 Depending on time of day, season of year, solar weather and Earth's geomagnetic field, a signal might reach around the world.In previous decades shortwave (and sometimes high-powered mediumwave) transmission was regarded as the main (and often the "only") way in which broadcasters could reach an international audience.In recent years the proliferation of technologies such as satellite broadcasting, the Internet, and rebroadcasts of programming on AM and FM within target nations has meant that this is no longer necessarily the case.