VSAT, an acronym for Very Small Aperture Terminal, is the term used for a one-way or two-way satellite ground station consisting of a dish antenna smaller than three meters across. The VSAT’s function is to access the signal from a specific orbiting satellite, at which the antenna is pointed, and relay data back and forth from other terminals and hubs.

North American and European units usually operate in the Ku-Band frequencies and use smaller antennas. C-Band VSAT units are in use throughout the rest of the world. They tend to be slightly larger but are better adapted for use in extreme rain conditions.

VSAT systems are attractive where the coverage area is large, where quick installation is required and where terrestrial alternatives are difficult to organize. Because of the convenient size, VSAT technology has made satellite communication an attractive and viable option for a wide range of industrial applications, including mobile communications and broadband VSAT. Some of the most common uses include:

• Point of sale systems (e.g. at stores and gas stations)
• Internet access (e.g. WiFi at a local coffee shop)
• Teleconferencing
• Broadcasting (many TV stations have VSAT-equipped vans)
• Financial feeds from stock markets
• Paging messages

VSAT's Benefits

• availability- easily deployed anywhere in the world
• independence - wireless link completely independent from local infrastructure
• backup for potential disasters
• easy setup - can be set up in a matter of minutes
• strength and speed of the VSAT connection
• security - private layer-2 networks over the air
• pricing - very affordable,
• cost-effectiveness - serves the same content to thousands of locations at once for no additional cost
• onboard acceleration of protocols (eg. TCP, HTTP), allowing the delivery of high quality connections regardless of latency

VSAT Configurations for Interactive (2-way) Communication

When an organization requires a number of remote users to have data access to a central hub, a VSAT satellite communications network is worth considering. Capacity is not a problem with both very small to very large networks all viable. Growth is possible in small steps thus keeping costs related to actual use.  VSAT systems provide both data and voice services, enabling communication between all sites.

Topologies for VSAT networks:

• Star topology: This topology uses a central uplink site (eg. Network operations center (NOC), which transports the data to and from each of the VSAT terminals using satellites Point to point networks may be used to link small ISPs to the internet backbone.
• Mesh topology: In this configuration, each VSAT terminal will relay data over to another terminal through the satellite, acting as a hub, which also minimizes the need for an uplink site
• Star + Mesh topology: This combination can be achieved (as some VSAT networks do) by having multiple centralized uplink sites connected together in a multi-star topology which is in a bigger mesh topology. This topology does not cost so much in maintaining the network while also lessening the amount of data that needs to be relayed through one or more central uplink sites in the network.

View SkyVision's VSAT Installation Manual - Featuring the iDirect Modem. Models: 3100, 5100 and Evolution X3

In this interactive presentation, the first VSAT installation manual featuring the iDirect Satellite Router of its kind, learn step-by-step about the technical requirements of setting up an antenna and a VSAT-based satellite router to access satellite broadband services.

More VSAT resources on the web:

Wikipedia - VSAT Technology

SatSig