what is VSAT

What is a VSAT?   A very small aperture terminal (VSAT) is a device - known as an earth station - that is used to receive satellite transmissions. The "very small" component of the VSAT acronym refers to the size of the VSAT dish antenna -typically about 2 to 4 feet (0.55-1.2 m) in diameter- that is mounted on a roof on a wall, or placed on the ground. This antenna, along with the attached low-noise blocker or LNB (which receives satellite signals) and the transmitter (which sends signals) make up the VSAT outdoor unit (ODU), one of the two components of a VSAT earth station. The second component of VSAT earth station is the indoor unit (IDU). The indoor unit is a small desktop box or PC that contains receiver and transmitter boards and an interface to communicate with the user's existing in-house equipment - LANs, servers, PCs, TVs, kiosks, etc. The indoor unit is connected to the outdoor unit with a pair of cables. The key advantage of a VSAT earth station, versus a typical terrestrial network connection, is that VSATs are not limited by the reach of buried cable. A VSAT earth station can be placed anywhere - as long as it has an unobstructed view of the satellite. VSATs are capable of sending and receiving all sorts of video, data and audio content at the same high speed regardless of their distance from terrestrial switching offices and infrastructure.

How does a VSAT network work?  A VSAT network has three components: A central hub (also called a master earth station) The satellite A virtually unlimited number of VSAT earth stations in various locations - across a country or continent Content originates at the hub, which features a very large -15 to 36-foot (4,5 -11m)- antenna. The hub controls the network through a network management system (NMS) server, which allows a network operator to monitor and control all components of the network. The NMS operator can view, modify and download individual configuration information to the individual VSATs. Outbound information (from the hub to the VSATs) is sent up to the communications satellite's transponder, which receives it, amplifies it and beams it back to earth for reception by the remote VSATs. The VSATs at the remote locations send information inbound (from the VSATs to the hub) via the same satellite transponder to the hub station. This arrangement, where all network communication passes through the network's hub processor, is called a "star" configuration, with the hub station at the center of the star. One major advantage of this configuration is that there is virtually no limit on the number of remote VSATs that can be connected the hub. "Mesh" configurations also allow for direct communication between VSATs.

 

Advantages of VSAT technology As companies compete for an increasingly savvy customer looking for value (quality and service), information technology and communications networks are becoming tools to achieve business goals. Today's networks must support the need to improve customer service, increase per site revenues and reduce costs (all driving net income growth) - in the most cost-effective manner possible. Further, network managers want virtual 100% availability. They need to easily expand the network when they acquire, move or add new sites to the operations. In addition, they require network flexibility - ease of migration from existing legacy systems as well as addition of new network applications as their companies offer additional services to its customers Businesses and organizations give many reasons for using VSAT networks over terrestrial alternatives. Among them are: Cost-effective Flexibility Accessibility Availability Reliability Versatility Transmission quality High network performance Fast transmissions Control Ability to handle large amounts of data Single vendor solution for both equipment and bandwidth Broadcast capability Ability to handle Voice, Video and Data