Multibeam satellite communication system and method, and satellite payload for carrying out such a method
| 590 - Abstract: |
| The European Space Agency (ESA) is offering an innovative multibeam satellite system for data communications. The novel technology provides a very high link availability, improved performance when fading effects occur, optimized payload architecture in terms of hardware required. Licence agreement collaboration is sought. |
Description
The invention describes a satellite communication system comprising:
- A multibeam satellite (SAR) for generating a plurality of feeder beams and a plurality of user beams over a region of interest (ROI).
- A plurality of spatially-separated gateway station for providing feeder links to said multibeam satellite via respective feeder beams.
Unlike in conventional multibeam satellite networks, each user beam is associated to several gateway stations. This enables the switching of data from a gateway station to another in case of outage.
In this way the network doesn’t need anymore of backup gateway stations, reducing the number of equipment required.
Moreover, each gateway station may be configured to react to a degradation of the corresponding feeder link by activating Adaptive Coding and Modulation to counteract fading impairments by reducing its throughput. The system supports two different embodiments for implementing such adaptive technique:
- in a first embodiment, the whole operational bandwidth is associated to each gateway station, leaving no gateway redundancy. Accordingly, degradation of one or more feeder links causes a throughput reduction for all the user beams but no complete interruption of the service.
- in a second embodiment, the operational bandwidth is associated to each gateway station with a margin of redundancy. In the event of degradation of a feeder link, other gateway stations can exploit all or a fraction of their unused bandwidth for exchanging data with user terminals which, in normal conditions, exchange data through the degraded feeder link. This ensures that outage of one or more feeder links has no effect on the data throughput.
Innovations and advantages
Most communication systems of the kind operate in the Ka-band. To further increase the capacity, this network allocates the whole Ka-band to the user links, moving the feeder links to higher frequencies, e.g. the Q/V band.
The invention aims at improving the achievable performance in terms of capacity when fading events affect some of the feeder links, and the end to end link availability. The present invention also optimizes the payload architecture in terms of hardware required (in terms of number of equipment and associated power consumption, power dissipation and mass).
Lastly, the system supports two different “adaptive coding and modulation” methods to counteract fading impairments.
Domains of application
This innovation may be applied to more general telecom systems.
