Decentralized Auction for Blockchain-Based Dynamic Spectrum Sharing in 6G Networks

The traffic of mobile communication grows exponentially while the available spectrum resources are extremely limited. Fortunately, dynamic spectrum sharing (DSS) is a promising technology to increase spectrum utilization. However, 6G is composed of different networks and owned by different operators. The operators are unwilling to share spectrum resources for free. Moreover, privacy and security concerns from operators increase the difficulty of spectrum sharing. How to achieve an effective and safe DSS among the operators is a challenge. To address the challenge, this paper proposes a blockchain-based DSS (BDSS) framework for 6G heterogeneous networks. Firstly, BDSS is enabled with spectrum resource auctions, where an incentive mechanism is designed to motivate more operators to participate in auctions. To guarantee the security issue, the auctions are deployed on smart contracts of blockchain, which allows untrusted operators to make credible transactions for spectrum resources. Under the proposed framework, a decentralized multi-round auction (DMRA) algorithm is designed to maximize spectrum utilization while ensuring system utility. The system and auction method we propose are entirely decentralized. A prototype system based on Hyperledger Fabric is utilized to validate the effectiveness of the proposed system. Simulation results show that compared with the existing schemes, our proposed DMRA algorithm can increase the system utility and spectrum utilization by $37 \%$ and $12 \%$ on average, respectively.