- 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.
According to the RRC specification, cellSpecificKoffset is:
Scheduling offset used for the timing relationships that are modified for NTN (see TS 38.213 [13]).
The unit of the field K_offset is number of slots for a given subcarrier spacing of 15 kHz.
If the field is absent UE assumes value 0
This parameter `cellSpecificKoffset_r17` can be set in the gNB conf file, in the section `servingCellConfigCommon`
Till this commit, the UE gets the position of SSB in frequency from
command line and does the syncronization by locating the SSB in time. It
does this by generating a PSS time signal during initialization with the
SSB offset given via command line. Then PSS detection is done by
correlation.
In this commit, the UE computes a list of GSCN in the current NR band
that falls within the current bandwidth for the set center frequency.
For each GSCN in the list, the UE starts a thread and performs the
following:
1. Generate PSS time signal with SSB offset for current GSCN.
2. Detect PSS, SSS and decode PBCH (this step remains the same).
After all threads finishes, the results are collected.
For now, only the first detected PBCH is used to proceed further. So
this PBCH is indicated to MAC and UE exits initial sync.
Future work: The cell search can be standalone feature where the UE
could scan for SSB in the entire NR band. This would require changing
radio's frequency on the fly as the UE's bandwidth would not cover an
entire NR band. The cell detection can futher be imporved by looking
for SIB1 for each decoded PBCH.
- 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.
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.
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.
After the last commit, it is not possible to bind on separate interfaces
for F1-C and F1-U. In other words, it is for instance not possible to
have the F1-C on one subnet on one physical interface, and F1-U on
another subnet on another physical interface. This commit introduces a
second option MACRLCs.[0].local_n_address_f1u to allow to bind F1-U on
an alternative address; if it is not specified, the interface of F1-C is
reused.
The above only works for the DU; no corresponding option exists for the
CU. For the CU, use separate CU-CP and CU-UP.
Use it in the CI.
The original UL max MCS of 9 was chosen for performance reasons. In the
meantime, machines became faster, and the ULSCH decoding faster. Improve
UL max MCS to be 28 by default to use the complete range of possible
MCS.
Doing only 5 LDPC iterations by default leads to a poor reception
performance, and correspondingly many retransmissions. Increase to 8 as
the new default to improve user experience.
For 7.2 FH, some RUs do phase compensation, whereas for others, the DU
does it. In fact, this can be "negotiated" using the M plane. Since we
don't have the M plane yet, add a configuration option to set where
phase compensation is performed.
RRC Version is a required IE. Hence, implement the encoder and decoder
for this message. At the DU and CU, read the RRC Version we use and fill
the corresponding field.
Co-authored-by: Robert Schmidt <robert.schmidt@openairinterface.org>
In NSA, we don't have SIB1. However, the DU system information requires
both MIB and SIB1, but is itself optional. So, in NSA, don't fill the DU
system information.
remove several unused files
remove mem_block_t that is never used in a different way than a simple heap buffer
move up IP address type and remove duplications of the same struct declaration
The macrlc_has_f1 (static) variable was introduced to signal when we use
F1 in the configuration. It is superfluous: the node_type already passes
this information in a unique manner; hence, remove.
Robert Schmidt