The growing demand for wireless capacity and coverage has driven research into new radio architectures and higher frequency bands. The recently standardized Wireless Access Backhaul (WAB) architecture represents a key evolution, enabling cost-effective network densification through wireless relaying. This paper presents the first experimental realization of a multi-band WAB testbed, combining an FR2 backhaul and an FR1 access link using open-source software and commercial off-the-shelf components. The proposed framework validates the feasibility of end-to-end WAB operation and demonstrates its ability to extend FR2 coverage while maintaining compatibility with legacy FR1 user equipment. Experimental campaigns conducted in vehicular and outdoor-to-indoor scenarios confirm that WAB effectively mitigates the limitations of FR2 links, particularly in uplink and Non-Line-of-Sight conditions. These results highlight WAB as a practical and scalable approach for next-generation wireless networks.

翻译：无线容量与覆盖需求的日益增长推动了新型无线架构及更高频段的研究。近期标准化的无线接入回传（WAB）架构代表了一项关键演进，通过无线中继实现了经济高效的网络致密化。本文首次提出了多频段WAB测试平台的实验实现，该平台结合了基于开源软件与商用现成组件的FR2回传链路和FR1接入链路。所提出的框架验证了端到端WAB操作的可行性，并展示了其在保持与现有FR1用户设备兼容性的同时扩展FR2覆盖范围的能力。在车载及室外到室内场景下开展的实验验证表明，WAB能有效缓解FR2链路的局限性，尤其在上行链路与非视距传输条件下。这些结果凸显了WAB作为下一代无线网络的一种实用且可扩展的解决方案。