The Africa Coast to Europe (ACE) submarine cable has launched Phase II —  the Sao Tomé & Principe-to-Cape Town segment — to expand broadband connectivity and digital services such as high speed Internet access in Africa, PCTechMag reports.

The 5,000-kilometer extension (3106.8 miles) will connect the island of Sao Tomé & Principe in the Gulf of Guinea to South Africa.

When Phase II is completed, ACE will cover a total distance of 17,000 kilometers and bring high speed Internet access to up to 25 countries.

So far, almost 12,000 kilometers of fiber optic cable are already used to connect 18 countries between Europe and Africa including France, Portugal, the Canary Islands (Spain), Mauritania, Senegal, Gambia, Guinea, Sierra Leone, Liberia, Côte d’Ivoire, Benin, Ghana, Nigeria, Equatorial Guinea, Gabon, and São Tomé & Príncipe. Landlocked Mali and Niger are connected by a terrestrial extension.

The submarine cable is owned by France-based telecommunications corporation Orange, together with 19 members of an ACE consortium of operators and administrations including South African mobile service provider MTN.

ACE is a relative late comer to South Africa.

South Africa is already connected to the rest of the world through five submarine cables offering multiple terabits of bandwidth, ITWeb reports.

In just over a decade, South Africa moved from dependency on just one cable — the SAT-2 submarine cable from 1993 to 2002 — to the SAT-3/SAFE (launched in 2002), Seacom (2009), EASSy (2010) and WACS in 2012, said Mark McCallum, director and head of global services Africa at Orange Business Services.

ACE is the first international submarine cable to land in Equatorial Guinea, The Gambia, Guinea, Liberia, Mauritania, Sao Tome and Principe and Sierra Leone.

The ACE consortium invested around US$700 million to build the cable including US$250 million from the Orange Group and its subsidiaries, Orange said in a press release.

Members of the consortium include the following businesses and governments: Benin Telecoms, Cable Consortium of Liberia, Canalink Africa SL, Côte d’Ivoire Telecom, Dolphin Telecom JLT, Gambia Submarine Cable, Guinéenne de Large Bande, International Mauritania Telecom, MEO (Portugal’s telcom), MTN, Orange (France), Orange Cameroun, Orange Mali, Orange Niger, Republic of Equatorial Guinea, Republic of Gabon, République of Cameroun, Sierra Leone Cable Company, Sonatel, and STP Cabo.

Orange says ACE uses the most advanced high-speed broadband fiber optic technology. This includes wavelength division multiplexing that allows the capacity to be increased when needed without additional submarine work being required.

Overall capacity will be boosted to 12.8 terabits per second — (a measurement that prior to the 21st century was unthinkable, according to PCTech) using 100-billion-bits-per-second technology, which supports high-capacity networks, Orange said.

A terabit is 1 trillion binary digit and is used for measuring the amount of data transferred in a second between two telecommunication points or within network devices, according to WhatIs.

Orange says it’s committed to providing widespread Internet access in 20 African countries where it does business and to continue improving the quality of its network service.

Orange claimed to have 263 million customers worldwide as of Sept. 30, 2015, including 200 million mobile and 18 million fixed broadband customers. It had sales of 39 billion euros $49 billion US) in 2014 and 157,000 employees worldwide. Orange also provides IT and telecommunication services under the brand Orange Business Services.

The consortium agreement was signed on June 5, 2010. The cable was manufactured by Alcatel Submarine Networks (ASN) and was laid by ships from ASN and France Telecom Marine. The first phase of the 17,000 kilometer fiber optic cable went into service Dec. 15, 2012.

Orange had 98,000 employees in France and 157,000 worldwide as of Sept. 30, 2015.