A Simulation Case Study of the new IEEE 802.11e HCCA mechanism in Industrial Wireless Networks

The advantages of using IEEE 802.11-based wireless local area networks (WLAN) in industrial automation applications are substantial and comprise a higher flexibility, greater mobility and reduced maintenance costs. However, the currently used medium access mechanism makes WLANs non-deterministic and hence not suitable for industrial real-time traffic. The new amendment IEEE 802.11e introduces the HCF controlled channel access (HCCA) for parameterized QoS and the enhanced distributed channel access (EDCA) for prioritized QoS. This paper evaluates the performance of the HCCA in an industrial automation network with real-time requirements by means of a simulation case study with the network simulator OPNET and compares the results with the EDCA in terms of latency in various scenarios.