BC-RAN: Cloud radio access network enabled by blockchain for 5G

Cloud radio access network (C-RAN) supports the explosion of Internet of Things (IoT) applications and the demand for massive access in 5G networks. However, centralized access of trustless operators causes severe malicious insider threats, such as maliciously tamper and accidentally delete data. Blockchain, a traceable and non-tamper distributed ledger maintained by all nodes, has been considered as a feasible method to overcome these threats, while the size of the blockchain network is limited by practical byzantine fault tolerance (PBFT) consensus algorithm where the participants, the nodes who participate in consensus algorithm, bring heavy communication traffic. In this paper, we first propose a C-RAN enabled by blockchain (BC-RAN) for 5G with PeerTrust-based PBFT (Trust-PBFT) consensus algorithm to prevent the malicious insider threats and scale up the size of the blockchain network. We also propose a tri-chain structure of blockchain to divide transactions into three categories for storage to facilitate traceability. The algorithm calculates the trust value of each node, and those with high trust values will be elected to be the participants of PBFT. Simultaneously, due to the introduction of PeerTrust, another benefit is to improve the fault tolerance performance efficiently. Besides, an adjustment mechanism is designed-newly and implemented in the algorithm to impede effects produced by the malicious nodes in the blockchain network. Finally, several simulation experiments are designed to evaluate and compare the fault-tolerance performance and scalability of Trust-PBFT.