Listen-While-Talking: Toward dApp-based Real-Time Spectrum Sharing in O-RAN

TL;DR

This paper demonstrates a dApp-based real-time spectrum sharing system in 5G O-RAN, enabling dynamic adaptation to incumbent users without dedicated Spectrum Access Systems, using open-source tools and real-world wireless environment testing.

Contribution

It introduces a novel dApp-based approach for real-time spectrum sensing and control in O-RAN, eliminating the need for dedicated Spectrum Access Systems in CBRS bands.

Findings

Effective detection of incumbent user transmissions.

Dynamic adaptation of gNB transmission strategies.

Potential for integrated spectrum sharing in next-gen networks.

Abstract

This demo paper presents a dApp-based real-time spectrum sharing scenario where a 5th generation (5G) base station implementing the NR stack adapts its transmission and reception strategies based on the incumbent priority users in the Citizen Broadband Radio Service (CBRS) band. The dApp is responsible for obtaining relevant measurements from the Next Generation Node Base (gNB), running the spectrum sensing inference, and configuring the gNB with a control action upon detecting the primary incumbent user transmissions. This approach is built on dApps, which extend the O-RAN framework to the real-time and user plane domains. Thus, it avoids the need of dedicated Spectrum Access Systems (SASs) in the CBRS band. The demonstration setup is based on the open-source 5G OpenAirInterface (OAI) framework, where we have implemented a dApp interfaced with a gNB and communicating with a Commercial Off-the-Shelf (COTS) User Equipment (UE) in an over-the-air wireless environment. When an incumbent user has active transmission, the dApp will detect and inform the primary user presence to the gNB. The dApps will also enforce a control policy that adapts the scheduling and transmission policy of the Radio Access Network (RAN). This demo provides valuable insights into the potential of using dApp-based spectrum sensing with O-RAN architecture in next generation cellular networks.