Coexistence Model of IEEE 802.11b and 802.15.4 for Industrial Applications in Oil or Gas Station

Abstract-- The coexistence between IEEE 802.11b Wireless Local Area Network (WLAN) and IEEE 802.15.4 Wireless Sensor Network (WSN) is a very sensitive issue while dealing with heterogeneous wireless network standards forming a single network. IEEE 802.15.4 supports low data rate, low power and IEEE 802.11b operates with higher data rate. IEEE 802.15.4 sensor devices are very much vulnerable to interference with IEEE 802.11 WLAN standard devices. Both these standards operate at Industrial, Scientific and Medical (ISM) band of 2.4 GHz. WLAN and WSN need to co-exist to serve as a reliable communication network in many real life scenarios like Oil & Gas fields, battle fields etc. The wireless communication skeleton makes the industrial monitoring and management control easy as compared to a wired system. In many industrial applications, WSN data is very much crucial and this kind of data should be kept unaffected from any interference that may be caused by any WLAN devices nearby. In this paper, efforts have been made to resolve the various problems which arise due to the coexistence of WLAN and WSN standards operating at the same frequency bandwidth. We focus on the issue of protecting WSN from WLAN interference. It has been attempted by selecting appropriate operating ranges for different devices based on analyses of various issues which form the essential basis for the conventional packet collision avoidance mechanisms to minimize the interference effect for measuring various set of parameters. Our model has been simulated with a sample test-bed and results are obtained for different WLAN packet sizes which help to understand the impact of WLAN on WSN