Grouping TDMA access for industrial wireless sensor networks with multiple access points

Addressing the extremely high reliability is a critical problem of wireless control system in actual industrial applications. In this paper fully considering the characteristics of the wireless network transmission and industrial automation application, a grouping TDMA access approach based on multiple access points is proposed. The main idea is that: redundant multiple access points are applied in communication to improve the system reliability, multiple time synchronizations are made because of beacon frames of multiple access points to improve the accuracy, and ACK is replied by reliable access point to reduce retransmission and improve resource utilization. Finally, a corresponding access device is designed and implemented. Experiments show that it can meet the harsh requirements for the communication in control loops and demonstrates the effectiveness of the proposed approach.