GT to GT data transmission in case of classical bent pipe satellite. On-board switching and multi-beam satellite systems
Multi-beam satellite systems with bent-pipe satellites are gaining tremendous attention from the industry and the research organisations since they enable to cover a wide area with a multitude of narrow, high gain beams, and to highly increase the total system capacity by reusing the same frequency slots in different non adjacent beams. Nevertheless, in such systems, ground terminal to ground terminal(s) communication is only performed via two consecutive satellite hops, all data being first transmitted from the transmission ground terminal to an intermediate gateway and then forwarded to the reception ground terminal(s).
Advantages and draw-backs of on-board switching
On-board switching therefore considerably enhances the resource utilization and performance of the multi-beam satellite systems and displays the following advantages:
Nevertheless, several critical issues should unfortunately be tackled when satellite systems with on-board switching are designed:
In addition, multi-beam satellite systems suffer also from Co-Channel Interference due to the reuse of the same frequency in different up-link and down-link beams and the imperfect transmission and reception properties of the satellite antennas.
On-board switching DLR related work
The work carried out at DLR in the field of on-board switching consists in:
On-board switching related researches have been carried out in the framework of two ESA projects: