken June 22, 2006. To match feature TELECOMS AFRICA RURAL REUTERS/Mike Hutchings (SOUTH AFRICA) 

-PHOTO TAKEN 01DEC05- Residents make calls from a phone shop set up inside an old shipping container amongst the shacks of Khayelitsha township near Cape Town, South Africa December 1, 2005. [African cell phone operators are at the vanguard of an industry drive to connect billions of poor people in emerging markets, but they must cut tariffs, tailor services and push governments to slash tax to succeed. Industry executives and commentators told a mobile telephony conference this week African operators stood to double their collective customer base to some 250 million by the end of 2010 -- a quarter of Africa's population -- if they played smart.] Picture taken December 1, 2005. 

Residents make calls from a phone shop set up inside an old shipping container amongst the shacks of Khayelitsha township near Cape Town, South Africa December 1, 2005. African cell phone operators are at the vanguard of an industry drive to connect billions of poor people in emerging markets, but they must cut tariffs, tailor services and push governments to slash tax to succeed. Industry executives and commentators told a mobile telephony conference this week African operators stood to double their collective customer base to some 250 million by the end of 2010 -- a quarter of Africa's population -- if they played smart. Picture taken December 1, 2005. To go with story Africa-Telecoms. REUTERS/Mike Hutchings 

A woman washes clothing beside an old shipping container that serves as a phone shop amongst the shacks of Khayelitsha township near Cape Town, South Africa December 1, 2005. African cell phone operators are at the vanguard of an industry drive to connect billions of poor people in emerging markets, but they must cut tariffs, tailor services and push governments to slash tax to succeed. Industry executives and commentators told a mobile telephony conference this week African operators stood to double their collective customer base to some 250 million by the end of 2010 -- a quarter of Africa's population -- if they played smart. Picture taken December 1, 2005. To go with story Africa-Telecoms. REUTERS/Mike Hutchings 

A woman stands beside an old shipping container that serves as a phone shop amongst the shacks of Khayelitsha township near Cape Town, South Africa December 1, 2005. African cell phone operators are at the vanguard of an industry drive to connect billions of poor people in emerging markets, but they must cut tariffs, tailor services and push governments to slash tax to succeed. Industry executives and commentators told a mobile telephony conference this week African operators stood to double their collective customer base to some 250 million by the end of 2010 -- a quarter of Africa's population -- if they played smart. Picture taken December 1, 2005. To go with story Africa-Telecoms. REUTERS/Mike Hutchings 

Residents make calls from a phone shop set up inside an old shipping container amongst the shacks of Khayelitsha township near Cape Town, South Africa December 1, 2005. African cell phone operators are at the vanguard of an industry drive to connect billions of poor people in emerging markets, but they must cut tariffs, tailor services and push governments to slash tax to succeed. Industry executives and commentators told a mobile telephony conference this week African operators stood to double their collective customer base to some 250 million by the end of 2010 -- a quarter of Africa's population -- if they played smart. Picture taken December 1, 2005. To go with story Africa-Telecoms. REUTERS/Mike Hutchings 

Residents make calls from a phone shop set up inside an old shipping container amongst the shacks of Khayelitsha township near Cape Town, South Africa December 1, 2005. African cell phone operators are at the vanguard of an industry drive to connect billions of poor people in emerging markets, but they must cut tariffs, tailor services and push governments to slash tax to succeed. Industry executives and commentators told a mobile telephony conference this week African operators stood to double their collective customer base to some 250 million by the end of 2010 -- a quarter of Africa's population -- if they played smart. Picture taken December 1, 2005. To go with story Africa-Telecoms. REUTERS/Mike Hutchings