A global area network (GAN) is a communication system that is subject to virtually no spatial limitation due to the use of satellites. In satellite transmission, the communication satellites are the switching nodes and the uplink and downlinkradio links
from and to the satellites are the transmission links. These high performance uplink and downlink radio links operate with error detection and error correction
. Theend-to-end message delay is relatively high due to the long distance between the ground station
and the satellite. To the user, the global network appears, if at all, as a space or time channel available to him. The transmission speed on such a channel is usually 2 Mbps. Global networks are usually connected to regional wide area networks, but they can also interconnect LAN segments due to their performance. Examples: Telcom, Satellite Business Systems (SBS).