This paper outlines the N-STAR satellite mobile packet communication system and its key features and presents the throughput performance. n e system was developed to have the compatibility with the terrestrial mobile packet communication system called PDC-l? The system has been providing Internet and Intranet access service for those customer where the terrestrial system does not cover, mainly maritime users, since March 2000. To realize the high throughput communication system economically, an asymmetrical channel arrangement and an efficient return link channel assignment scheme were developed. High efficiency FEC and ARQ were also adopted at radio link to cope with GEO satellite propagation delay. The field test reveals this system has achieved a good throughput performance.