PAGE CONTENTS
Objectives
The project was based on four major pillars that support the complete structure:
- Hybrid networks as a result of the merge of transparent and regenerative transponders into the same service,
- On board processing techniques,
- Adaptive modulation and coding, making use of the available bandwidth with the most optimised efficiency,
- Adaptive switching applied to the OBP, making a design able to cope with different quality of services and to support labelling switch, which provides huge possibilities to the network in multi-beam scenarios.
With these concepts in mind, the main objective of the project has been to develop a laboratory model of an on board processor chain that could be used to validate the new algorithms. This laboratory model will be the baseline for new OBP generations, and will allow the procurement of qualified and flight models to potential satellite operators.
Challenges
The first main objective of the project was to design an end-to-end satellite system that would take into account not only the specificities of the different actors involved but also the operator’s point of view. Afterwards, the impact on the on board processor and on the different sections was analysed and every section of the OBP was detailed.
The final objective was to implement and test in a laboratory model, the newly designed algorithms and to check their performances in a simulated environment.
Plan
The project was structured into two phases to be developed over 30 months:
- Architecture and requirements definition
During this phase, system specifications were established based on different services and network architectures. These specifications were translated into requirements for the different units and specially for the OBP and the channel simulator. The application of the requirements derived into the selection of the most suitable architecture for the processor.
- Implementation and Validation
The second phase was longer and took as inputs the outcomes of the former activities. Most of the resources were centred in the activities related to the on board processor new algorithms. They had to be refined, implemented and validated in simulation and in the laboratory hardware. Finally, all the units had to work in a coordinated way so that the information integrity was maintained from one end of the demonstrator to the other. The software units were completely specified and implemented during this second phase as they are adapted to the laboratory environment, that is to say, they are not part of the communications system defined in the first phase.
Current Status
The final review of the project has been successfully held. During the meeting, the different units were reviewed providing a brief description of the new algorithms implemented and a detailed overview of the tests that have been performed on them. The final integration in the laboratory and the adaptability of the forward channel to the link conditions has also been demonstrated.
