Reconfigurable Intelligent Surfaces (RISs) constitute the key enabler for programmable electromagnetic propagation environments, and are lately being considered as a candidate physical-layer technology for the demanding connectivity, reliability, localization, and sustainability requirements of next generation wireless networks. In this paper, we first present the deployment scenarios for RIS-enabled smart wireless environments that have been recently designed within the ongoing European Union Horizon 2020 RISE-6G project, as well as a network architecture integrating RISs with existing standardized interfaces. We identify various RIS deployment strategies and sketch the core architectural requirements in terms of RIS control and signaling, depending on the RIS hardware architectures and respective capabilities. Furthermore, we introduce and discuss, with the aid of simulations and reflectarray measurements, two novel metrics that emerge in the context of RIS-empowered wireless systems: the RIS bandwidth and area of influence. Their extensive investigation corroborates the need for careful deployment and planning of the RIS technology in future networks.

翻译：可重构智能表面（RIS）是实现可编程电磁传播环境的关键技术，近来正被视为满足下一代无线网络对连接性、可靠性、定位及可持续性等严苛需求的候选物理层技术。本文首先介绍了欧盟地平线2020 RISE-6G项目中近期设计的RIS赋能智能无线环境部署场景，以及将RIS与现有标准化接口集成的网络架构。我们明确了多种RIS部署策略，并基于RIS硬件架构及其相应能力，勾勒出RIS控制与信令方面的核心架构需求。此外，通过仿真和反射阵列测量，我们引入并讨论了RIS赋能无线系统中涌现的两个新指标：RIS带宽与影响区域。对这两个指标的广泛研究证实，在未来网络中部署和规划RIS技术时需进行审慎的统筹。