  The innovation provided by network virtualization in 5G, together with
standardization and openness boosted by the Open Radio Access Network (O-RAN)
Alliance, has paved the way to a collaborative future in cellular systems,
driven by flexible network sharing. Such advents are expected to attract new
players like content providers and verticals, increasing competitiveness in the
telecom market. However, scalability and trust issues are expected to arise,
given the criticality of ownership traceability and resource exchanging in a
sharing ecosystem. To address that, we propose integrating blockchain
technology for enabling mobile operators and other players to exchange RAN
resources (e.g., infrastructure) in the form of virtual network functions (VNF)
autonomously and dynamically. Blockchain will provide automation, robustness,
trustworthiness, and reliability to mobile networks, thus bringing confidence
to open RAN environments. In particular, we define a novel O-RAN-based
blockchain-enabled architecture that allows automating RAN sharing procedures
through either auction or marketplace-based mechanisms. The potential
advantages of the proposed solution are demonstrated through simulation
results. The used simulation platform is openly released.
