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Factory networks are typically implemented using dedicated network protocols due to their strict accuracy and latency requirements. However, these protocols tie the factory to specific equipment vendors, making it difficult to introduce other protocols. In response to this challenge, we propose a novel architecture to build a full software-defined factory network by softwarization of industrial Ethernet protocol functions, implementation of a motion control application in a general language, and control of the data plane from the network controller. We demonstrate advanced motion control from a software-defined control system utilizing an industrial Ethernet protocol on a general-purpose server and verify the effectiveness of the proposed architecture. Our proposal makes it possible to control various industrial devices from different vendors without changing applications by mediating the data stored in various protocols through drivers for each protocol. Our experimental findings demonstrate that the PROFINET software-based motion control system can be successfully implemented. The results also show that the proposed architecture can achieve successful motor control within 11.5 s by utilizing the delay compensation method.

Beyond 5th generation (5G) and 6th generation (6G) mobile systems require not only low latency but also low jitter for deterministic services such as remote operation. Since remote operation requires high-definition video streaming in the uplink, the uplink transmission performance will become more important. However, current new radio (NR) mobile systems cause jitter in the uplink traffic of the mobile backhaul (MBH) network because of the radio transmission schemes such as downlink/uplink separation of time division duplexing (TDD) and medium access control (MAC) service data unit (SDU) concatenation to compose transport blocks. Thus, we propose MBH uplink jitter reduction techniques with optical-wireless cooperative control. Our proposed techniques execute traffic shaping at a router in the MBH network to reduce uplink jitter. The shaping rate that reduces jitter while minimizing latency increase is calculated with mobile scheduling information forwarded from a next generation node B (gNB) via an extended cooperative transport interface (eCTI). The eCTI provides an interface between gNBs and network equipment to achieve optical-wireless cooperative control. In this paper, we experimentally validate our proposed jitter reduction techniques through a combination of simulations for radio transmission and experiments with a shaper prototype we developed. The results regarding end-to-end (E2E) jitter performance indicate that the proposed techniques reduce the maximum jitter by 88%, from 1.1 ms to $137 ~\mu \text{s}$ .

With the rapid spread of Internet of Things (IoT) services, the number of sensor devices has exploded, and the complexity of managing sensor devices has become a problem. To solve this problem, a metadata-based approach that uses the unique environmental information associated with each device for its management is being developed. This paper focuses on metadata collection for device management and control, and proposes a new collection method that uses low-layer communication while not modifying the existing protocol. Our proposal utilizes the extended area of the probe request (PRQ) frame of IEEE 802.11, which is a layer-2 protocol, to collect metadata. This makes it possible to achieve stable operation even on inexpensive and resource-limited IoT devices, and to realize metadata collection with low communication overhead and power consumption. It is shown to reduce the load on the central processing unit (CPU) and reduce power consumption compared to Internet Protocol (IP) -based metadata collection (layer-3 protocol and above). In addition, in terms of time sensitivity, the collection delay at the time of rising from deep sleep is reduced by 89.8% compared to IP-based techniques. Furthermore, as a benefit of low-layer collection, it enables periodic metadata collection in the background regardless of network connection above the IP layer. To demonstrate this benefit, an example of applying metadata collection to device management is prototyped and its feasibility is experimentally confirmed.

In the remote motion control of IoT devices, the delay adversely affects control performance. In our access edge concept, in which motion control is performed from a central office, the delay becomes large due to Dynamic Bandwidth Allocation (DBA) when the Passive Optical Network (PON) is adopted as the access system. No existing motion control method considers the delay changes of the DBA algorithm. We rectify this omission by proposing a novel real-time and high-precision motion control method that links the PON device and the controller. The proposed method can improve the control performance while maintaining the bandwidth utilization efficiency without changing the DBA delay specified to meet the requirements. In the proposed method, the delay in the PON system is calculated by using a delay model based on the setting parameter received from the communication device, and is used for delay compensation control. An experiment shows that, unlike the conventional method which becomes unstable and fails to realize control, the proposed method achieves high resolution control within 4 s, which demonstrates the feasibility of motion control for factory automation using edge computing in PON systems.