- neighbour_config.conf file includes neighbour and measurement related parameters
Neighbour List:
- nr_cellid: the identity of existing cell who has neighbour
- neighbour_cell_configuration(list): includes the identity parameters
of the neighbour cell such:
- gNBID (incase of N2 Handover / to be identified from AMF)
- nr_cell_id (target gNB needs to consider)
- physical_cellId (needed for measurement reporting)
- absoluteFrequencySSB (needed for measurement reporting)
- subcarrierSpacing (needed for measurement reporting)
- plmn / tracking area code (incase of N2 Handover / needed for AMF
to identify / allow HO)
NR Measurement Configuration
- Periodical
- enable (default is 0, 1 enables the reporting)
- includeBeamMeasurements, maxNrOfRS_IndexesToReport (configurable
reporting parameters)
- A2
- enable (default is 0, 1 enables the reporting)
- threshold , timeToTrigger (configurable reporting parameters)
- A3
- cell_id (the nr_cellid of neighbour cell. So this A3 parameters
will be used for the neighbour
- [-1] means default. so it can be applied to any neighbour if
there is no specific config
- Neighbour specific A3 Threshold can be used or default can be
selected depending to the neighbour planning
- The neighbour-config.conf specifies, apply default A3 for
neighbours 3 and 4 | apply specific one for neighbour 2
- offset, hysteresis, timeToTrigger (configurable reporting parameters)
the neighbour_config.conf can be included in the gNB.conf file. Example
is given: gnb.sa.band78.106prb.rfsim.neighbour.conf
A sequence array container is used for neighbour cell configuration. RRC
structure has this container. A Measurement configuration structure is
defined. This structure has Periodical / A2 Event structures and also a
sequence container for A3 Event List.
These structures are filled during the initialization. While F1 Setup
Response is coming from DU to CU, the intra frequency / inter frequency
neighbour decision is given for the existing cell. Also new neighbours
could be added here if needed.
The starting point was the function do_NR_DLInformationTransfer() which
may deal with more than 256 bytes.
Then why not cleanup all the functions in the same file.
(And do a bit of formattting fixing while we're here.)
Then cleanup the callers of those functions.
Then, because of do_SIB23_NR() let's also cleanup in some
structures.
Not all the codebase was cleaned up, there surely remain some uint8_t
(and char/short/uint16_t) which are wrong.
- addition of control of deltaMCS if enabled in configuration file.
- introduce separate parameter to disable 256QAM in UL
- put min_grant_prb configuration back in pf_ul() as default prb size.
uper_encode_to_buffer() of asn1c returns the number of BITS that have
been encoded; if we use this, we need to calculate the resulting number
of bytes (rounding up) to get the right buffer size.
Note that do_NR_ULInformationTransfer() uses
uper_encode_to_new_buffer() which returns the number of BYTES, hence, in
this similar function, we should not modify the return value.
In the case of PDU sessions in the NG UE context setup request, we first
have to set up security. Hence, in this commit, implement the "delayed"
set up of theses PDU sessions, and acknowledge the setup request after
reconfiguration, as requested by O-RAN.WG5.C.1-v11.
Trigger UE ctxt setup response for the case of "registration request"
(no PDU sessions in UE Context setup response), as mandated by
O-RAN.WG5.C.1-v11.
As of this commit, since we now send the UE security command as a DL NAS
message, there is no F1 UE Context setup request. Hence, instead of
sending a UE context modif request, send the UE context setup request
after the E1 bearer setup response (which logically also makes more
sense, as the E1 setup procedure comes before the F1 setup procedure).
This reverts commit 0f100a6e94, which
introduced a hack to possibly wait with a PDU session setup at the RRC
in case a RRC UE capability transaction (requesting UE capabilities from
a UE) was ongoing. This happened, as we delayed the UE capabilities to
after the first RRC reconfiguration; in that case, certain UEs were
requesting the next PDU session, and if RRC did not delay the new PDU
session (as requested from the core), this procedure might occur while
UE capability enquiry was ongoing, leading to failures in these
transactions.
The default RRC reconfiguration was previously sent after the security
mode command as a "first" RRC reconfiguration. However, it is simply not
needed, as it will be triggered through a subsequent reconfiguration
that also sets up DRBs.
Move the Measurement Config to the "other/dedicated" RRC
reconfiguration.
This reconfiguration would have forwarded a NAS PDU (typically a
registration accept). This is now done by a dedicated forwarding of NAS.
This reverts commit 4a7d7975ce.
Trigger the UE capability right after security mode complete, as
specified in O-RAN WG5.C.1-v11. Also, there is no "need" for the
"default" RRC Reconfiguration (it will come once PDU sessions are
requested), so remove this as well.
Previously, the CU sent the Security Mode Command as part of a UE
context setup request. This was done "because it was possible", not
because there was an inherent need to do this. However the LiteOn DU
does not like this, as it expects to also have a DRB in the UE context
setup request procedure, which is not always the case.
Hence, send the Security Mode Command in a normal DL RRC msg transfer
over F1. As of this commit, there is not UE context Setup Request (so it
might not work with all DUs), but the OAI DU is cool and does not care,
so RFsim still works.
This also aligns the CU's behavior with O-RAN.WG5.C.1-v11.
Finally, as of this commit, we do not trigger a UE context setup
request, so we cannot handle PDU sessions inside the initial UE context
setup request at the same time as the security mode command (which was
done previously before reaching this point). This will be fixed in a
later commit.
In the DU, read slice information from the DU config file. Handle
multiple slices within the F1 Setup Request structure representation,
and forward it via F1 to CU. The DU slice information is stored in the
setup request structure.
MeasTimingConfig may not come with F1 Setup Request: some DUs send it
with the DU configuration update. Handle this gracefully by checking for
MTC before using it.
Use the correct MIB data structure, MIB_t. This is required by 38.473,
and the LiteOn DU sends only that. So our CU needs to handle it, so
align the OAI DU as well.
- according to 5.3.7.4 of TS 38.331: 1> re-establish RLC for SRB1;
- gNB:
1) re-establish RLC for SRB1 in nr_rlc_update_id
2) re-establish RLC for remaining RBs concurrently with RRCReconfiguration
issue: gNB) in nr_rlc_update_id the gNB is re-establishing RLC for all
RBs at the same time when receiving RRCReestablishmentRequest
from UE
UE) according to the specs, the UE is re-establishing RLC for
SRB1 with RRCReestablishmentRequest the other RBs are
re-established during RRCReconfiguration (in our case in
nr_rrc_ue_process_RadioBearerConfig) when receiving
reestablishRLC IE in rlc_BearerToAddModList
RLC TX) this leads to RLC counters mismatch after re-establishment:
control PDUs discarded until max nb of retx is reached
and then UL failure occurs
- remove PDCP reestablishment for DRBs from RRCReestablishment message generation
- do PDCP reestablishment and CUUP notification calls after reception or RRCReestablishmentComplete
- this is necessary to make it consistent with the RRCReconfiguration message that contains
RadioBearerConfig with the list of bearers to add/release
which is followed by PDCP re-establishment at UE
- SRB1 shall be re-established at the time of RRCReestablishmentRequest
according to 5.3.7.4 of 3GPP TS 38.331
- SRB2 shall be re-established when creating srb-ToAddModList
according to 5.3.5.6.3 of 3GPP TS 38.331
batuhan duyuler