This paper presents an investigation of satellite radio access technology for beyond IMT-2000 systems. Although we could not see any active role of a satellite system in the 3G networks, satellite system will provide strong advantages in future systems for certain applications. Because a satellite link has longer round trip delay than a terrestrial link, we need technologies that would make the satellite component especially efficient. After presenting the satellite radio interface of the 3G system, we suggest several points which need to be considered in the beyond 3G systems. We also suggest a few candidate technologies with various simulation results.