Multi-Band Wireless Access-and-Backhaul (WAB) for 5G: Implementation and Experiments

2025-11-20

AI Summary

To address the limited coverage of 5G high-frequency bands (FR2), poor non-line-of-sight (NLoS) and uplink performance, and high backhaul deployment costs, this work presents the first end-to-end, multi-band wireless access-and-backhaul (WAB) integrated experimental platform. It jointly leverages FR2 for backhaul and FR1 for access, implemented using open-source software and commercial off-the-shelf hardware to enable dual-band coordination and wireless relaying. The platform breaks the FR2 coverage bottleneck by demonstrating robust transmission under challenging NLoS conditions—including vehicular mobility and indoor/outdoor penetration—significantly enhancing link reliability and coverage range. Crucially, it maintains full backward compatibility with legacy FR1 user equipment, ensuring operational flexibility and scalability for large-scale deployment. This low-cost, reproducible testbed provides empirical validation for key 6G enablers, including reconfigurable air interfaces and integrated access-and-backhaul (IAB).

Technology Category

• Application Domains: Mobility, Driving & Flight
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Application Category

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Abstract

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.

Problem

• Experimental validation of multi-band wireless access-backhaul integration for 5G networks
• Extending FR2 coverage while maintaining compatibility with legacy FR1 equipment
• Mitigating FR2 limitations in uplink and Non-Line-of-Sight conditions

Innovation

• Multi-band WAB testbed with FR2 backhaul
• Open-source software and COTS components
• Extends FR2 coverage with FR1 compatibility