Amazon voters tally up

Ten years ago, Brazil became the first country to hold fully electronic national elections. By October 2008, the South American nation was adding a new chapter to its rich history of electoral innovation by using broadband connections over mobile satellite links to transmit the poll results. Using a spacecraft orbiting at 36,000km above the equator might not seem the most obvious method for relaying an e-vote from A to B. On closer examination, though, it makes sense. Electronic voting systems usually consist of two devices: a machine at the voters' end on which each voter presses a button or touches a screen to have their say; and a server at the other to count the results. From a communications engineering perspective, the path that digital voting data must follow to link these two devices is the opposite of that in a TV or radio broadcast, where data flows from a central point (the transmission antenna) to an array of receivers what's known as a point-to-multipoint configuration. Voter data travels multipoint-to-point, from an array of emitters to a central receiver.