5G-LENA v5.0 is available

[Gabriel Ferreira]

Hi all,

We are happy to announce the v5.0 release of 5G-LENA. This release is compatible with ns-3.48.

Important: bug fix in the 3GPP spectrum model for FDD users

This release ships with an important heads-up for FDD users. We tracked down a bug in the 3GPP spectrum model that, under NLOS conditions, could make some UEs to receive up to 30 dB less power than they should. After applying the fix we measured up to a 1.4x reduction in the number of corrupted uplink transport blocks. We ran simulations to evaluate the impact, and on downlink focused workloads there is no significant impact. TDD users are not affected.

The fix lives upstream in ns-3. FDD users should apply the patch from merge request ns-3 MR2929. If you run FDD simulations, we strongly recommend applying it and re-checking any previously reported results.

While you are patching ns-3, we also encourage everyone to apply ns-3 MR2883, which delivers much faster 3GPP channel computations.

Highlights of this release

This release includes several new features, such as:

A major overhaul of the handover, RRC and radio-link-failure (RLF) machinery: inter-frequency and inter-numerology handovers, a same-cell primary-BWP switch mechanism, Cell Individual Offset (CIO) handover biasing (including negative offsets), msg3 HARQ retransmissions, RRC real-mode fixes, and FDD support in the RLF/RRC procedures, with much wider test coverage (X2 handover, inter-frequency handover, BWP switch, RLF over RRC ideal/real in both TDD and FDD).

Corrections to the UE measurement chain: RSRP is now averaged in the linear domain (fixing reports stuck at range 0 in multi-cell scenarios with data traffic), the RSRP reporting range mapping was updated to 5G-NR, RSRQ is now interference-aware, and the beam-scan and SRS channel-estimation models of the beamforming algorithms were fixed.

The fronthaul control model now supports selecting the functional split (FS 6, 7.1, 7.2 and 7.3), with per-split fronthaul throughput computations.

The NR module now builds on Windows: internal symbols are hidden and the public API is exported through the new NR_EXPORT macro.

A new cttc-nr-demo-sionna-rt example running an end-to-end NR deployment with the Sionna RT channel model, and a gsoc-leo-demo-example NTN example (GSoC 2025) integrating LEO satellite mobility with the 3GPP NTN channel and propagation models.

Unified RNG stream assignment behind NrHelper::AssignStreams() for reproducible simulations.

The documentation was heavily extended with new per-layer design chapters (PHY, MAC, RLC, PDCP, SDAP, RRC, NAS, EPC and the S1/S5/S11/X2 interfaces), sequence diagrams and state machines generated from committed sources, and traffic-pattern figures generated from simulation runs.

This release also includes important fixes, such as:

Fixed the code-block segmentation count in NrAmc::CalculateTbSize (TS 38.212 Section 5.2.2), which had been over-estimating the usable transport block size.

Fixed a UE RSRP measurement overflow and dB-domain averaging corruption that produced out-of-range RSRP values and permanently stalled A3-triggered handovers.

Fixed RLC-UM reassembly delivering corrupt SDUs after t-Reordering expiry, the RLC-UM PDCP discard being a no-op, and invalid framing-info transitions.

Fixed non-deterministic behavior from unstable sorts and standard shuffles, and the outdoor UE speed being stuck at the indoor value in the hexagonal grid scenario helper.

You can find the full list of changes in the release notes, and an at-a-glance view of everything supported in the features and roadmap pages.

As always, remember to follow the instructions in the README.md file, i.e., to check out the correct release branch of both ns-3 and the NR module.

We would like to thank all 5G-LENA users who contribute continuously to the 5G-LENA community by opening issues, proposing solutions, and answering on the 5G-LENA users list.

Thank you for your support!

To cite this NR 5.0 5G-LENA release, please use the reference on GitLab (in addition to the reference papers listed in https://5g-lena.cttc.es/papers/).

The 5G-LENA team