Land-based flight radar systems are incapable of covering about 70 percent of the world’s surface, so a United Nations conference has agreed to dedicate a chunk of radio spectrum for a global, space-based flight tracking system.
The Wednesday accord by the World Radiocommunication Conference (WRC) in Geneva was, in part, a reaction to the disappearance of Malaysian Airlines flight 370 last year. Aircraft that can send signals known as Automatic Dependent Surveillance-Broadcast, or ADS-B, to the ground will be able to send those signals to satellites. The global plan is expected to be implemented by 2017.
“The frequency band 1087.7-1092.3 MHz is currently being utilized for the transmission of ADS-B signals from aircraft to terrestrial stations within line-of-sight. The World Radiocommunication Conference (WRC-15) has now allocated this frequency band in the Earth-to-space direction to enable transmissions from aircraft to satellites. This extends ADS-B signals beyond line-of-sight to facilitate reporting the position of aircraft equipped with ADS-B anywhere in the world, including oceanic, polar and other remote areas,” the UN International Telecommunication Union (ITU) said in a statement.
No Androido antigo, os controles de volume eram separados para sons de sistema, notificações e toques de chamada. Agora os tres estão juntos em um controle só que abaixa ou aumenta os tres volumes como sendo um só.