What is VSAT?
VSAT stands for Very Small Aperture Terminal – it’s a catchy acronym and as such it has been adopted by all for every type of satellite product from small components of a system to complete systems. Because the term really hinges around the small size of the antenna it has been used to describe both one-way and interactive systems. Typically, interactive Ku-band antenna sizes range from 75 centimetres to 1.8 metres. One way systems can use antennas as small as 45 centimetres.
Who uses VSAT?
VSAT is used by anyone in rural and remote areas. Car dealerships, gas stations, lottery systems, banks, insurance companies, pharmacies, general stores, supermarkets, healthcare companies, manufacturers, couriers, hotel chains, car rental businesses, food manufacturers, heavy industries, mines, electrical utilities, oil and gas pipelines, energy production and exploration, timber companies, plantations, various government departments and agencies… and any others you can think of. Satellite internet can reach nearly any place on Earth!
What are the site requirements for a VSAT installation?
Depending on site location within the satellite’s footprint, a dish will normally be between 1.2m and 4.5m diameter and mounted on a flat roof or solid base. Suitable space and strength will be required to hold the dish, and line of sight with the satellite is necessary.
An external mains power source is required for the ODU. The Indoor Unit requires a stable mains power supply and suitable dry location. The customer will be fully advised to the exact requirements upon successful survey.
Who can install the VSAT system?
The terminal has to be installed by a certified installer. Indeed special skills for installing and commissioning are needed, which go well beyond the installation of a satellite reception-only system.
What is a star VSAT network?
This form of star network allows any number of VSAT sites to have two-way communication with a central hub. Juch-Tech Inc. operates this type of VSAT network for the satellite internet services it provides.
What is a point to point VSAT network?
A point to point network allows two-way communications between two VSAT sites.
What is one-way satellite?
One way systems rely on a transmitting station which transmits one or more carriers to the satellite which re-broadcasts the signal over its coverage area. All receive-only VSATs under the satellite footprint can then receive the signal or the user/operator is able to define groups of VSATs from one to all on the network. Broadcast systems are used for data and audio. The most popular application for data is the transmission of financial feeds
What are the differences between Ku and C-Band VSAT?
The terms Ku-Band and C-band in VSAT refer to the frequency ranges in Gigahertz (GHz) that signal transmits and receives on. These signals are produced by BUC’s and received by LNB’s
For C-Band this range is 3.7 to 4.2GHZ for downlink, and 5.9GHz to 6.4GHz for uplink. This is also the same frequency ranges that terrestrial microwave networks use and so C-Band VSAT is disrupted by high concentrations of cellular (mobile) networks. On the other hand, Ku-Band frequencies are used only for VSAT and are between 11.7GHz and 12.2GHz for downlink, and 14.0 to 14.5GHz for uplink.
Each frequency range has it’s own pros and cons. An example is that C-Band is less susceptible to rain fade, where the signal is absorbed by water in rain or heavy clouds, and so will usually stay online during normal rainfall. Meanwhile, Ku-Band is less susceptible to sun outage, where solar interference prevents the satellite signal from being received and transmitted. Overall, rain fade will cause a Ku-Band site to lose signal much more often than C-Band will be disrupted by sun outages (as sun outage only occurs during the spring and fall seasons).
