Investigation of single-hop connections between user terminals in geostationary mobile satellite communication systems

The number of subscribers in geostationary mobile satellite communication systems has been increasing, as a result of the increase voice communication between user terminals. In this situation, there is a strong demand to improve the communication quality of the double-hop connection between two user terminals. As an means of reducing the voice delay, we developed four single-hop connection methods in traffic channel frames are sent through the satellite only once. After comparing these methods with the conventional one, we found that the method using a through repeater satellite and one using a regenerative transponder on board the satellite were promising single-hop connection methods. In particular, we found that using a newly developed common control channel is promising for the former method, and that using frame decomposition and reassembly for communication frames is promising for the latter.