Performance Investigation of IEEE802 : 11e for Industrial Wireless Network

The advantages of using IEEE 802.11-based Wireless Local Area Networks (WLAN) in industrial automation applications are substantial and include: mobility, ease and speed of installation, flexibility and costs. But wireless applications for industrial automation applications have rigorous requirements on quality of service (QoS) for the transmission of real-time critical process data. IEEE 802.11-based WLANs, which were initially designed only for best effort traffic, did not provide any QoS support for this kind of traffic. Therefore the IEEE 802.11e standard amendment was introduced and ratified in 2005. It defines the concept of a Hybrid Co-ordination Function (HCF) at the MAC layer for medium access control. HCF is a combination of HCF Controlled Channel Access (HCCA) with parameterized quality of service (QoS) and Enhanced Channel Access (EDCA) with prioritized QoS. The contemporary work deals with the performance evaluation of HCCA for industrial wireless network. A HCCA simulation model has been implemented using OPNET modeler. The simulation results are compared with EDCA in terms of delays for various scenarios