www.seipub.org/ie Information Engineering (IE) Volume 1 Issue 1, December 2012 8 Analysis of Industrial Networks Using Different Wlan Standards Qutaiba Ali 1 , Enaam Khuder 2 Faculty Computer Eng. Dept., Engineering College Mosul University, Iraq Email: 1 qutaibaali@uomosul.edu.iq; 2 enaam_kheder@uomcoe.org Abstract Nowadays, Industrial Ethernet and Wireless Local Area Network (WLAN) have entered strongly into the fields of control and automation. Data acquisition products offer many options regarding the networking of these devices using the above techniques. This paper analyzes the performance of different Industrial WLAN standards (IEEE802.11b, IEEE802.11a and IEEE802.11g) by means of simulation using OPNET package as the network simulation tool. Detailed simulation models of the industrial nodes (sensors & actuators) were built and the effect of different parameters such as WLAN speed, WLAN modes, WLAN topology, traffic intensity…etc. on the system performance were examined. The goal of this study is to determine the maximum limits of the system in order to serve as a real time system suitable for various control and automation tasks. Keywords IEEE802.11WLAN; Industrial Ethernet; Delay; Throughput; Real‐Time Data Introduction For the last few years, wireless communications have been pervading many application areas and are affecting an ever‐increasing number of aspects of everyday life. Compared to its wired peers, wireless LANs have advantages like low cost, fast setup, flexible configuration, user mobility support, etc. During recent years the IEEE 802.11 WLAN standard has been widely deployed as the most preferred wireless access technology [M. Akbar]. The introduction of IEEE 802.11 standard provides basis for interoperability between different products. In addition, the 11 Mbps of IEEE 802.11b and 54 Mbps of IEEE 802.11a offer high speed connections like Ethernet [X. James Dong]. WLAN works without limitation of cabling using either infrared light (IR) or radio frequency (RF) as medium [P. Simacek]. The advantages that wireless technologies offer, lead to various number of possible applications and services, which may be used in industrial fields. Intensive research proceeds at IP based controlling over wireless networks, which will together with Internet relieve remote control [P. Simacek]. At present, wireless communications are used in industrial environments mainly to enable simpler and more cost‐effective maintenance and diagnostics functions [G. Cena][ G. Cena][A. Willig]. For instance, low‐cost 802.11 access points are sometimes introduced in control networks used at the factory shop‐floor to enable diagnostic/ management tools to be temporarily connected that are needed, for example, to reconfigure the control software or change operating parameters[G. Cena]. WLAN was not originally designed for industrial applications and suffers from the same defections. Implementation of new standards such as 802.11a or 802.11g can rapidly enhance WLAN usability in real‐ time considerations ‐ the new norms introduce faster transmission technologies. A number of technical solutions based on either standard or proprietary wireless communications have already been introduced in automated plants and machines, which take advantage of their features to solve peculiar problems for particular types of applications [P. Simacek]. This paper is investigating performance of various 802.11 WLANs standards with respect to their possible use in industrial environments. We focused on end‐to‐ end delay and throughput of each standard to discover critical values of these parameters and we studied the effect of non real‐time data in order to be able to predict the performance of WLAN standards in industrial applications.