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What is a VSAT? |
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VSAT or Very Small Aperture Terminals are small, software-driven earth stations (typically 0.9-1.8 meters, which equates to 3-6 feet) used for the reliable transmission of data, video, or voice via satellite. It requires no staff or additional technology to operate it. It simply plugs into existing terminal equipment.
A VSAT network consists of a central hub (master earth station), many remote VSATs, and the satellite transponder space segment. The hub station is always larger than the remote VSATs and is frequently located near the user's main data processing center. A VSAT is located at each end-user location, which can consist of several dozen to several thousand sites. From a communications perspective, there are two segments within the network transmission process. They include the earth segment, which consists of the equipment at the hub and VSAT locations; and the space segment, which is the link to and from the satellite.
The VSAT equipment consists of two units: one placed outdoors for a line-of-sight to the satellite, and one placed indoors to interface with the user's communications device (e.g. data terminal equipment). Typical mounts include ground, roof, or wall mounted arrangements. The outdoor unit consists of a small antenna, mount, and electronics for signal reception and transmission. The indoor unit is a small desktop box that contains receiver and transmitter boards and an interface to the user's equipment. Both units are connected via cabling. The Advantages of a VSAT Network The advantages of a VSAT network are numerous and the demand has increased rapidly over the past 10 years in many industries including financial, banking, brokerage, retail, gas station/convenience store, restaurant, pharmacy, and hospitality. A VSAT network can be provided through a purchase or lease arrangement with fixed transmission costs regardless of distance or number of receiving sites. Depending on the capital investment outlay, shared or private hub options are available. Another advantage is control. The user retains complete control of the way information is communicated within the network. Network control also generates flexibility, especially where new VSAT sites need to be added, or existing sites need to be moved or removed from the network. The inherent broadcast capabilities of a satellite-based network make VSATs an ideal training vehicle. Broadcast video is an easy overlay to a VSAT network; the same antenna is used for both the data and the video. Broadcast audio can also be received using the same antenna. This minimizes the space and cost of providing the service. And a final key advantage is the high availability and excellent transmission quality a VSAT network provides for its users. Notably, VSAT networks also guarantee the highest performance levels among all communications alternatives. And, all of this can be accomplished with a call to a single communications provider. |
Many
remote locations with end-user terminals can be connected through VSATs to a centralized processing center, or
the hub. Outbound information (from the hub to the VSATs) is sent up to the communications satellite's transponder,
which beams the information down for reception to 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.
The hub station serves as the center of the star-configured network. Another common VSAT network configuration
is point-to-multipoint (broadcast networks).
The
pivotal operations in the transmission occur on the ground. The hub controls the entire operation of the communications
network. At the hub is a network management system server, which allows a network operator to monitor and control
the communications network through the integration of sophisticated hardware and software components. The operator
has the ability to view, modify, and download individual configuration information to the individual VSAT. Network
management system workstations are located at the user data center.
