Research on deterministic communication of industrial wireless based on WLAN

The shortages of WLAN applied to the field of industrial control are given by analyzing the communication mechanism of WLAN. In this article, it presents a new communication method with deterministic scheduler in order to satisfy requirement of industrial wireless communication. It selects beacon interval as communication macro cycle, and pre-selects a station as the coordinated station that is responsible for the maintenance accurate clock synchronization function within the BSA. In data link layer, packets from user layer are divided into periodic packets and non-periodic packets. In terms of devices configured information beforehand, the periodic packets would be sent by fixed time clock, while the non-periodic packets would be sent when it is polled by the coordinated station, herein, we selected polling algorithm with good performance in the aspect of adaptive. This is called deterministic scheduling. The deterministic scheduling mechanism put forward in this paper provides foundation for applying WLAN to the field of industrial control, and its deterministic communication methods is compatible with other commercial WLAN well.