Robert Schmidt afcd77108d Merge remote-tracking branch 'karimboutiba/xran_fdd' into integration_2026_w28
xran: fixes for FDD operation (#270)

Two fixes in the xran fronthaul found while bringing up an FDD cell
(Band n1, 10 MHz).  Verified on a Band n1 FDD 10 MHz cell using Keysight
RUsim/UEsim, End-to-end UE attach and traffic work.

- Derive TTI from the configured numerology instead of a hardcoded 20
  slots per frame: xran_fh_tx_send_slot() assumed 30 kHz SCS. Compute
  slots_per_frame as 10 << mu from the fronthaul config (mu_number[0]
  for K release, frame_conf.nNumerology for F release), so the TTI is
  correct for any numerology. With the original code, PRACH was not
  working properly.
- Fix DL transmission in FDD mode: the TDD DL/guard slot check skipped
  every DL slot in FDD, where no TDD pattern exists and all slots carry
  DL. The check is now only applied when the frame duplex type is not
  FDD. Without this, no DL traffic was sent.

Reviewed-by: Teodora Vladić <teodora.vladic@openairinterface.org>
Reviewed-by: Robert Schmidt <robert.schmidt@openairinterface.org>
2026-07-09 17:10:29 +02:00
2026-07-01 11:37:43 +02:00
2026-06-30 11:34:09 +02:00
2026-07-02 10:18:42 +02:00
2023-08-23 17:15:48 +02:00
2024-10-11 09:12:49 +02:00
2024-03-08 15:53:42 +01:00
2026-04-22 22:34:02 +02:00
2022-10-18 15:24:48 +02:00
2026-06-18 16:38:51 +02:00

Duranta OAI

License Supported OS Ubuntu 22 Supported OS Ubuntu 24 Supported OS Ubuntu 26 Supported OS RHEL9 Supported OS Fedora 44

Docker Pulls Docker Pulls Docker Pulls Docker Pulls Docker Pulls

Duranta - OpenAirInterface

Duranta OpenAirInterface RAN delivers and maintains an open-source cellular wireless software stack for 4G, 5G and future networking technologies. It supports simulation, prototyping, and end-to-end deployments on Commercial-Off-The-Shelf (COTS) hardware. Built for research and experimentation, it provides standard-compliant interfaces and is released under the Collaborative Standards Software License (CSSL).

License

The source code is distributed under CSSL v1.0. Some files, such as for orchestration, are distributed under MIT license. Documentation is distributed under Creative Commons Attribution 4.0 International license.

All the files without an explicit copyright header have an implicit "Copyright of OpenAirInterface Authors".

Please see NOTICE for other licenses which are used in the software.

In the past OAI source code has been re-licensed sometimes, here is the history:

  1. CSSL v1.0 starting tag 2026.w14
  2. OAI Public License v1.1 starting tag v1.0 till af4b0d53
  3. OAI Public License v1.0: starting tag v.04 till v1.0
  4. GPL 3: starting tag v.0 till v.04 (only initial implementation of 4G)

Where to Start

Not all information is available in a central place, and information for specific sub-systems might be available in the corresponding sub-directories. To find all READMEs, this command might be handy:

find . -iname "readme*"

RAN repository structure

The OpenAirInterface (OAI) software is composed of the following parts:

openairinterface5g
├── charts
├── ci-scripts        : Meta-scripts used by the OSA CI process. Contains also configuration files used day-to-day by CI.
├── CMakeLists.txt    : Top-level CMakeLists.txt for building
├── cmake_targets     : Build utilities to compile (simulation, emulation and real-time platforms), and generated build files.
├── common            : Some common OAI utilities, some other tools can be found at openair2/UTILS.
├── doc               : Documentation
├── docker            : Dockerfiles to build for Ubuntu and RHEL
├── executables       : Top-level executable source files (gNB, eNB, ...)
├── maketags          : Script to generate emacs tags.
├── nfapi             : (n)FAPI code for MAC-PHY interface
├── openair1          : Layer 1 (3GPP LTE Rel-10/12 PHY, NR Rel-15 PHY)
├── openair2          : Layer 2 (3GPP LTE Rel-10 MAC/RLC/PDCP/RRC/X2AP, LTE Rel-14 M2AP, NR Rel-15+ MAC/RLC/PDCP/SDAP/RRC/X2AP/F1AP/E1AP), E2AP
├── openair3          : Layer 3 (3GPP LTE Rel-10 S1AP/GTP, NR Rel-15 NGAP/GTP)
├── openshift         : OpenShift helm charts for some deployment options of OAI
├── radio             : Drivers for various radios such as USRP, AW2S, RFsim, 7.2 FHI, ...
├── targets           : Some configuration files; only historical relevance, and might be deleted in the future
└── tools             : Tools for use by the developers/ci machines: code analysis and formatting

How to get support from the Community

You can ask your question on the mailing lists.

Your email should contain below information:

  • A clear subject in your email.
  • For all the queries there should be [Query] in the subject of the email and for problems there should be [Problem].
  • In case of a problem, add a small description.
  • Do not share any photos unless you want to share a diagram.
  • OAI gNB/DU/CU/CU-CP/CU-UP configuration file in .conf format only.
  • Logs of OAI gNB/DU/CU/CU-CP/CU-UP in .log or .txt format only.
  • In case your question is related to performance, include a small description of the machine (Operating System, Kernel version, CPU, RAM and networking card) and diagram of your testing environment.
  • Known/open issues are present on Github, so keep checking.

Always remember a structured email will help us understand your issues quickly.

Languages
C 91.5%
CMake 3.3%
C++ 2.2%
TeX 1%
Python 0.8%
Other 1%