Low-Earth orbit (LEO) satellite constellations emerge as a cost-effective technology to provide ubiquitous and seamless broadband access. The integration of satellite and terrestrial systems for mobile communications is taking-off with the development of 3GPP non-terrestrial networks (NTN) and the ongoing deployment of private constellations.

Despite the advantages of LEO satellites, satellite-specific aspects - such as the high-speed movement, long communication distances and challenging propagation conditions - compromise the 5G radio mobility management algorithms, which are fundamental to ensure seamless service.

This thesis investigates enhancements for the connected-mode mobility procedure known as handover (HO) in 5G LEO satellite networks with Earth-moving cells. Based on exploiting the deterministic movement of LEO satellites, novel HO solutions are proposed to improve the UE mobility performance as compared with measurement-based 5G NR HO procedures.

The provided system-level simulation results indicate that the use of the satellite trajectories eliminates radio link failures, undesired HO events while maximizes the radio link quality and the cell time-of-stay.