Empowering Programmable Wireless Environments With Optical Anchor-Based Positioning

The evolution toward sixth-generation (6G) wireless networks has introduced programmable wireless environments (PWEs) and reconfigurable intelligent surfaces (RISs) as transformative elements for achieving near-deterministic wireless communications. However, as RIS capabilities advance with the addition of more reflecting elements, the need for high-precision user localization becomes increasingly critical, since inaccurate localization could lead to erroneous RIS configuration. In this direction, this paper investigates the integration of RISs and optical anchors in PWEs, emphasizing the crucial role of ultra-precise localization in unlocking advanced electromagnetic functionalities. Specifically, we present an in-depth analysis of various localization techniques, both RIS-based and RIS-independent, while introducing the concept of empowering PWEs with optical anchors for enhanced localization precision. Our findings highlight that accurate localization is essential to fully exploit the capabilities of RISs, paving the way for future applications. Through this exploration, we contribute to the advancement of PWEs in line with 6G networks and the improvement of service quality in next-generation wireless networks.