A Reliable Handover Strategy with Second Satellite Selection in LEO Satellite Networks.

Low Earth orbit (LEO) satellites, which are gaining prominence in the global communications infrastructure, cause frequent handovers due to their high speed. Without a proper handover strategy, the quality of service (QoS) and reliability of users will be reduced. In this paper, we propose the second satellite selection (SSS) algorithm that defines the bit potential to reflect the overall link quality during the service time and considers the temporal dimension that satellite selection depends on. The algorithm predicts the service time, link quality, and expected handover time based on the visible satellite information and selects the optimal selection combination considering the second satellite. We also adjust the predicted time for handover in order to maintain a high average link quality and apply weights to reduce the number of handovers and failures. Simulations conducted in MATLAB, based on Globalstar's two-line element set (TLE), demonstrate a significant reduction in the handover failure rate of up to 95 % and an enhancement in the average bit potential for each selection of up to 22 %, improving user's QoS and reliability when compared to other benchmark schemes.