# Emerging Trends in Hybrid Wireless Communication and Data Management for the Industry 4.0
## 1 Introduction
In order to achieve this decentralized mode of operation, the communication network and the data management strategy must be built upon a flexible architecture capable of meeting the communication requirements of the industrial applications, with particular attention on time-critical automation [13]. Moreover, hybrid and hierarchical communication and data management strategies have to be employed. In this paper, we provide an overview of the network communications and data management emerging trends for the Industry 4.0 and the related architectural design. Particularly, we propose the implementation of hybrid communications management solutions and decentralized data distribution schemes supported by a hierarchical and multi-tier network architecture. The contribution of this paper is part of the work carried out in the H2020 AUTOWARE project [14]. The objective of AUTOWARE is to build an open consolidated ecosystem that lowers the barriers of small, medium, and micro-sized enterprises for cognitive automation application development and application of autonomous manufacturing processes. More specifically, the contributions of this paper are:  
* We focus on the emerging trends provided by the 3 GPP and 5 GPP by exposing selected industrial use cases and extracting the related critical requirements. Our global perspective is to understand the key communication and data management challenges and peculiarities for the effective realization of the fourth industrial revolution and suggest a holistic communication and data management architectural scheme. * We suggest a hierarchical multi-tier management scheme which combines local and decentralized management with centralized decisions to efficiently use the available communication resources and carry out the data management in the system. This scheme exploits the different capabilitiesof the available communication technologies (wired and wireless) to meet the wide range of requirements of the industrial applications. * We analyze the hybrid communication management and the decentralized data distribution. In this type of management, the distributed communication and data entities interact in order to coordinate their decisions and ensure the correct operation of the whole network. * We propose the use of RAN (Radio Access Network) slicing to efficiently manage the different communication and data management requirements of Industry 4.0 applications, and we present how the management of these RAN slices can be supported by the proposed hybrid management system. In Section 2, we outline the identified industrial use cases related to different application areas, such as process and factory automation, logistics warehousing and monitoring, etc. Then, we extract the relevant critical requirements in terms of end-to-end latency, communication service availability, typical message size, and the typical number of devices. In Section 3, we outline the major general challenges and particularities of the factories of the future, and we highlight the specific communication and data management challenges. In Section 4, we expose the recent architectural trends for 5G enabled communications and data management in Industrial Wireless Networks. In Section 5, we detail the communications and data management architectural scheme that we propose so as to provide hierarchical and multi-tier management for Industrial Wireless Networks. At first, we suggest a hierarchical multi-tier management scheme which combines local and decentralized management with centralized decisions to efficiently use the available communication resources and carry out the data management in the system. Then, we analyze the hybrid communication management and the decentralized data distribution. Finally, we propose in Section 6 the use of RAN slicing to achieve the flexibility required to meet the varying and stringent communication and data management requirements of the factories of the future and analyze how RAN slicing can be implemented considering the proposed hybrid management system.