Both reconfigurable intelligent surfaces (RISs) and ultra-dense (UD) small-cell (SC) base stations (BSs) are investigated for indoor mmWave wireless coverage enhancement. To explore which deployment strategy is more cost-effective, the costs of deploying both RISs and UD SCs are defined and calculated. Through jointly analyzing coverage probability and network cost in typical indoor environments, we conclude that the same network coverage can be achieved by multiple deployment strategies. To achieve certain level of coverage probability with the lowest network cost, a proper number of BSs are crucial for RIS-assisted networks.

中文翻译：

---

增强室内毫米波无线覆盖范围：小蜂窝密集化还是可重新配置的智能表面部署？


可重构智能表面 (RIS) 和超密集 (UD) 小蜂窝 (SC) 基站 (BS) 均用于增强室内毫米波无线覆盖范围。为了探索哪种部署策略更具成本效益，定义并计算了部署 RIS 和 UD SC 的成本。通过对典型室内环境下的覆盖概率和网络成本的联合分析，我们得出结论：多种部署策略可以实现相同的网络覆盖。为了以最低的网络成本实现一定的覆盖概率，适当数量的基站对于RIS辅助网络至关重要。