  This article introduces a new approach to address the spectrum scarcity
challenge in 6G networks by implementing the enhanced licensed shared access
(ELSA) framework. Our proposed auction mechanism aims to ensure fairness in
spectrum allocation to mobile network operators (MNOs) through a novel weighted
auction called the fair Vickery-Clarke-Groves (FVCG) mechanism. Through
comparison with traditional methods, the study demonstrates that the proposed
auction method improves fairness significantly. We suggest using spectrum
sensing and integrating UAV-based networks to enhance efficiency of the LSA
system. This research employs two methods to solve the problem. We first
propose a novel greedy algorithm, named market share based weighted greedy
algorithm (MSWGA) to achieve better fairness compared to the traditional
auction methods and as the second approach, we exploit deep reinforcement
learning (DRL) algorithms, to optimize the auction policy and demonstrate its
superiority over other methods. Simulation results show that the deep
deterministic policy gradient (DDPG) method performs superior to soft actor
critic (SAC), MSWGA, and greedy methods. Moreover, a significant improvement is
observed in fairness index compared to the traditional greedy auction methods.
This improvement is as high as about 27% and 35% when deploying the MSWGA and
DDPG methods, respectively.
