Non uniformly sampled power control scheme for TCP-based data transfers on a faded satellite link

Rain fading has appalling effects on TCP/IP packet based satellite links, increasing the BER and hence reducing the link throughput. Furthermore, deep rain fades may result in unavailability of the satellite link. To reduce these effects, a power control scheme is implemented and may provide an efficient usage of the satellite power source. Control signals embedded in the asynchronous packet traffic result in non-uniformly sampled signals with highly variable intersample times. Today's control schemes do not deal with such sampling, which leads to poor performances. In order to improve the power regulation, a PID delay controller is proposed based upon non-uniform sampling filtering. A deep channel gain fade scenario has been used to evaluate its performances on LEO, MEO and GEO satellite constellations. The control signal is transmitted within a synthetic FTP source activity trace generated by a self-similar model of the burst transmission of traffic. Simulation results show the improved performances of the proposed power control scheme when compared with a traditional one.