|
Ground Station: By Ground station we are referring to the VSAT( Very Small Aperture terminal) and its router which receive from and transmit data to satellites. As explained earlier, this could be owned by an ISP from which an internet user or network of users could gain access via phone lines and modems or could be owned by an institution or organization itself. A VSAT consists of two parts, a tranciever (a device that both transmits and receives analog or digital signals) which is placed outdoors in direct line of sight to the satellite and a device that is placed indoors to interface the transceiver with the individual communications device, such as a personal computer. The transceiver receives or sends a signal to a satellite transponder in the sky. The satellite sends and receives signals from a ground station computer that acts as a hub for the system. Each end user is interconnected with the hub station via the satellite, forming a star topology The hub controls the entire operation of the network. For one end user to communicate with another, each transmission has to first go to the hub station that then retransmits it via the satellite to the other end user's VSAT. VSAT can handle up to 56 Kbps. |
