This NY Times article summarizers the current projects to link East African countries to the rest of the world with undersea fiber optic cables. Drivers for the push are also discussed:

At the moment, the Indian Ocean’s eastern African seabed is the only one in the world without a submarine fiber-optic cable, forcing the region to rely heavily on limited and expensive satellite links. As a result, countries along the coast and in its hinterland have some of the highest communications costs in the world.