Add SIB 3,4 support, configurable SIB2 and refactor CU/DU SIB management
This MR makes neighbour and inter-frequency configuration drive how
SIB2/SIB3/SIB4 are built and sent from CU to DUs. It standardizes SIB
payloads as byte_array_t with typed SIB IDs across RRC, F1AP and MAC,
reducing ad‑hoc buffer handling. Neighbour parsing, validation and
lookup are tightened.
Changes
- Minor refactor to gNB neighbour parsing and storage (shared PLMN
extraction, safer allocation, etc).
- Represent SIB containers uniformly as byte_array_t plus nr_sib_type_t,
and adapt F1AP, MAC and RRC users to the new container API.
- Make SIB2 cell-reselection information fully config-driven with
explicit bounds checking and SIB2 ASN.1 building from that config.
- Generate SIB3 intra-frequency neighbours from the per-cell neighbour
list and propagate them from CU to DU over F1, with MAC
decoding/attaching them to SystemInformation.
- Generate SIB4 inter-frequency neighbours from a new frequency_list
plus neighbour SIB3/SIB4 offsets, and propagate them from CU to DU
over F1, with MAC decoding/attaching them.
- Add basic ASN.1 round-trip tests for SIB2/SIB3/SIB4 and SIB4 range
checks, and update RRC docs to describe the neighbour/inter-frequency
configuration model.
Testing:
1. in gNB conf file:
cu_sibs = (2, 3, 4);
2. Update neighbour config file with SIB3/SIB4 conf:
(see documentation)
3. run gNB and UE as usual
---
Logs & configs: see MR on Gitlab
Robert Schmidt
dc550ebaf6