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, the enhanced capabilities of RISs within PWEs, especially as we move toward more complex electromagnetic functions by increasing the number of reflecting elements, underscore the need for high-precision user localization, since inaccurate localization could lead to erroneous configuration of RISs, which would then compromise the effectiveness of PWEs. In this direction, this paper investigates the integration of RISs and optical anchors within 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 RISbased 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 the ambitious goals of the 6G standards and improve the quality of service in next generation wireless networks.

翻译：向第六代（6G）无线网络演进的过程中，可编程无线环境（PWE）与可重构智能表面（RIS）已成为实现近确定性无线通信的变革性要素。然而，随着反射单元数量的增加以实现更复杂的电磁功能，RIS在PWE中的增强能力凸显了对高精度用户定位的需求——定位误差将导致RIS配置错误，进而损害PWE的有效性。为此，本文研究了PWE中RIS与光学锚点的集成方案，强调超精确定位在解锁先进电磁功能中的关键作用。具体而言，我们深入分析了基于RIS及独立于RIS的多种定位技术，同时提出利用光学锚点增强PWE定位精度的概念。研究结果表明，精准定位是充分挖掘RIS潜力的必要条件，为未来应用开辟了道路。通过这项探索，我们推动了PWE技术向6G标准的宏伟目标迈进，并提升了下一代无线网络的服务质量。