A Survey on Industrial Internet of Things: A Cyber-Physical Systems Perspective <s> IV. NETWORKING SYSTEMS IN I-IOT <s> Many technical communities are vigorously pursuing research topics that contribute to the Internet of Things (IoT). Nowadays, as sensing, actuation, communication, and control become even more sophisticated and ubiquitous, there is a significant overlap in these communities, sometimes from slightly different perspectives. More cooperation between communities is encouraged. To provide a basis for discussing open research problems in IoT, a vision for how IoT could change the world in the distant future is first presented. Then, eight key research topics are enumerated and research problems within these topics are discussed. <s> BIB001 </s> A Survey on Industrial Internet of Things: A Cyber-Physical Systems Perspective <s> IV. NETWORKING SYSTEMS IN I-IOT <s> The 3GPP has raised the need to revisit the design of next generations of cellular networks in order to make them capable and efficient to provide M2M services. One of the key challenges that has been identified is the need to enhance the operation of the random access channel of LTE and LTE-A. The current mechanism to request access to the system is known to suffer from congestion and overloading in the presence of a huge number of devices. For this reason, different research groups around the globe are working towards the design of more efficient ways of managing the access to these networks in such circumstances. This paper aims to provide a survey of the alternatives that have been proposed over the last years to improve the operation of the random access channel of LTE and LTE-A. A comprehensive discussion of the different alternatives is provided, identifying strengths and weaknesses of each one of them, while drawing future trends to steer the efforts over the same shooting line. In addition, while existing literature has been focused on the performance in terms of delay, the energy efficiency of the access mechanism of LTE will play a key role in the deployment of M2M networks. For this reason, a comprehensive performance evaluation of the energy efficiency of the random access mechanism of LTE is provided in this paper. The aim of this computer-based simulation study is to set a baseline performance upon which new and more energy-efficient mechanisms can be designed in the near future. <s> BIB002 </s> A Survey on Industrial Internet of Things: A Cyber-Physical Systems Perspective <s> IV. NETWORKING SYSTEMS IN I-IOT <s> Design and operation of a manufacturing enterprise involve numerous types of decision-making at various levels and domains. A complex system has a large number of design variables and decision-making requires real-time data collected from machines, processes, and business environments. Enterprise systems (ESs) are used to support data acquisition, communication, and all decision-making activities. Therefore, information technology (IT) infrastructure for data acquisition and sharing affects the performance of an ES greatly. Our objective is to investigate the impact of emerging Internet of Things (IoT) on ESs in modern manufacturing. To achieve this objective, the evolution of manufacturing system paradigms is discussed to identify the requirements of decision support systems in dynamic and distributed environments; recent advances in IT are overviewed and associated with next-generation manufacturing paradigms; and the relation of IT infrastructure and ESs is explored to identify the technological gaps in adopting IoT as an IT infrastructure of ESs. The future research directions in this area are discussed. <s> BIB003 </s> A Survey on Industrial Internet of Things: A Cyber-Physical Systems Perspective <s> IV. NETWORKING SYSTEMS IN I-IOT <s> By taking a physical architecture-oriented approach, we can create more effective Internet of Things systems on public cloud-based platforms. <s> BIB004 </s> A Survey on Industrial Internet of Things: A Cyber-Physical Systems Perspective <s> IV. NETWORKING SYSTEMS IN I-IOT <s> The smart grid, as one of typical applications supported by Internet of Things, denoted as a re-engineering and a modernization of the traditional power grid, aims to provide reliable, secure, and efficient energy transmission and distribution to consumers. How to effectively integrate distributed (renewable) energy resources and storage devices to satisfy the energy service requirements of users, while minimizing the power generation and transmission cost, remains a highly pressing challenge in the smart grid. To address this challenge and assess the effectiveness of integrating distributed energy resources and storage devices, in this paper, we develop a theoretical framework to model and analyze three types of power grid systems: 1) the power grid with only bulk energy generators; 2) the power grid with distributed energy resources; and 3) the power grid with both distributed energy resources and storage devices. Based on the metrics of the power cumulative cost and the service reliability to users, we formally model and analyze the impact of integrating distributed energy resources and storage devices in the power grid. We also use the concept of network calculus, which has been traditionally used for carrying out traffic engineering in computer networks, to derive the bounds of both power supply and user demand to achieve a high service reliability to users. Through an extensive performance evaluation, our evaluation results show that integrating distributed energy resources conjointly with energy storage devices can reduce generation costs, smooth the curve of bulk power generation over time, reduce bulk power generation and power distribution losses, and provide a sustainable service reliability to users in the power grid. <s> BIB005 </s> A Survey on Industrial Internet of Things: A Cyber-Physical Systems Perspective <s> IV. NETWORKING SYSTEMS IN I-IOT <s> Machine-to-machine (M2M) communications and applications are expected to be a significant part of the Internet of Things (IoT). However, conventional network gateways reported in the literature are unable to provide sustainable solutions to the challenges posted by the massive amounts of M2M communications requests, especially in the context of the IoT for smart cities. In this paper, we present an admission control model for M2M communications. The model differentiates all M2M requests into delay-sensitive and delay-tolerant first, and then aggregates all delay-tolerant requests by routing them into one low-priority queue, aiming to reduce the number of requests from various devices to the access point in the IoT for smart cities. Also, an admission control algorithm is devised on the basis of this model to prevent access collision and to improve the quality of service. Performance evaluations by network calculus, numerical experiments, and simulations show that the proposed model is feasible and effective. <s> BIB006 </s> A Survey on Industrial Internet of Things: A Cyber-Physical Systems Perspective <s> IV. NETWORKING SYSTEMS IN 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> BIB007
With the support of communication networks, machine devices can collect and exchange data amongst themselves to support numerous smart-world systems such as smart manufacturing, smart grid, and many others BIB005 , BIB004 , BIB001 . The communication associated with those machine devices is denoted as M2M communication, otherwise referred to as machine-type communication, supporting ubiquitous connectivity among machine devices without human intervention BIB006 - BIB007 . Along with the research and development of the 3rd Generation Partnership Project (3GPP) on LongTerm Evolution (LTE) and Long-Term Evolution Advanced (LTE-A) BIB002 , and the fifth generation wireless network (5G), M2M has been identified as a key technology for the future of communication. Recalling the I-IoT applications and characteristics in Section II-B, I-IoT is expected to interconnect a plethora of industrial devices and equipment from numerous previously isolated industrial systems. Such interconnections can improve the operability, productivity and resource efficiency of industrial applications. From the networking perspective, such an interconnection requires the design of high-capacity communication networks, which are capable of supporting industrial devices with strict quality of service (QoS) requirements. Moreover, the network shall improve its flexibility, scalability and interoperability to support connections in numerous isolated industrial systems so that flexible manufacturing can be supported BIB003 . We now investigate some of the representative network technologies mentioned, in the context of I-IoT. Specifically, we first introduce a three-dimensional framework, shown in Figure 7 , from which to investigate the existing research works related to networking systems in I-IoT. The framework consists of three orthogonal dimensions (i.e., physical systems, information types, and networking requirements). Based on the defined framework, we consider the existing research efforts on the state-of-the-art networking technologies (i.e., 5G, M2M, and SDN) for networking systems in I-IoT. In addition, we review the recent progress toward standardization for I-IoT from the perspective of networking. Figure 7 presents a framework to explore the problem space of networking systems in I-IoT. From the dimension of physical systems, we consider two types of system (i.e., PA, FA). In the information type dimension, we consider the different categories of information transmitted through the network, including control information, monitoring information, and others, which includes data sharing between subsystems. In the third dimension, we present the network performance requirements, including latency, reliability, and others (security, privacy, etc.), for the designated network system in I-IoT. For example, research efforts on leveraging 5G to improve the latency performance of real time monitoring of the production 78244 VOLUME 6, 2018 quality in manufacturing factories can be mapped into cube <Monitoring, Factory Automation, Latency> of Figure 7 .