VSAT

VSATs (Very Small Aperture Terminals) is a two way, lost cost, ground micro station for transmitting data to and from communication satellites. A VSAT has a dish antenna with diameters between 75 cm to 1 m, which is very small in comparison with 10 m diameter of a standard GEO antenna. It accesses satellites in geosynchronous orbits or geostationary orbits. Data rates in VSATs ranges from 4 Kbps to 16 Mbps.

Configurations of VSATs

• Star Topology − This has a central uplink site which transmits data from and to each VSAT through the satellite.

• Mesh Topology − Each VSAT transmits data via the satellite to the other stations. The above diagram shows mesh topology of VSATs.

• Combination of the above

Uses of VSATs

• In narrowband data − e.g. point – of – sale transactions using debit cards or credit cards, RFID data

• In broadband data − e.g. Internet access to remote locations, VoIP

• Mobile communications

• Maritime communications