About VSAT - Satellite Technology

VSAT technology is a telecommunication system based on wireless satellite technology. The term VSAT, which stands for very small aperture terminal, refers to a small fixed antenna dish 2.4-m or smaller in diameter [19]. The VSAT unit is configured to support a variety of protocols, including the TCP/IP and PPP for Ethernet connection, as well as X.25, SDLC, Telnet, BSC, and dozens of additional legacy protocols. Thus, it can be used in satellite communications of data, voice and video signals, as well as Internet or Intranet connections.

VSAT technology makes use of small dish, high speed satellite communications to send and receive information.

The technology is widely used in the private sector. No terrestrial (land) telephone lines are required for the use of VSAT technology. VSATs can be used to transmit information wherever there is access to the open sky.

VSAT Deployment Scenarios in Remote Areas

In the areas where there is no wireline (optical fiber or POTS) available, or the areas where the population is so dispersed that the construction of many towers and base stations makes WLL solutions expensive, VSAT can be considered as a viable option for telecom and Internet connectivity with the backbone network. The VSAT system in these situations directly connects remote users to the Internet backbone, which is linked to the PSTN, through the satellite in the sky.

There are generally two possible topologies in VSAT system where the signals are either sent via satellite to a central hub (star network) or the signals are sent directly to VSAT with the hub being used for monitoring and control (mesh network).

[1] The deployment scenario with star network.

In a star network, the hub antenna is in the range of 6-11 meters in diameter. This MES controls, monitors and communicates with dispersed VSATs in remote locations. The VSAT always communicates with central office via the hub or MES through the satellite.

[2] The deployment scenario with mesh network.

In a mesh network, the hub acts as a Network Management Center for channel allocation and policing. This allows voice communications to be established between remote VSAT terminals in a single satellite hop. However, the terminal cost in the mesh network is more expensive than in the star network. In addition, it requires the hub for full functionality.

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