Performance Evaluation of Multipath TCP with Multiple Cellular Networks on High-Speed Trains

In environments with high mobility, such as high-speed trains, the status of wireless signals changes rapidly, leading to network instability and decreased throughput due to frequent handoffs between base stations. Even when applying high-capacity wireless technologies like 5G and 6G to high-speed trains, the existing TCP, which uses a single path, cannot resolve handoff issues occurring in high-speed train environments. To provide faster internet services on KTX trains, KORAIL has introduced a load balancing system with multiple cellular networks. However, since it's not possible to simultaneously utilize the bandwidth of multiple cellular networks, research on applying MPTCP is necessary to address these issues. This paper investigates the characteristics of both the load balancing system with multiple cellular networks and MPTCP to compare their performance in the high-speed train environment. Additionally, a test bed was constructed based on data measured in an actual high-speed train environment to analyze and compare the performance of the load balancing system and MPTCP. In comparison to the existing load balancing system, it has been confirmed that the throughput increases in the MPTCP, and stable data transmission occurs even during handoff events.