Research Of Routing Algorithm Based On Link Quality For Industrial Wireless Networks

With the rapid development of network technology, the traditional field of industrial control ha s also been turned upside down. The tide of wireless,which is penetrating into the industrial fiel d,leads the rapid development of industrial wireless communications technology.Industrial wire less communication technology is used for the information exchange between devices, and it’s expan ding and improving the functionality of the existing industrial communications technology in the dir ection of industrial applications. Industrial wireless network WIA-PA (Wireless Networks for Industr ial Automation-Process Automation) is an industrial wireless network technology with independen t intellectual property of China. It is the joint research and development which is created by the Ch inese Academy of Sciences, Shenyang, Southwest University and more than 10 units in the sup port of the National 863 Project. WIA-PA is a wireless network system based on the IEEE802.15.4 s tandard,used for industrial process measurement, monitoring and control system. WIA-PA is charac terized by a close, low complexity, low power, low-cost two-way wireless communications technolo gy. There is a strong potential and a prospective market to develop and improve for WIA-PA in the field of industrial control.WIA-PA technology uses Mesh and Star two-tier topology. Mesh layer is composed of gatewa y and routing equipment while the Star layer is constituted by routing equipment and field devices. T he network layer of the field device does not have routing capabilities, and all the routing nodes i n WIA-PA network are almost in the same position. This feature is also great similarity with the A d Hoc network. WIA-PA technology is an emerging technology, and the research of its routing techn ology is less. However, Ad Hoc Networks have more sophisticated routing studies after years of rese arch and application.In terms of the similarity of the WIA-PA and Ad Hoc Networks, this paper s tart with the Ad Hoc network routing protocols and make an analysis and comparison of the tra ditional routing protocols. On this basis, it combines with the characteristics of the WIA-PA net work to improve the shortage applied in WIA-PA and proposes an appropriate routing algor ithm for WIA-PA.This paper first introduces the thesis work in the background, significance, and the work. At th e same time, it gives a detailed description of the structure and characteristics of industrial wireles s network WIA-PA.WIA-PA is mainly used in the field of industrial control.It requires a higher r eliability and instantaneity on network. Actually, the industrial environment is very harsh. The co mplex and diverse confounding factors affect the quality of network links. Link quality is very impo rtant on the efficiency and reliability of network communication. Therefore in the process of desig ning routing protocols, putting link quality into consideration is a good protection for the reliabilit y of the network. At present, the main wireless network link quality measurement methods include t he ETX, the SNR, the LQI and the WMEWMA. This article analyzes link quality measurement met hods and the requirements of designing WIA-PA routing protocols, and starts with routing pr otocols which are based on link quality that had been mentioned in front page to study the Ad-Hoc routing protocols which is similar to the WIA-PA routing protocols in the structure.In-depth analysis of the Ad-Hoc network routing protocols used in WIA-PA,we select the AO DV routing algorithm to study.Because AODV routing algorithm only use the minimum nu mber of hops as a basis for routing,that can’t meet the reliability requirements of WIA-PA .So we improved a new routing protocol LQBA(link quality for WIA-PA based AODV),whi ch is based on AODV and considered the link quality. Finally,we use NS2 simulation platf orm to analysis the routing algorithm in throughput, packet loss ration and the average netw ork energy consumption.The results show that LQBA routing algorithm improves network th roughput and reduce the packet loss rate compared with AODV. Also it can apply in the W IA-PA well and protect the reliability of the network communication efficiently.