This paper proposes a method to overcome the cross-seam in a low Earth orbit (LEO) satellite network. In cross-seam, satellite links cannot be established due to differences in satellite movement directions. The proposed method involves utilizing ground relay to resolve this problem. The Walker-Star constellation has polar regions and cross-seams, where inter-satellite link connection is impossible due to relative velocity. In this paper, we compare the performance results in a satellite network when ground relay is utilized in a cross-seam. We analyze the propagation delay and the number of satellite hops. It analyzes satellite communication performance with and without a ground relay to major cities from Seoul. Also, the maximum performance improvement provided by the ground relay is analyzed. As a result of the analysis, the ground relay reduces propagation delay by up to 76% and reduces satellite hop count by 89%.
This research is supported by the Institute of Information & Commun. Technology Planning & Evaluation (IITP) grant funded by the Korea government (MSIT) (No. 2024-00396992, Development of Cube Satellites based on Core Technologies in Low Earth Orbit Satellite Communications) (No. 2022-0-00704, Development of 3D-NET Core Technology for High-Mobility Vehicular Service).
