3D-Cell Control Technology for Frequency Sharing between HAPS and Terrestrial Systems

Abstract

The high-altitude platform station (HAPS) is a promising solution for extreme coverage extension in the Fifth Generation (5G) Evolution and Sixth Generation (6G) eras. By providing radio waves from the stratosphere using HAPS, mobile communications can be made available in all locations that are not adequately covered by conventional mobile communications networks. It is desirable that the HAPS and terrestrial system share a frequency to actualize a direct access service in which terminals connected to the terrestrial International Mobile Telecommunications (IMT) network at 2.7 GHz or less can directly connect to the HAPS. In this paper, we propose a 3D-cell control technology as a load balancing and interference avoidance mechanism when HAPS and terrestrial network share a frequency. Evaluation results based on a 6G system-level simulator show that the load balance and interference-to-noise ratio characteristics are improved in the 2 GHz band.