Investigations on Free-Space optical links within SatNEx II

The objective of this paper is to describe recent activities and investigations on FSO and the excellent results achieved within international COST actions (like COST 270, COST 291, COST 297 (HAPCOS)) and the 6^th EU-framework programme (like SatNEx and CAPANINA). In a first part, the FSO technology is briefly discussed. Then its behaviour in different networking architectures is explained to elaborate its potential and suitability for the future next generation networks (NGN). In a second part, the recent investigations in airborne and satellite application scenarios are discussed. Then, the short-range FSO systems built for last mile connectivity are explained. Finally, our recent investigation results on modelling the FSO channel under fog conditions and atmospheric turbulence are presented. Additionally, some recent major performance improvement results obtained by employing hybrid systems and using some specific modulation and coding schemes are presented.