Spectrum allocation for current wireless communication systems is performed by the regulatory and licensing bodies, who allocate spectrum bands for given applications. This strict allocation severely limits the effectiveness and flexibility of the spectrum use. Cognitive Radio (CR) has been demonstrated as a key emerging technology to provide flexible and efficient use of the available spectrum by allocating frequency bands dynamically, and to improve the performance of radio systems in congested or jammed environments. CR systems are also able to monitor and deal with degrading communication performance or regulatory constraints.
The SCREEN project proposes to extend the concept of cognitive radio to space and particularly to Satcom applications. CR has never been used or tested in space, since previous research has been focused in terrestrial technologies. While it has already been demonstrated that CR technology radically improves the performance for terrestrial applications at many different levels, the same benefits also apply in Space and especially in the Satcom segment, where the services provided need to ensure quality to the clients, for market competitiveness. SCREEN has been initiated for two relevant reasons: The first is the need to innovate that emanates from the urge to stay competitive in future space communication systems. The second is the public need for massive network capacity, which originates from the rapid growth of bandwidth usage and frequency occupation. The electromagnetic spectrum is a scarce resource and, in addition, legally constrained. As a result, growing traffic establishes demands for faster and more flexible networks as well as more autonomous and capacity-supplying configuration options.
By addressing this topic and demonstrating its capabilities and benefits for space applications, SCREEN will contribute to a better management of this scarce resource that is bandwidth. CR has the potential to enable different approaches for managing the growing satellite communication demands and provides flexibility to explore new types of hybrid networks. Satcom operators will benefit from having the flexibility to allocate frequency slots dynamically, according to the instantaneous traffic patterns, instead of reserving fixed bands within regulatory constraints. Additionally, by optimising the spectrum management, Satcom operators can accommodate more users at the same time, without sacrificing the network performance.