Hybrid satellite/terrestrial netw orks: State of the art and future perspectives

In this paper, the main role of satellite systems in hybrid satellite/terrestrial networks will be highlighted, as well as the main functions which should be performed to optimize the performance of these hybrid networks. Then, some typical services believed to occupy a great portion of the future telecommunication service market and benefiting from these hybrid architectures will be presented. Generally speaking, the list of hybrid architectures presented in this paper is not exhaustive but reflects the main work carried out in the institute of communications and navigation of DLR and in the framework of the Satellite Communications Network of Excellence "SatNEx" subsidized by the European Union, more accurately in the focus topic "Hybrid broadband network architectures" of the Joint Activity 2130 "Broadband Access Network". The critical issues related to hybrid satellite/terrestrial architectures will be identified and analyzed all along this paper and illustrated by selected realistic examples.