Upload: 1710–1785, Download: 1805–1880. GSM-1800 is used in most parts of the world: Europe, Middle East, Africa, Australia, Oceania (and most ofAsia). GSM-1800 uses 1710–1785 MHz to send information from the mobile station to the base transceiver station (uplink) and 1805–1880 MHz for the other direction (downlink), providing 374 channels (channel numbers 512 to 885). Duplex spacing is 95 MHz. GSM-1800 is also called DCS (Digital Cellular Service) in the United Kingdom, while being called PCS in Hong Kong (not to mix up with GSM-1900 which is commonly called PCS in the rest of the world.) Mobile Communication Services on Aircraft (MCA) uses GSM1800.