An enhanced MAC to increase reliability in redundant Wi-Fi networks

摘要

Wireless communications are becoming increasingly appealing for many application areas in industrial environments, including control systems at the shop-floor. IEEE 802.11 resembles Ethernet closely and, in the newest versions, it manages to provide similar throughput. Unfortunately, it fails in ensuring a comparable degree of reliability, mostly because its physical layer is quite sensitive to interference and disturbance. To overcome these limitations, very interesting solutions have appeared recently that layer a redundancy protocol above conventional Wi-Fi equipment. In this paper, a new approach is introduced and evaluated, which enhances reliability further by making redundant wireless adapters share information about the outcome of acknowledged transmissions. Doing so decreases both transmission latencies and the amount of lost packets.