Data Transmission Scheduling Of WIA-PA Wireless Network

Large-scale and precise production is the development trend of Modern industrial, this phenomenon has put forward higher requirements for ICS (Industrial control system), and it requires the control system to provide timely control and data information service. Control Network is responsible for the industrial data transmission task of ICS, and it’s the basic guarantee to realize digital control. The Wireless control had seized attention of vast researchers due to its flexibility and low cost. The main research content of this article is the data transmission performance of wireless control network, according to the different triggered of signal in the network data transmission can be divided into two types:1) Scheduling-Based protocol for periodic data, 2) Contention-Based protocol for aperiodic data. Periodic data of control system are mostly the process information of production, this data needs high reliability and real-time performance guarantee. Wireless standard employ TDMA GTS (Guaranteed Time Slot) to ensure the conflict-free transmission of nodes data. We use WIA-PA wireless standard as our research object and the main purpose of this study is to optimize the data transmission performance of wireless network. Firstly, a multi-hop grading model was built through the limitation of transmission distance of wireless nodes; secondly, using graph coloring algorithm to eliminate conflict of data transmission; at last, a genetic algorithm with double-layer encoding was put forward to optimize transmission performance by combine Link Scheduling and Time-Slot Assignment synchronous.ICS can handle more information now by the development of computer technology, this lead to that the number of aperiodic data rising in control network. Different with periodic data, researchers pay more attention to the utilization of network and the simplicity of transfer protocol. In this article, two common Contention-Based protocol was choose to check transmission performance in aperiodic data research, they are CSMA/CA protocol and CCA-Embedded TDMA protocol. Mathematical models were built to fitting this protocols, and then simulation analyze based on this model were given to describe how network data flow and back-off time influence aperiodic data transmission performance such as throughput and data delay.