A Dynamic Exclusive-Use Spectrum Access Method for Millimeter-Wave Mobile Systems Toward 6G

In this paper, we propose a dynamic exclusive-use spectrum access (DESA) method to improve the licensed millimeter-wave (mmWave) spectrum utilization of all mobile network operators (MNOs) of a country. The proposed DESA method considers exploiting the secondary spectrum trading such that each MNO can share mutually a part of its licensed mmWave spectrum exclusively with other MNOs in a dynamic and ondemand basis for a certain duration of time. We formulate the problem for the proposed method and present a heuristic iterative algorithm to find the optimal amount of shared spectrum for each MNO at each agreement term. We derive system-level average capacity, spectral efficiency (SE), and cost efficiency (CE) metrics for all MNOs countrywide. With extensive numerical and simulation results, for an example scenario of a country with four MNOs each assigned statically with an equal amount of 28 GHz mmWave spectrum, we show that the proposed method can improve the countrywide SE by 25% and CE by 20%. Moreover, the proposed method can achieve the expected SE requirement for the sixth-generation (6G) mobile network by reusing the same mmWave spectrum to 20% less number of buildings of small cells per MNO.