Li-Sheng Chen¹ and Shu-Han Liao², ¹National Ilan University, Taiwan, ²Tamkang University, Taiwan

Low Earth Orbit (LEO) satellites exhibit high mobility, leading to frequent handover challenges. Addressing these handover issues is crucial for maintaining seamless and stable service connections. In this paper, we tackle the handover problems in LEO by utilizing the D1 events, as discussed in the 3rd Generation Partnership Project (3GPP). Unlike terrestrial networks, the difference between the reference signal received power (RSRP) at the cell edge and the cell center is minimal in non-terrestrial networks (NTN). Therefore, 3GPP has been exploring location-based handover methods using absolute thresholds instead of comparing the RSRP of serving and neighboring cells in handover events. We introduce the D1 event as a handover trigger and explore handover parameters in conjunction with the UE’s position (referred to as enhanced D1) to ensure reliable handover for NTN. Simulation results show that enhanced D1 handover outperforms traditional D1 handover, particularly in reducing ping-pong effects and handover failures (HOF).

Low earth orbit (LEO), Non-terrestrial networks (NTN), Mobility, Satellite communication, Handover