Blockchain Empowered Dynamic Spectrum Sharing: Standards, State of Research and Road Ahead

As the scarcity of spectrum resources, especially in mid-band (1 to 6 GHz), becomes more significant in beyond 5G and 6G era, spectrum sharing is promising to solve this problem. Various spectrum sharing approaches have been proposed and standardized, such as centralized geolocation database. The emergence of blockchain technology provides a great solution to enhance spectrum sharing technology in a decentralized way. With blockchain technology, trust can be established among multiple public or private wireless networks owned by different operators. Moreover, decentralized ledgers can reduce the number of transactions and validation processes executed by each node, thereby improving spectrum trading efficiency. In this article, we summarize the standardization progress of spectrum sharing and the application of blockchain in wireless communications. Then, we investigate the key issues encountered by blockchain-based spectrum sharing and propose potential solutions to these problems. Finally, we present future research directions for blockchain-based dynamic spectrum sharing.