A Survey on Industrial Internet of Things: A Cyber-Physical Systems Perspective <s> C. M2M FOR I-IOT <s> In industrial automation, the state of process control could be monitored by spatially distributed sensors and 5G machine-type communication (MTC) enabled industrial Internet of things (IIoT). Thus, ultra-reliable MTC and high-accurate state estimation play important roles for ensuing system stabilization. However, it is challenging due to complex industrial wireless environments and limited communication resources. To address this issue, this paper first presents a transmission-estimation codesign framework to lay down the foundation for guaranteeing the prescribed estimation accuracy with limited communication resources. Under this framework, a hierarchical transmission-estimation approach is proposed to improve the transmission reliability and estimation accuracy according to system dynamics. The proposed approach is then optimized by formulating a constrained minimization problem, which is mixed integer nonlinear programming and solved efficiently with a block-coordinate-descent-based decomposition method. Finally, simulation results demonstrate that the proposed approach has superiorities in improving both the estimation accuracy and the energy efficiency. <s> BIB001 </s> A Survey on Industrial Internet of Things: A Cyber-Physical Systems Perspective <s> C. M2M FOR I-IOT <s> Communication networking leverages emerging network technologies such as topology management schemes to satisfy the demand of exponentially increasing devices and associated network traffic. Particularly, without efficient topology management, Machine-to-Machine (M2M) communications will likely asymmetrically congest gateways and eNodeBs in 3rd Generation Partnership Project (3GPP) Long-Term Evolution (LTE) and Long-Term Evolution Advanced (LTE-A) networks, especially when M2M devices are massively deployed to support diverse applications. To address this issue, in this paper, we propose a 3D Topology Optimization (3D-TO) scheme to obtain the optimal placement of gateways and eNodeBs for M2M communications. By taking advantage of the fact that most M2M devices rarely move, 3D-TO can specify optimal gateway positions for each M2M application, which consists of multiple $M$ 2 $M$ devices. This is achieved through global optimization, based on the distances between gateways and M2M devices. Utilizing the optimization process, 3D-TO likewise determines optimal eNodeB positions for each M2M application, based on the distances between eNodeBs and optimal M2M gateways. Our experimental results demonstrate the effectiveness of our proposed 3D-TO scheme towards M2M communications, with regard to throughput, delay, path loss, and packet loss ratio. <s> BIB002 </s> A Survey on Industrial Internet of Things: A Cyber-Physical Systems Perspective <s> C. M2M FOR I-IOT <s> Current forecasts predict that the Industrial Internet of Things will account for about 10 billion devices by 2020. Simultaneously, unlicensed low-power wide area networks are gaining momentum due to their low cost, low power, and long range characteristics, which are suitable for many IIoT applications, in addition to the usage of unlicensed bands. In this article, a solution is proposed to seamlessly integrate LoRaWAN, an open and standardized LPWAN technology, with 4G/5G mobile networks, thus allowing mobile network operators to reutilize their current infrastructures. This proposal is transparent to LoRaWAN end devices and to the EPC, since only the LoRaWAN gateway needs to be modified. The gateway acts as an evolved Node B from the core network perspective, implementing part of the eNB protocol stack. All data packets transported over the core network are both encrypted and integrity protected, hence achieving end-toend security. As a proof of concept, this solution has been implemented and validated with an open source EPC. <s> BIB003 </s> A Survey on Industrial Internet of Things: A Cyber-Physical Systems Perspective <s> C. M2M FOR I-IOT <s> With the advance of Internet of Things and the support of a diverse array of smart-world applications, the number of Machine-to-Machine (M2M) devices has continued to grow at an accelerated rate. This significant and unchecked increase poses enormous challenges to both M2M infrastructure and the coexistence of M2M applications. In this paper, we model the traffic arrival patterns of time-driven, event-driven and loop-driven M2M applications, and propose a novel dynamic rate adaptation (DRA) scheme to obtain an optimized service rate distribution among a mixture of diverse M2M applications. DRA introduces real-time monitoring of M2M traffic arrival rate, building on which a service rate distribution between M2M applications can be incrementally adjusted moment to moment, through the use of the mean value theorem of integrals (MVTI) and generalized processor sharing (GPS). Via a combination of both theoretical analysis and extensive performance evaluation, we have validated the effectiveness of our proposed DRA scheme. Our experimental results demonstrate that DRA can significantly improve M2M communications performance with respect to throughput, delay, and energy consumption. In addition, we extend our proposed DRA scheme from the perspective of Device-to-Device (D2D) communications and further discuss the resilience of DRA. <s> BIB004
Communication in I-IoT is different from the communications for consumers, even in the case of consumer IoT. Specifically, I-IoT devices usually collect and transmit data via uplinks (UL)  , a type of communication identified as machine-type communications. Indeed, there are some existing research efforts toward the study of M2M communication in I-IoT applications BIB004 , BIB001 , BIB002 . For instance, the codesign of both control system and network transmission is one effective approach to leverage M2M for I-IoT. In this direction, Lyu et al. BIB001 proposed the co-design of state estimation and wireless transmission in 5G machine-type communication enabled I-IoT systems to improve the accuracy of estimating state parameters over resource constrained wireless networks. Their approach consists of hierarchical state estimation and two-stage transmission that can adapt to system dynamics. By using the three-dimensional framework in Figure 7 , this work can be mapped to cube <Monitoring, PA, Reliability>. In addition, Navarro-Ortiz et al. BIB003 proposed the integration of the standardized low-power wide area networks (LoRaWAN) and 4G/5G. This integration leverages the benefits of LoRaWAN and the network infrastructure provided by 4G/5G to satisfy the requirements of massive machine-type communications (e.g., low power, long range, and low bandwidth). Compared to the LTE-WLAN integration, the integration of LoRaWAN and 4G/5G can satisfy the requirements of M2M for I-IoT. In addition, the LoRaWAN and 4G/5G integration requires minimal changes to the existing mobile networks, needing only the modification of the LoRaWAN gateway (i.e., modifying gateways to eNodeBs to the 4G/5G EPC and implementing the eNodeB protocol stack). This was tested as a proof-of-concept in an experimental testbed with promising results.