The advancement of Connected and Autonomous Systems (CAS) necessitates trust in decision-making, data sharing, and decentralized control, given their reliability, safety, and privacy requirements. Distributed consensus ensures all honest participants agree on a unified decision, maintaining system consistency and trust in operations. With the rise of 5G, IoT, and edge computing, more systems are wirelessly connected. However, most consensus algorithms are designed for wired networks, assuming stable TCP/IP communication. Wireless dynamics introduce challenges affecting consensus performance and security. This tutorial explores consensus in CAS, its applications, and how it builds a trustworthy environment. We cover consensus fundamentals, real-world use cases, and practical implementations in CAS. Additionally, we discuss methods to enhance trust through consensus and outline open research challenges, particularly in wireless network environments, where consensus remains a critical yet complex issue.
This in-depth tutorial explores consensus in CAS, its practical applications, and how it can be leveraged to establish a trustworthy environment. We begin by providing an overview of consensus mechanisms and CAS fundamentals, followed by an analysis of real-world use cases. Finally, we discuss methods for building a secure and decentralized CAS through consensus and highlight open research challenges in this evolving field. In particular, the tutorial will answer the following questions:
Why do we need consensus in CAS?
What is the role of consensus in CAS system?
What are the use cases of consensus in CAS?
What kind of consensus is currently widely used in CAS?
What are the differences between them and when should we choose which?
What is the trust requirement in CAS?
Why can consensus address these requirements, and how should we build the trust in CAS with consensus and other technologies supported by consensus?
How should we optimise current consensus protocols to be utilised in the typical wireless CAS scenario, and how much resource is needed?
Lei Zhang
University of Glasgow
Lei Zhang (Senior Member, IEEE) is a Professor of Trustworthy Systems at the University of Glasgow. He has academia and industry combined research experience on wireless communications and networks, and distributed and trustworthy systems for IoT, blockchain, and autonomous systems. His 20 patents are granted/filed in 30+ countries/regions. He published 3 books, and 150+ papers in peer-reviewed journals, conferences and edited books. Prof. Zhang is an associate editor of IEEE Transactions on Network Science and Engineering, IEEE IoT Journal, IEEE Wireless Communications Letters and Digital Communications and Networks, and a guest editor of IEEE JSAC, and IEEE Network Magazine. He received the IEEE Internet of Things Journal Best Paper Award 2022, IEEE ComSoc TAOS Technical Committee Best Paper Award 2019 and IEEE ICEICT’21 Best Paper Award. Dr. Zhang is the founding Chair of IEEE Special Interest Group on Wireless Blockchain Networks in IEEE Cognitive Networks Technical Committee (TCCN). He delivered tutorials in IEEE ICC’20, IEEE PIMRC’20, IEEE Globecom’21, Globecom’22, Globecom’24, IEEE VTC’21 Fall, IEEE ICBC’21 and EUSIPCO’21.
Website: https://www.gla.ac.uk/schools/engineering/staff/leizhang/
Google scholar: https://scholar.google.co.uk/citations?user=EP7beUwAAAAJ&hl=en