Analysis and Evaluation of a Wired/Wireless Hybrid Architecture for Distributed Control Systems With Mobility Requirements

Abstract

Wireless communications offer significant benefits over wired communications, which has increased their popularity in industrial applications. Nevertheless, the existing wireless standard technologies do not satisfy the requirements demanded by the most critical industrial applications and thus, wired communications cannot be directly replaced by wireless solutions. Moreover, the inclusion of movable nodes in the network brings new challenges, such as the handover mechanism. In this paper, a hybrid wired/wireless architecture designed for industrial control applications is proposed. To control the wired network, a timesensitive network (TSN) is used and to control the wireless network a medium access control (MAC) protocol is designed. In order to communicate both networks, a bridge that acts as a deterministic access point (AP) with real-time features is also proposed. One of the fundamental parts of the proposed architecture is that it can be used in applications with mobility requirements. Hence, a soft-handover algorithm is designed which guarantees uninterrupted communication during its execution without the need for a second radio interface and with reduced growth in network overhead. The proposed architecture is evaluated in order to assess its performance. This paper extends our previous work, including both a theoretical analysis to determine the delay bounds of the proposed architecture and a comparison between the performances of the proposed handover algorithm with other algorithms proposed in the literature. The evaluation has been carried out through OMNeT++ simulations. The results demonstrate the superiority of the proposed handover algorithm compared with other state-of-the-art solutions. INDEX TERMSHandover, IEEE 802.11, industrial communications, industrial wireless sensor and actuator networks, real-time communications, SHARP, TSN, wireless communications. ZALOA FERNÁNDEZ received the B.Sc. degree in telecommunications systems engineering and the M.Sc. degree in embedded systems from the University of Mondragon, Spain, in 2014 and 2016, respectively. She is currently pursuing the Ph.D. degree with the Communications Systems Group, IKERLAN Technological Research Centre, Mondragón, Spain, in collaboration with the Signal Theory and Communications Group, University of Mondragon, Spain. Her research interest includes reliable wireless time-critical communications for industrial automation applications. ÓSCAR SEIJO received the B.Sc. and M.Sc. degrees in telecommunications engineering from the University of Oviedo, Spain, in 2015 and 2017, respectively. He is currently pursuing the Ph.D. degree with the Communications Systems Group of IKERLAN Technological Research Centre, Mondragón, Spain, in collaboration with the Signal Theory and Communications (TSC) Group, University of Oviedo, Spain. His research interests include wireless high-performance PHY and MAC design for industrial applications, time synchronization over wireless systems, and digital signal processing. MIKEL MENDICUTE received the B.S...

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