High-Performance Industrial Wireless: Achieving Reliable and Deterministic Connectivity Over IEEE 802.11 WLANs

Communication for control-centric industrial applications is characterized by the requirements of very high reliability, very low and deterministic latency and high scalability. Typically, IEEE 802.11-based wireless local area networks (WLANs), also known as Wi-Fi networks, are deemed ineligible for industrial control applications owing to insufficient reliability and non-deterministic latency. This paper proposes a novel solution for providing reliable and deterministic communication, through Wi-Fi, in industrial environments. The proposed solution, termed as <inline-formula><tex-math notation="LaTeX">$\mathsf{HAR}^{\mathsf{2}}\mathsf{D-Fi}$</tex-math></inline-formula> (<underline>H</underline>ybrid channel <underline>A</underline>ccess with <underline>R</underline>edundancy for <underline>R</underline>eliable and <underline>D</underline>eterministic Wi-<underline>Fi</underline>), adopts hybrid channel access mechanisms for achieving deterministic communication. It also provides temporal redundancy for enhanced reliability. <inline-formula><tex-math notation="LaTeX">$\mathsf{HAR}^{\mathsf{2}}\mathsf{D-Fi}$</tex-math></inline-formula> implements different medium access control (MAC) designs that build on the standard physical (PHY) layer. Such designs can be classified into two categories: (a) MAC designs with pre-defined (physical) time-slotted schedule, and (b) MAC designs with virtual time-slotted schedule. Performance evaluation, based on analysis and system-level simulations, demonstrates the viability of <inline-formula><tex-math notation="LaTeX">$\mathsf{HAR}^{\mathsf{2}}\mathsf{D-Fi}$</tex-math></inline-formula> for control-centric industrial applications.