A Link Selection Algorithm for Improving TCP Throughput in 5G NTN Systems

5G Non-Terrestrial Networks (NTN) can extend cellular coverage and provide additional satellite radio resources, but the high delay of satellite links may degrade Transmission Control Protocol (TCP) performance in the early phase of a connection. In this paper, we propose a link selection algorithm that initially sends TCP traffic over the terrestrial link and activates the NTN link to ensure efficient utilization of channel resources. Using the ns-3 simulator, we demonstrate that the proposed algorithm increases the TCP download rate by up to 50% compared with baseline solutions.