Route paging-triggered Service Request through NAS_INITIAL_UL_TRANSFER_REQ so RRC can buffer the PDU for RRCSetupComplete (dedicatedNAS-Message, TS 38.331) when no UL-DCCH SRB exists, start MAC RA from RRC_IDLE, or drop the ITTI PDU with LOG_W if SRB1/SRB2 is already established (NAS paging path is 5GMM-IDLE only). Changes: - Define ITTI NAS_INITIAL_UL_TRANSFER_REQ and NAS_INITIAL_UL_TRANSFER_REQ() (rrc_messages_def.h, rrc_messages_types.h). - Extend NR_UE_RRC_INST_t with pending_initial_nas for setup-complete transport (rrc_defs.h). - Refactor ULInformationTransfer+PDCP send into nr_rrc_ue_send_ul_information_transfer_nas(): on NAS_UPLINK_DATA_REQ, refuse PDCP when neither SRB1 nor SRB2 is established (free PDU). - On NAS_INITIAL_UL_TRANSFER_REQ: store NAS in pending_initial_nas when no SRB, in RRC_STATE_IDLE_NR set ra_trigger to RRC_CONNECTION_SETUP, call nr_rrc_ue_prepare_RRCSetupRequest(), and nr_rrc_send_msg_to_mac() with NR_MAC_RRC_START_RA, otherwise replace pending and send on SRB. - Use forwarded initial NAS messafe in rrc_ue_generate_RRCSetupComplete(): if pending_initial_nas is set, move it into the NAS payload and refresh security keys when integrity context exists, else generateRegistrationRequest(). - In nr_nas_msg.c, add send_nas_initial_ul_transfer_req() and use it for paging Service Request instead of send_nas_uplink_data_req() Refs: TS 24.501, TS 38.331 §5.3.3.4, TS 33.501 §6.8.1.2 Signed-off-by: Guido Casati <guido.casati@openairinterface.org>
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:
- CSSL v1.0 starting tag 2026.w14
- OAI Public License v1.1 starting tag v1.0 till
af4b0d53 - OAI Public License v1.0: starting tag v.04 till v1.0
- GPL 3: starting tag v.0 till v.04 (only initial implementation of 4G)
Where to Start
- General overview of documentation
- The implemented features
- System Requirements for Using OAI Stack
- How to build
- How to run the modems
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
.confformat only. - Logs of OAI gNB/DU/CU/CU-CP/CU-UP in
.logor.txtformat 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.
