A Comprehensive Review on Reconfigurable Intelligent Surface for 6G
Communications: Overview, Deployment, Control Mechanism, Application,
Challenges, and Opportunities
Abstract
The development of our neoteric scientific fields has reached such a
magnificent level that the benefits from innovation have extended to all
regions, including those most distant. Modern information and
communication network systems have greatly improved the overall
effectiveness and performance of the wireless networks. With the
emergence of cellular networks, the wireless communication network
system has evolved from the first generation to the sixth generation
(6G), which will provide an integrated framework for a variety of
utilities and applications. The goal of 6G network systems is to improve
channel capacity, low bit rate error, efficient signal transmission, and
low latency while providing reliable connectivity and seamless
communication. Various technologies are integrated with 6G network
systems to provide controlled, efficient, and reliable communication.
One emerging technology for 6G communication network systems is
reconfigurable intelligent surfaces (RIS), which is ideal for smooth and
controllable wireless signal transmission. RIS uses smart beamforming
methods with the assistance of an electronic circuit controller to
provide superior signal quality. This study presents a complete overview
of RIS, including its hardware architecture, key characteristics,
control mechanism, operating frequency, communication duplex mode, and
operating mode. The study also elaborates on the RIS operational
environment, advantages of implementing RIS, deployment, and different
types of communication by utilizing RIS. Finally, we conclude with a
discussion of challenges and future research directions to overcome
limitations to achieve the goal of RIS implementation and RIS-aided
communication for 6G communication systems.