OpenAirInterface
Open-source 4G and 5G RAN, UE and core network code from the OpenAirInterface Software Alliance, now under the CSSL licence and moving to GitHub as the LF Networking Duranta project.
| Organisation | OpenAirInterface Software Alliance (OSA), a non-profit founded by EURECOM in 2014, based at EURECOM in Biot, France |
|---|---|
| Website | openairinterface.org/ |
| Licensing | RAN, CN5G and FlexRIC under the Collaborative Standards Software License v1.0 (CSSL), the RAN from tag 2026.w14 (earlier code under OAI Public License v1.1); EPC MME and HSS under BSD-3-Clause; orchestration files MIT; docs CC-BY-4.0 |
| Pricing | Software is free to download; patent use outside research needs FRAND licences from the patent holders; alliance membership (Strategic, Associate, Non-profit) has no public price list |
| Updated | 15 Nov 2026 |
Products and offerings #
| Name | Kind | Positioning |
|---|---|---|
| openairinterface5g (OAI RAN) | software | NR gNB with CU-CP, CU-UP, DU and RU splits, LTE eNB, and O-RAN 7.2 fronthaul as O-DU |
| OAI nrUE and lteUE | software | Software 5G NR and LTE UEs in the same repository, for use with an SDR or the RF simulator |
| OAI CN5G | software | 3GPP 5G core network functions (AMF, SMF, UPF and others) in C++, deployed with Docker Compose or Helm |
| FlexRIC | framework | O-RAN near-real-time RAN Intelligent Controller and E2 agent library |
| RF simulator | software | Virtual radio that links gNB and UE over sockets so the stack runs without RF hardware |
Who they are
This hub is for researchers and engineers who need a full 3GPP stack they can read and modify: gNB, UE and 5G core. OpenAirInterface (OAI) began as research code at EURECOM. According to the OSA’s about page, EURECOM founded the OpenAirInterface Software Alliance in 2014 as a non-profit, and a board of Strategic Members governs it. The alliance sits at EURECOM in Biot, near Sophia Antipolis.
Two things changed in 2026. The RAN code moved to a new licence, the CSSL. Then it moved to GitHub as Duranta, an LF Networking incubation project created with the OSA. The v3.0.0 tag, dated 9 October 2026, is described in its tag message as the first Duranta RAN and UE release. The new home is github.com/duranta-project/openairinterface5g. Older links point at gitlab.eurecom.fr.
Tooling and APIs
What you install. The RAN repository builds the NR gNB (whole, or split into CU-CP, CU-UP, DU and RU), the LTE eNB, and software UEs for both. The separate CN5G repositories hold the core network functions, shipped as Docker images with Compose files and Helm charts. FlexRIC adds an O-RAN near-real-time RIC. See O-RAN and the 5G NR hub.
Licensing at the time of writing. We read the LICENSE files. The RAN, CN5G and FlexRIC are under the Collaborative Standards Software License v1.0. The RAN README says CSSL applies from tag 2026.w14 and that older code was under OAI Public License v1.1. OAI’s licence model page describes the CSSL as a modified Apache License 2.0. The copyright grant is royalty-free. The patent licence is royalty-free only for study, testing and research. For other uses, section 3.2 commits you to be ready to negotiate fair, reasonable and non-discriminatory (FRAND) patent licences. Read the CSSL text yourself before shipping a product. The EPC MME and HSS are an exception under BSD-3-Clause.
OS support. Linux only. The supported-systems document lists Ubuntu 22.04, 24.04 and 26.04, Red Hat 9, Rocky 9, Fedora 43 and 44, and Debian 11 and 12. macOS is not listed, and the build expects Linux. On x86 the CPU must support AVX2. Arm64 servers such as Neoverse and Grace Hopper are listed.
Language. C for the RAN, C++ for most of the CN5G functions. There is no Python API. You configure the gNB with configuration files and command-line options. For debugging, the repository includes its own tracing framework (the T tracer, under common/utils/T).
Radios. The feature list names USRP and bladeRF, plus “others”. The source tree has drivers for USRP over UHD, bladeRF, LMS SDR, Iris, AW2S and O-RAN 7.2 fronthaul. That means a USRP B210, a USRP X310 or a bladeRF 2.0 micro for split 8 work, or a commercial O-RU for split 7.2. For tests without RF there are the RF simulator, vrtsim and a ZeroMQ radio. There is no SoapySDR driver and no GNU Radio integration. Use GNU Radio separately to inspect captured IQ.
Pain points. The system requirements ask for two dedicated 10 Gbit/s SFP+ links for USRP N3xx, X3xx and X4xx, and for CPUs with boost clocks above 4 GHz for those radios. A real-time kernel is optional. The code moves fast. Pin a tag and read the changelog before you upgrade.
Migration notes
- GitLab to GitHub. Update your remotes, CI and issue links. Tags before v3.0.0 remain on the EURECOM GitLab.
- OAI Public License to CSSL. Code from different tags carries different licences. Record which tag you forked from.
- From srsRAN. Both use UHD for split 8 USRP radios, so the hardware carries over. Configuration, logging and core attachment differ. See the srsRAN hub.
- Clocking. Commercial UEs need an accurate carrier. Use a 10 MHz reference or GPSDO with a USRP. See carrier frequency offset.
- Simulator first. Bring up gNB, nrUE and CN5G over the RF simulator, then add RF.
Watch for
- Patent terms. The CSSL grants a free patent licence for research only. Commercial use brings FRAND negotiations with patent holders.
- Spectrum. Over-the-air LTE or NR transmission needs a licence or test permit from your national regulator. See spectrum, security and regulation.
- Dormant subprojects. Mosaic5G has had little activity since 2021. Check commit dates before building on an OAI side project.
- Release maturity. A feature in the list does not mean it works with every UE or radio. Test with the hardware you plan to use.