Age-Critical Blockchain Resource Allocation over Satellite-based Internet of Things

With the development of next generation of mobile communications, the access of massive Internet of Things (IoT) devices need a more intelligent and secure network. Blockchain has become an emerging technology due to its characteristics of decentralization, stability and transparency. Thus, the combination of blockchain and IoT has attracted the focus of researches. However, the conventional blockchain based on terrestrial network are limited to the scalability and latency. With the support of the wide coverage of satellite, satellite-based Internet of Things (S-IoT) can solve the defect of large consensus latency of blockchain in terrestrial networks. In this paper, considering the limitation of system power and to improve the freshness of information, i.e., the age of information (AoI), we propose a power allocation scheme to accelerate the blockchain consensus over the S-IoT network. Then, we derive the closed-form expressions to the latency and power consumption of blockchain consensus over the S-IoT network. Moreover, we formulate an average AoI (AAoI) optimization problem subject to the total power constraints and solve it by genetic algorithm. Simulation results show that the proposed power allocation scheme has a superior performance in terms of AAoI and throughput compared to the conventional blockchain schemes.