Mumbai University > Satellite Communication and Networks

Topic : Satellite Links

Marks: 10M

There are three different methods to establish or address connectivity issues on the satellite.These methods are common for transparent as well as regenerative types of satellites.These connectivity techniques are:

1. on-board connectivity with transponder hopping
2. On-board connectivity with switching or by using switch matrix
3. On-board connectivity with beam scanning

The second method that is On-board connectivity with switching is known as connectivity with transparent processing

The drawback of requirement of increase in the number of transponders as square of number of beams in use in the method of transponder hopping is eliminated with transparent processing switching technique.

In this switching or transparent processing channel switching is implemented instead of beam switching in transponder hopping method.

This transparent switching method is also sometimes called as satellite switched TDMA operation.

In this method the payload (satellite transparent type ) here has programmable switch matrix which has its input and output equal to number of beams in operation.

This matrix connects each uplink beam to each downlink beam by way of receiver and transmitter.Therefore number of beams are equal to number of transponders.

The distribution control unit establishes sequence of connections states between each input and output during specific period of time in such a way that carriers arriving at satellite in each beam are routed to their destination beams.

Stations store traffic from users and transmits it in the form of bursts when required interconnection between beams is released.This technique is used with digital transmissions.