Exploring the use of mobile IRS in a vehicular context

Intelligent Reflecting Surfaces or IRSs are energy-efficient technologies used as “passive” relays to increase coverage. Often fixed, they enable connectivity to users in positions that are difficult for the base station to access, or that are blind. Most studies propose fixed IRS positioning, with the disadvantage of covering only a fixed zone. Therefore, in the vehicular environment, it would be interesting to see the feasibility of placing IRSs following traffic. We, therefore, propose to study the mobile placement of IRSs in a vehicular context first by using an optimizer and then by relying on heuristics. In the first part, we compare fixed and mobile IRS positioning. Then, for the heuristic part, we present different IRS election strategies, which we have compared. Performances are compared between fixed and mobile placement in the first part, and between one and two hops in the second part, all while analyzing the impact of different parameters on these results. We also evaluated the impact of a trajectory predictor and the dataset on these results. • When there are few available IRSs or a small coverage area, mobile placement is more effective than fixed placement. • The selection of IRSs in relation to the population to be covered is crucial. • In addition, incorporating prediction improves these performances.