  This paper explores the evolution of Radio Access Network (RAN) architectures
and their integration into Non-Terrestrial Networks (NTN) to address escalating
mobile traffic demands. Focusing on Low Earth Orbit (LEO) satellites as key
components of NTN, we examine the feasibility of RAN function splits (FSs) in
terms of fronthaul (FH) latency, elevation angle, and bandwidth (BW) across LEO
satellites and ground stations (GS), alongside evaluating performance of
Conditional Handover (CHO) procedures under diverse scenarios. By assessing
performance metrics such as handover duration, disconnection time, and control
traffic volume, we provide insights on several aspects such as stringent
constraints for Low Layer Splits (LLSs), leading to longer delays during
mobility procedures and increased control traffic across the feeder link in
comparison with the case when gNodeB is onboard satellite. Despite challenges,
LLSs demonstrate minimal onboard satellite computational requirements,
promising reduced power consumption and payload weight. These findings
underscore the architectural possibilities and challenges within the
telecommunications industry, paving the way for future advancements in NTN RAN
design and operation.
