- Process all PDU sessions in handover request instead of only the first one
- Add DevAssert for bounds checking on nb_of_pdusessions
- Fix logic error where multiple PDU sessions were ignored in handover scenarios
Previously, the RRC layer was incorrectly allocating stack memory for the ho_required_transfer field and passing it to NGAP, however it was not used. The IE is mandatory but contains only 1 optional IE, therefore is encoded in the NG message with empty content.
Changes:
- Remove unnecessary ho_required_transfer field from pdusession_resource_t definition, the IE is encoded anyway with empty content. If Direct Forwarding Path Availability is needed at any stage in the future it can be added to pdusession_resource_t and filled in RRC.
- Add clarifying comment about empty HandoverRequiredTransfer structure
NR UE: in nr_ue_scheduler.c set LCID_buffer_remain to 0 if RLC indicates not
more bytes in buffer
If the RLC indicates that there is no more data in the buffer, also the
scheduler's LCID_buffer_remain should be set to 0. Else the UE sends BSR
indicating it has data to be transmitted. The gNB would then unnecessarily
schedule UL for this UE, which would not be used, as there is no actual data
to be transmitted.
Extend t300 in multi_ue rfsim testcase
Extend t300 to 1000 to increase the time the gNB has to handle MSG3. Hopefully
this prevents the UEs from timing out after MSG3. Add UE id to timer timeout
LOGs so the UE behavior can be traced through the stack.
Code cleanup (SRS, config files and more)
- Remove deprecated elements from some configuration files (also closes#997)
- Improve SRS code with a better separation between common code and gNB/UE code
- Other minor compilation improvements
Implementing the option to have more than 1 RSRP in CSI report
In collaboration with NI/Emerson.
The standard allows up to 4 RSRP measurements in CSI report (1 full and the other
differential). In current OAI, we just configure 1 RSRP report for the strongest
SSB. This MR allows to configure at gNB more than 1 RSRP report (depending on
config file, number of SSBs and UE capabilities) and makes changes at the UE to
send this report.
replace bad DCI by specific message for each case and add checks for bad...
Replace bad DCI by specific message for each case and add checks for bad
pointers, or sanitize detected warnings. Then fix several issues in DCI
decoding. With this MR, LTE UE has less bad DCI, and each bad DCI has a
reason better diagnosis.
If the RLC indicates that there is no more data in the buffer, also the scheduler's
LCID_buffer_remain should be set to 0. Else the UE sends BSR indicating it has data
to be transmitted. The gNB would then unnecessarily schedule UL for this UE, which
would not be used, as there is no actual data to be transmitted.
Correctly handle unpacking of the first RSRP report and its resource ID before processing additional reports.
Use the initial RSRP value as the reference for differential RSRP calculations in subsequent reports.
N2 handover
This MR introduces full support for N2 handover, covering handover
decision, preparation, execution, and notification between source and
target NG-RAN nodes.
Key features:
1. Handover Decision & Preparation:
- Implement N2 handover decision based on UE measurement reports.
- Generate the Handover Preparation Information message, including
RRCReconfiguration.
- Send Handover Required message from the source NG-RAN to the AMF.
2. Handover Execution:
- Decode and handle the Handover Request on the target NG-RAN.
- Process the Handover Command on the source gNB, triggering
RRCReconfiguration.
- Initiate Handover Notify after successful completion.
3 NGAP & RRC Enhancements:
- Implement NGAP encoding/decoding functions for Handover Required,
Handover Request, Handover Command, Handover Failure, and Handover
Notify (3GPP TS 38.413).
- Adds NG-RAN Status Transfer support (UL/DL) for PDCP COUNT
preservation during mobility:
- support for NGAP Uplink and Downlink RAN Status Transfer messages
(TS 38.413 §9.2.3.13-14) to enable proper PDCP COUNT value
transfer during handover or recovery: NGAP encoding/decoding for
RAN Status Transfer, PDCP helpers to extract and apply COUNT (HFN
+ SN) per DRB. This aligns with TS 38.300 §9.2.3.2.1 and TS 23.502
§4.9.1.3.3, ensuring PDCP status preservation in AM.
4. Testing:
- Introduce a Telnet command to manually trigger N2 handover using UE
ID and neighbor PCI.
- Add configuration file for testing N2 handover with a target gNB.
Guido Casati