On the Concept of On-Demand RIS-Assisted 6G Networks: Applications and the Way Forward

There is power consumption in reconfigurable intelligent surfaces (RISs)-assisted systems caused by the multiplicative fading resulting from the two sub-channels induced by the RIS module. Therefore, the permanent use of the RIS module, especially when it is not needed, is resource mismanagement. Since infrastructure and operating costs in communications networks can be assessed by comparing them to previous generations, it is anticipated that the expenses associated with developing and operating the sixth generation (6G) of cellular networks will exceed those of the fifth generation. To lower these costs and efficiently manage RIS-related resources, multiple RIS-based strategies have been proposed. For example, using machine learning to control RIS elements. Nevertheless, these methods may also be costly to implement. In addition, the RIS module may not be required permanently in many circumstances. In this article, we introduce the concept of on-demand (OnD) RIS, which is a technology that only uses the RIS module when necessary. This offers resource management, cost-effectiveness, and energy efficiency advantages. In a case study, we demonstrate how the OnD RIS technology can be implemented. In addition, we discuss its impacts on the channel capacity and average received power. By introducing OnD RIS-assisted links into the 6G infrastructure, the equipment and operation costs can be reduced. Furthermore, when the demand for the OnD RIS ceases, the allocated resources can be reassigned to another use.