  In the present article, a new system architecture for the next generation of
satellite communication (SatComs) is presented. The key concept lies in the
collaboration between multibeam satellites that share one orbital position.
Multi-satellite constellations in unique orbital slots offer gradual deployment
to cover unpredictable traffic patterns and redundancy to hardware failure
advantages. They are also of high relevance during the satellite replacement
phases or necessitated by constraints in the maximum communications payload
that a single satellite can bear. In this context, the potential gains of
advanced architectures, that is architectures enabled by the general class of
cooperative and cognitive techniques, are exhibited via a simple paradigm. More
specifically, the scenario presented herein, involves two co-existing multibeam
satellites which illuminate overlapping coverage areas. Based on this scenario,
specific types of cooperative and cognitive techniques are herein considered as
candidate technologies that can boost the performance of multibeam satellite
constellations. These techniques are compared to conventional frequency
splitting configurations in terms of three different criteria, namely the
spectral efficiency, the power efficiency and the fairness. Consequently,
insightful guidelines for the design of future high throughput constellations
of multibeam satellites are given.
