Research On Network Topology Control Of Industrial Wireless Networks Based On DRNG

Wireless sensor network as a significant influence one of the technologies in the 21st century, it become a hotspot in the research of automation field. Industrial wireless sensor network is based on the traditional wireless sensor network, the technology not only has low-power, low-cost and real-time characteristics and so on in wireless sensor networks, but also high demand for the reliability of the industrial site. It makes sure that device control and data acquisition in the industrial control field are able to meet the needs of industrial production, and it can manage the automation monitoring and operations in industrial control process.WIA-PA(Wireless Networks for Industrial Automation-Process Automation) with independent intellectual property rights is an industrial wireless networking standard for industrial process automation which is researched and developed by the leader-CAS Shenyang Institute of Automation,and it became one of the international industrial wireless communication standard in 2008. WIA-PA standard propose industrial wireless network communications, high reliability, real-time, ultra-low power and a series of challenging research topic for the complex environment in the industrial field. In the site of industrial control, the basic and important task is to ensure industrial security and reliable operation in the production process, so it must be able to ensure high reliability of wireless networks in the use of industrial wireless network substituting the traditional facilities of industrial. WIA-PA has a double-layer network protocol which includes mesh network layer and star network layer for the realization of industrial wireless network routing node of the distributed management and centralized industrial field device control. Star network can reduce industrial data transmission and control complexity by centralized management, and mesh network can improve the reliable transport by high-density nodes. In other side, node density is too high will cause more complex of the network topology in mesh networks with increasing the interference of cluster node, reducing the quality of data transmission and the reliability of the network, impacting the network transmission performance. This paper focus on optimization of mesh network, reducing interference of cluster-nodes and improving the reliability of network transmission for Structural characteristics of mesh networks in WIA-PA.This paper introduces the three main industrial wireless standard, meaning and methods of traditional topology control, researches on DRNG algorithm based on adjacent graph with the features of WIA-PA network. Because DRNG algorithm can case rapid death of the sending node and low quality neighbor problem, the paper designs a algorithm LR-DRNG which base on node degree, link quality indication and the residual energy. The main idea of LR-DRNG algorithm is to adjust power of the sending node by node degree for improving the send node death fast by the maximum power in DRNG algorithm.this way can reduce the energy of nodes transmitting. The algorithm use the link quality indication as edge weight for improving DRNG simple algorithm using euclidean distance as the weight of a neighbor node selection, it can improve the reliability of the node transmission. The algorithm use the method of residual energy in neighbor node selection for extending the network life, and use the strategy of node sleep for reducing communication interference between nodes, increasing network reliability and making up for node failure. It should be to extend the network lifetime and improve the network transmission reliability by mesh network topology control with LR-DRNG in WIA-PA.This paper introduces three common simulation tools and use NS2 simulation tool for comparing the network performance with DRNG and LR-DRNG form network average packet loss rate, the average network delay, throughput of network and network lifetime. From NS2 simulation result, the improving algorithm takes a better performance in reducing network packet loss and network delay, improving the network throughput and extending the network lifetime, it also can protect the low residual energy nodes. The simulation results show that LR-DRNG can reduce industrial wireless network 12.5% of packet loss rate. The average network delay is relatively stable and lower than DRNG algorithm. It can extend the industrial wireless network 19% of life cycle.The improved algorithm is effective to WIA-PA.