Electronic Communication: V-SATs

V-SATs are used to access those satellites which revolve in the geosynchronous orbit to move the data from one terminal to other terminals. These terminals are the earths stations which are interconnected in mesh configuration but the master earth stations called as Hub are connected in star topology. V-SAT is a very small aperture terminal, a two-way satellite ground station having a size of less than 3 meters with a dish antenna. The size of V-SAT antenna varies from 75cm to 1.2m.

High powered components and antennas are used in the V-SAT technology. In addition to a receiver, V-SAT also has a transmitter that sent the signal back to the originating satellite for which each transponder provides a return path with a separate frequency shared by other terminals using a TDMA technology.

V-SATs operating in star topology transport data via satellite to each V-SAT terminal through Network Operating Centers where as those working in mesh topology, transfers data to each terminal by acting as a hub rather using any such centers.

V-SATs operate in three frequency band which are Band – C, Band – Ku & Band – Ka. Lets consider each one by one.

Band C: It has a frequency of 3 to 7 GHz having large footprint area, deliver low power with minimum rainfall effect.
Band Ku: This band has medium foot-print area and power with moderate rainfall effect operating in the range of 10 to 18 GHz.
Band Ka: It has the highest range of frequency i.e. 18 to 31 GHz and power delivery but the footprint is small and the rainfall effect is also severe.

As we said earlier that V-SAT at each customer location has a transmitter which sends the signal back to its originating satellite. This returned path is transmitted in the L-Band to a low noise block converter device. Hence signal is converted into higher satellite transmission frequency, amplified and finally emitted to the dish antenna that covers the entire satellite with its beam avoiding the uplink frequencies used by its adjacent satellites to prevent the interference.

V-SATs are easily deployed in few minutes. Due to its wireless connectivity to all the stations, it is very helpful in disaster or back up recovery services. With the V-SATs, customer gets a high quality internet performance with the same speed at every location. V-SATs using broadband technology enable to deliver the same data to thousand of location simultaneously without any additional cost.

Nowadays, V-SATs systems are available online in Ka-Band that provides higher bandwidth rates for lower cost. V-SATs are applied for different applications due to the introduction of FSS (Fixed Service Satellite) some of which are listed below: