WaveFlex: A Smart Surface for Private CBRS Wireless Cellular Networks

TL;DR

WaveFlex is a novel smart surface designed to enhance Private LTE/5G networks in the CBRS band, providing significant SNR and throughput improvements without modifying existing network infrastructure.

Contribution

It introduces the first smart surface that operates independently to improve Private LTE/5G performance in shared spectrum environments, handling frequency diversity and dynamic channel switching.

Findings

Achieved an 8.50 dB average SNR gain.

Realized a 4.36 Mbps throughput increase for a single small cell.

Demonstrated effective operation in a realistic indoor scenario.

Abstract

We present the design and implementation of WaveFlex, the first smart surface that enhances Private LTE/5G networks operating under the shared-license framework in the Citizens Broadband Radio Service frequency band. WaveFlex works in the presence of frequency diversity: multiple nearby base stations operating on different frequencies, as dictated by a Spectrum Access System coordinator. It also handles time dynamism: due to the dynamic sharing rules of the band, base stations occasionally switch channels, especially when priority users enter the network. Finally, WaveFlex operates independently of the network itself, not requiring access to nor modification of the base station or mobile users, yet it remain compliant with and effective on prevailing cellular protocols. We have designed and fabricated WaveFlex on a custom multi-layer PCB, software defined radio-based network monitor, and supporting control software and hardware. Our experimental evaluation benchmarks an operational Private LTE network running at full line rate. Results demonstrate an 8.50 dB average SNR gain, and an average throughput gain of 4.36 Mbps for a single small cell, and 3.19 Mbps for four small cells, in a realistic indoor office scenario.