# An Energy Efficient Routing Approach for Cloud-Assisted Green Industrial IoT Networks  
[PERSON]  
1 Division of Computer Science and Engineering, Jeonbuk National University, Jeonju 54896, Korea; [EMAIL_ADDRESS]  
[PERSON]  
1 Correspondence: [EMAIL_ADDRESS]; Tel. : +82-10-341-25323115661  
systems, manufacturing, factory automation, supply chain management, and utilities. In short, the IIoT concept focuses mainly on improving efficiency, safety, and production [3]. Moreover, various industrial domains can greatly benefit from IIoT by saving time and cost through smart notification and alerts, early malfunction detection, predictive maintenance, improved safety, and performance monitoring. Furthermore, the cloud-assisted IIoT system enables the real-time performance analytics of the industrial system remotely, thereby optimizing the outcome. It is emphasized that the realization of IoT systems in any industrial domain will exploit a large number of smart objects for enhancing the operation by enabling the accessibility and acquisition of a large amount of data. The data generated from a large number of connected smart objects is vital to the IIoT ecosystem as it can provide critical information for being industries more efficient, smarter, and sensible. To realize this, embedded devices, sensors, and actuators cover most of the critical areas and instruments, where these devices sense the environment, monitor the conditions, and collect the information to share between devices and with the control system. Considering the simplicity of these devices, the collected information can be treated by a central computing infrastructure, for instance, a cloud-based data center [4]. In the industrial networking settings, the low power and lossy networks (LLNs) are widely used for different applications and services such as condition monitoring, process automation, and environment sensing. Generally, the applications under condition monitoring cover the monitoring of mechanical, structural, and human conditions. Whereas, the industrial applications for environment monitoring include the problems of noise, water, air, temperature, humidity, etc. Likewise, the process automation applications cover the information regarding service delivery, including resource availability, current stock, demand, and supply process, etc. [5]. In this way, IIoT connects various objects to facilitates the complex tasks of monitoring, controlling, and automating industrial activities and provides efficient services with a new opportunity. The industrial wireless network can be seen as a core physical infrastructure for industrial information systems (IIS), and collect data to support engineers and operators in the decision-making and crisis management. In IIoT networks, the generated data is large and important such as real-time monitoring, supervision, and control instructions, which need to be delivered timely and reliably. In such a circumstance, it indicates not only the presence of several traffic types within the network but also the different quality of service (QoS) requirements [6]. Moreover, IIoT networks may provide multiple applications and services, some of which are not only time-critical but also delay-tolerant. In this context, IIoT networks may face significant challenges to ensure the stringent requirements of industrial applications such as high reliability, energy efficiency, low communication cost, and low latencies. On the other hand, industrial wireless networks differ from traditional wireless networks in several ways. The devices of IIoT have limited resources in terms of energy, computation, memory, and wireless link. In the IIoT environment, with the help of other nodes (i.e., intermediate nodes or relay nodes), the source node transmits its data packets to the destination node (i.e., gateway or sink) due to the limited transmission range [7]. These characteristics bring new challenges to improve energy efficiency and to design a reliable routing protocol.