I. Introduction
Wireless sensor networking technologies have evolved significantly, and industrial sector is one of the beneficiaries. Communication technologies, such as Zigbee, Bluetooth low energy, and Internet Protocol version 6 over low-power wireless personal area network have also helped wireless sensor networking technologies to be adopted in the industrial environment [1]. The deployment and use of wireless sensor networks (WSNs) and wireless sensor actuator/actor networks (WSANs) in industries make it possible to optimize the production line with better quality management, energy efficiency, fault prediction, product planning, and resource prediction. When data are collected from different sensors, actuators, and machines within an industrial environment and the access and control of the data and the devices generating it are enabled through the Internet, then such a scenario is called Industrial Internet of Things (IIoT). While the Internet of Things (IoT) is providing Internet access to any “thing,” the IIoT restricts the “things” to the scenario of industry. Similar to the concept of IIoT, Industry 4.0 refers to the current fourth generation of industry focusing on the manufacturing industry scenario only that is a subset of IIoT. Fig. 1 shows the concept of IIoT and Industry 4.0 within IoT.