Inter-satellite links for advanced space networks

Satellite networks will be important elements of the future Global Information Infrastructure (Gn): as a complement to terrestrial networks, satellite communication networks have the significant advantage to provide instantaneous bandwidth-on-demand wherever required, either for short service periods or for long-term services without the need for expensive terrestrial infrastructure upgrade. This flexible bandwidth allocation capability at ubiquitous coverage makes satellite networks and, in particular, their combination with terrestrial networks attractive for a cost efficient development of advanced services interconnecting the world's regions. Inter-satellite links (ISL's) are essential for the design of advanced satellite networks. Rf-based ISL's were already successfully used in various scientific, commercial and military satellite systems. However, the development of broadband satellite networks requiring ESL data rates in the Gbps range has stimulated the development and qualification of new, high-performance ISL terminals operating in the optical frequency domain. The performance of those Optical ISL Terminals offers new perspectives for the development of advanced broadband satellite constellations. This paper will discuss concepts for satellite network architectures for a future GII and will present the technology and performance of today's state-of-the-art Optical ISL Terminals usable for such satellite networks.