A Cross-Network Clock Synchronization Scheme With Low Complexity for Industrial Internet of Things

摘要

In Industrial Internet of Things (IIOT), devices possess a tight timing relationship between each other so that precise clock synchronization is an important technology for networks to function properly. In this paper, we investigate the clock synchronization problem of IIOT in a heterogeneous industrial network which consists of two types of subnetworks: industrial wireless field network and wired backhaul network. Based on border gateway forwarding, a cross-network clock synchronization scheme with low complexity for IIOT is proposed. The industrial wireless field network and the wired backhaul network can get synchronized simply via software and without the requirement of hardware synchronization unit. Moreover, the mixed transmission of time synchronization data and network protocol data is supported. The cross-network synchronization scheme is designed in detail and implemented on an experimental platform. Test results show that the proposed method can meet the requirement of cross-network clock synchronization with low complexity and is convenient for unified management and Internet Protocol (IP) transmission of the networks.