Around 40% of the network still uses outdated analogue technology. (Argentina, which privatised its phones in 1991, has an almost fully digital network.) That, plus equally outdated labour practices, has meant that Brazil's telecoms industry has an average of one full-time worker per 108 lines, less than half the productivity achieved in the United States.

ECONOMIST: A clear line from Brazil

If digital communications are disrupted, the site can switch to analogue technology with assistance from the Radio Amateurs' Emergency Network.

BBC: Bunker mentality: The Cold War bunkers still in use