Joint User Association and Handover Strategy for Large Scale LEO Satellite Constellation Networks.

With the rapid development of large scale low earth orbit satellite constellation networks (LS-LEOSCN), user association and handover techniques become more important in improving the service performance and reducing the handover times. This paper analyzed the relationship between user association and handover in LS-LEOSCN, to decrease the propagation delay jitter (PDJ) and handover times (HOT). Specifically, the following two questions are focused: 1) How should the user terminals (UTs) choose a proper satellite? 2) When the UTs should handover to another satellite? Grouping-based user association strategy is proposed based on analyzing the cross seam effect. A Grouping-based biased handover strategy is designed hereinafter. Simulation results show that the proposed joint user association and handover (JUAH) strategy works well in both polar and walker LS-LEOSCN. The PDJ and HOT can be significantly decreased by 39.83%, 63.25% compared with traditional max-SINR user association and typical handover strategy, respectively.