Abstract : The increasing number of devices in massive machine-type communication (mMTC) and the industrial Internet of Things (IIoT) requires more reliable, flexible, and intelligent communication systems with high capacity. As machines and IIoT devices are expected to be the main users of beyond 5G (B5G) and 6G networks, we should consider candidate technologies tailored for the mMTC scenario. In this paper, we propose a new paradigm of integrated sensing and communications (ISAC) tailored for sensor networks in smart factories, representing a key use case for mMTC. The ISAC for mMTC should be differentiated from radar sensing-based conventional ISACs and be capable of collaborating with other enabling technologies to enhance the performance of mMTC systems. In this context, the proposed framework enhances capabilities by introducing a packet layer, and this paper demonstrates its seamless integration into existing ISAC frameworks. To establish a novel framework for ISAC within the mMTC scenario, we focus on two major candidate technologies for B5G and 6G: private 5G and open radio access network (Open RAN, O-RAN). We present a reliable and secure sensor network leveraging private 5G infrastructure and suggest an intelligent data-driven system enabled by O-RAN architecture. Finally, we demonstrate the feasibility of the proposed framework with our testbed by showcasing the sensor data monitoring and predictive maintenance use cases for a smart factory system.
Index terms : Massive machine-type communication (mMTC), Integrated sensing and communications (ISAC), Open RAN, Private 5G, Sensor network