NOMA-Based 802.11n for Industrial Automation

Industry 4.0 and Industrial Internet refer to the expected revolution in production, utility management and, in general, fully automated, interconnected and digitally managed industrial ecosystems. One of the key enablers for Industry 4.0 lies on reliable and timely exchange of information and large scale deployment of wireless communications in industry facilities. Wireless will bring solutions to overcome the main drawbacks of the current wired systems: lack of mobility, deployment costs, cable damage dependency and scalability. However, the strict requirements in reliability and latency of use cases such as Factory Automation (FA) and Process Automation (PA) are still a major challenge and a barrier for massive deployment of currently available wireless standards. This paper proposes a PHY/MAC wireless communication solution for FA and PA based on Non-Orthogonal Multiple Access (NOMA) in combination with the 802.11n standard. The communication system proposed aims at delivering two different sets of services. The first service class is composed of Critical Services (CS) with strict restrictions in reliability and latency. The same communication system should convey also a second group of services, referred as Best Effort (BE) with more relaxed boundary conditions. The proposal theoretical background, a detailed transmission-reception architecture, the physical layer performance and the MAC level system reliability are presented in this paper. The solution provides significantly better reliability and higher flexibility than TDMA systems, jointly with a predictable control-cycle latency.