EU's R&D activities on third generation mobile satellite systems (S-UMTS)

This article summarizes the European Union (EU) activities in the ACTS program satellite component of the UMTS. The projects INSURED, NEWTEST, SECOMS, SINUS, and TOMAS are introduced, and their R&D work on the services implemented in the different test platforms, the network integration scenario into the UMTS network, the studies performed for the air interface, the mobile terminals implemented, and the demonstrated applications are summarized. Furthermore, a new approach using neural networks for adaptive channel equalization and the concept for an EHF/Ka-band system are introduced.