This started happening in around 2000 when DTT began being used in many countries. It takes a long time to do, because older television sets could not receive DTT signals, and needed either a new television or a set-top box. During this time, broadcasters keep an analog signal broadcasting until enough people have switched to digital. Berlin was the first city to turn off all analog TV signals on 3 August 2003. Luxembourg was the first country to do this completely in September 2006.