A Clustered ZC in Cloud Computing Empowered by Blockchain

A zone controller (ZC) plays a vital role in urban rail transit, which is responsible for the safe separation of the running trains within its control area. If a ZC fails, the operation of trains will be severely disrupted. To avoid single point failures and provide safer services, we propose a clustered ZC (C-ZC) which utilizes the technologies of cloud computing and blockchain. A consensus algorithm, proof of timer hash (PoTH), is proposed to realize the decentralized C-ZC service. The performance of the PoTH and the C-ZC service are analyzed and verified through simulation. Based on the simulation results, it is can be concluded that the PoTH is superior to other consensus algorithms in terms of latency. It is proved that the C-ZC can satisfy the requirements of communication-based train control system (CBTC) system on both latency and the number of trains being served, achieve higher safety and reliability simultaneously.