Development of a prototype of a terrestrial mobile station for voice and data transmission using INMARSAT's network of satellites, with special emphasis in the usage of microwave technology. The Inmarsat-M project was financed by the national programme STRIDE. INESC/INOV was part of a consortium that included CPRM-Marconi (Portugal Telecom international operator), IST (Technical University in Lisbon) and EID (R&D company).