Robert Schmidt
4a7d7975ce
We used to trigger the UECapabilityEnquiry right after SecurityModeComplete, and before the RRCReconfiguration (which we call "default" reconfiguration). However, 38.401 tells us that we should send the RRCReconfiguration right after the SecurityModeComplete. In fact, even though we get the UE capabilities, we cannot use them during this reconfiguration, as we would first need to update the DU with a UE Context Modification Request, which we cannot, as we just sent the UE Context Setup Request, and the DU relies on first getting the RRCReconfiguration. Since we rely on a subsequent reconfiguration anyway, we can safely trigger the UECapabilityEnquiry after RRCReconfigurationComplete. (38.331 also says we can send UECapabilityEnquiry at any point.) To cater for the possibility that there might not be any reconfiguration coming afterwards, we check if a DRB has been set up. If not, we assume a reconfiguration will come, and do not trigger one only for the UE capabilities (this is what we do before this commit). If we already have DRBs set up, they might have been set up during the "default" RRC Reconfiguration, and another reconfiguration might not follow soon; in this case, we trigger the reconfiguration by sending the UE capabilities to the DU right away.
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
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 : 3GPP LTE Rel-10/12 PHY layer / 3GPP NR Rel-15 layer. A local Readme file provides more details.
├── openair2 : 3GPP LTE Rel-10 RLC/MAC/PDCP/RRC/X2AP + LTE Rel-14 M2AP implementation. Also 3GPP NR Rel-15 RLC/MAC/PDCP/RRC/X2AP.
├── openair3 : 3GPP LTE Rel10 for S1AP, NAS GTPV1-U for both ENB and UE.
├── openshift : OpenShift helm charts for some deployment options of OAI
├── radio : Drivers for various radios such as USRP, AW2S, RFsim, ...
└── targets : Some configuration files; only historical relevance, and might be deleted in the future