5G srsRAN End-to-End Reference Architecture with USRP

Application Note Number and Authors

AN-599

Authors

Bharat Agarwal and Neel Pandeya

Executive Summary

This Application Note presents a comprehensive reference design for deploying 5G NR Standalone (SA) systems using a hybrid open-source software stack: the srsRAN radio access network components and the OpenAirInterface (OAI) Core Network. This setup runs on NI/Ettus USRP radios, including the B210, enabling practical, low-cost, end-to-end 5G experimentation.

This configuration supports full 5G SA mode and enables complete end-to-end evaluation of the entire protocol stack, from the physical layer up to the core network.

Core Network Deployment Options

The OAI Core Network can be deployed in two modes:

• Single-machine deployment: CN and gNB run on the same machine — ideal for compact or portable test setups.
• Multi-machine deployment: CN is hosted on a separate machine — ideal for performance scaling or distributed 5G architecture evaluation.

UE Configuration Options

This reference architecture supports the following UE configurations:

• A software-defined UE implemented using srsUE with a USRP B210.
• A modem-based UE, such as Quectel or Sierra Wireless modules.
• A COTS 5G handset (e.g., Google Pixel 9) for interoperability and benchmarking.

Overview of the OpenAirInterface (OAI) Software Stack

The OAI) software provides a fully open-source and standards-compliant implementation of the 3GPP 5G New Radio (NR) protocol stack. It is designed to run in real time on commodity x86 hardware and interoperate with USRP software-defined radios.

Initially developed by Eurecom, a leading research institute in France, the project is now actively maintained by the OpenAirInterface Software Alliance (OSA) — a non-profit organization that promotes open wireless innovation and collaborative research.

OAI enables complete 5G system prototyping and research with implementations of:

• The gNB (next-generation base station)
• The UE (user equipment)
• The 5G Core Network (5GCN)

The OAI 5G NR stack is designed to:

• Operate in real time with USRP radios
• Support interoperability with commercial 5G NR handsets (e.g., COTS devices)
• Enable academic, experimental, and pre-commercial deployments

The OAI software stack is organized into multiple Git repositories, allowing modularity and collaborative development:

• OAI 5G Radio Access Network (RAN) Project:

 gitlab.eurecom.fr/oai/openairinterface5g

• OAI 5G Core Network (OAI-CN):

 gitlab.eurecom.fr/oai/cn5g

OAI source code is freely available for non-commercial and academic research use. Licensing details and additional documentation are available on the OpenAirInterface website.