Robert Schmidt
8ea95a0e52
The current contention-free random access forces a "Msg3" (which does not exist in CFRA) to be received by a UE. Sometimes, this "Msg3" is not received (for whatever reason), and the MAC declare that RA failed. This is problematic, as the spec says that RA is complete once Msg2 is received by the UE. To avoid this, inconditionally mark RA as complete as soon as we receive an indication of Msg3 (DTX or not). Note that after this change, we still send a UL grant in Msg2. This is because 38.321 §5.1.4 is not clear to me whether we should send UL grant (it does not explicitly exclude it), and it says > 3> if the Random Access Response includes a MAC subPDU with RAPID only: > [...] > 4> indicate the reception of an acknowledgement for SI request to > upper layers. which is NOT the case (but then I don't know/think we can have CFRA for SI request?). Since it also works with COTS UE, I leave Msg3 for the moment. The reason to not directly mark RA as complete when sending Msg2 is because of possible retransmissions in do-ra mode. In fact, in do-ra, there might already be data awaiting. In that case, the DLSCH scheduler schedules data _in the same slot as Msg2_, which the UE does not decode, leading to retransmissions.
OpenAirInterface License
It is distributed under OAI Public License V1.1.
The license information is distributed under LICENSE file in the same directory.
Please see NOTICE file for third party software that is included in the sources.
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 OAI Community
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- For all the queries there should be [Query] in the subject of the email and for problems there should be [Problem].
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- 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 GitLab, so keep checking.
Always remember a structured email will help us understand your issues quickly.