802.11n Performance analysis for a real multimedia industrial application

• We have evaluated experimentally the timing behavior of 802.11n.
• We have evaluated the influence of EDCA and bit rate algorithm.
• We have analyzed that in a controlled and uncontrolled scenarios.
• EDCA could have a positive impact in all cases.
• Bit rate algorithm could have even more impact.
• An increase in multimedia performance could produce missed deadlines in control traffic.

In spite of their limitations, wireless networks are being increasingly used in industrial environments. The electromagnetic phenomena that can occur, along with the interference that may occur due to it being an open medium, mean that fluctuations in latencies are often produced. These drawbacks limit the use of wireless networks for distributed factory applications where timeliness is essential. Recent standards, such as 802.11n, offer some interesting characteristics applicable to factory automation. In particular, QoS support and a very high data rate aids their operation under non-saturation conditions, allowing their satisfactory use as an industrial network. In this paper, the potential of these networks is analyzed in a real world scenario and their performance is compared with an idealized scenario. In both cases the priorities behave as expected, however, the algorithms for an auto-rate functioning perform badly in real world situations, especially in industrial scenarios such as those analyzed here, where the mobility of sources and the interference produced by other sources produce frequent rate changes, leading to a reduction in network performance.