The geostationary satellites are placed at about 36.000 Km from the Earth and they turn around it at the Earth rotation speed. In this manner they result immobile under a prefixed point, in general it is perpendicular to the Equator.
 
 

The radio signal propagation time to cover the distance between the artificial satellite and the Earth's surface is between 239,6 ms and 279,0 ms, while the delay for a message transmission and its reply reception is not more than 558 ms.
This delay is relevant for the communication protocol behaviour, so special tests are required.
The LSU+ allows to simulate the Satellite Delay for a large set of situations.
 
 

The queue length depends on the channel rate and on the required delay: so the Buffer dimension, expressed in bytes, is (Speed/8*1000*Delay), where the Delay is the period of time required (expressed in seconds), the Speed is the rate of bit (Kb/s).
For example, for a Delay of 240 ms and a Speed of 64 Kb/s the Buffer dimension is 1.920 bytes. While for a Speed of 2048 Kb/s, the Buffer dimension is 61.440 bytes.
 
 

For this application the minimum configuration includes:

•  Line Server Unit Plus;
•  Satellite Delay Module.