Performance Optimization and Improvement of ISAC-Enabled Industrial IoT Based on Intelligent Sharding Blockchain

The security and reliability risks of industrial sensors have constrained the integration of the integrated sensing and communications (ISAC) and the Industrial Internet of Things (IIoT). Although blockchain can protect the security and reliability through hash verification mechanisms, there are numerous challenges in the existing systems, such as the scalability bottleneck, high computational power consumption of consensus protocols and limited computational resources of industrial sensors. To address these problems, an intelligent sharding blockchain framework is proposed, in which the reputation mechanismbased intelligent sharding and the adaptive consensus protocol switching are utilized to enhance the decentralization, security and scalability of blockchain. Considering the higher requirements of computational power of the sharding blockchain, a cloud-edge-end collaborative computing framework is introduced, in which the parallel computational offloading and the Terahertz communication technology are utilized to enhance the cooperation between the cloud and edge networks. Furthermore, due to the dynamic characteristic of industrial sensors and industrial data, we formulate the optimization problem as a Markov decision process (MDP), which is solved via the Proximal Policy Optimization (PPO) algorithm. Simulation results show that our proposed scheme can minimize total latency and maximize transaction throughput while guaranteeing the safety as well as decentralization of the IIoT systems.