The NR module is a pluggable module for ns-3 that can be used to simulate 5G New Radio (NR) cellular networks. The simulator is the natural evolution of LENA, the LTE/EPC Network Simulator, but its development started from the mmWave module because it was more advanced in terms of beamforming, TDD, 3GPP channel model, and operation at FR2. It incorporates fundamental PHY-MAC NR features aligned with 3GPP NR Release-15.

It is a module that can be plugged in ns-3-dev, starting from version 3.31, and supports the following features:

• Non-Standalone Architecture (NSA) architecture: 5G RAN and 4G EPC
• Compatiblility with ns-3 spatial channel and antenna array models (based on 3GPP 38.901 and able to simulate 0.5-100 GHz frequency ranges)
• Time Division Duplexing (TDD) and Frequency Division Duplexing (FDD) modes, with configurable TDD patterns
• Flexible and automatic configuration of the NR frame structure through multiple numerologies
• Time-Division Multiple Access (TDMA) and Orthogonal Frequency-Division Multiple Access (OFDMA)-based access with variable transmission time intervals and single beam capability
• Enhanced MAC layer, including flexible MAC schedulers that simultaneously consider time- and frequency-domain resources (resource blocks and OFDM symbols) both for TDMA and OFDMA-based access schemes with variable TTI
• UpLink (UL) grant-based access scheme with scheduling request and 3GPP-compliant buffer status reporting
• NR-compliant processing delays and control timings (N0, N1, N2; K0, K1, K2)
• Bandwidth Part (BWP) managers and the architecture to support operation through multiple BWPs and component carriers
• NR PHY layer abstraction, considering LDPC codes, MCS Tables 1 and 2 (up to 256-QAM), LDPC base graph selection and NR block segmentation
• Helpers to easily manage spectrum regions configuration, to allow Multi-Cell Configurations (easing the process of creating multiple cells with different configurations)
• Radio Environment Map (REM) helpers, capable of creating downlink and uplink (REM) maps
• Helpers to create topologies, e.g., hexagonal topology helper and grid topology helper
• Various helpers that generate traces at different layers of the protocol stack
• Interference management/coordination (including ICIC and notching), based on almost blank slots
• Uplink power control
• Sounding reference signals (SRS) modeling
• Realistic beamforming based on SRS-based channel estimates

We additionally offer two extensions of the NR module: NR-U an NR V2X extensions. NR-U is distributed as a separate module, while NR V2X is distributed as a branch of the NR module.

• NR-U extension aims to operate in unlicensed spectrum, through multiple channel access managers, including duty-cycling as well as Listen-Before-Talk (LBT)-based procedures.
• NR V2X extension is intended for vehicular communications, including support of NR frame structure, PSCCH and PSSCH multiplexing, resource allocation for NR V2X using mode 2 (autonomous resource selection), SCI (Sidelink Control Information) update, compliance with scenarios and channel models based on TR 38.885. Our initial focus is on: frequency range 1 with numerologies 0, 1, and 2, TDD system, out-of-coverage scenarios, mode 2 resource allocation, broadcast communications, omnidirectional transmissions/receptions for sidelink, sensing-based semi-persistent scheduling (for basic service messages), slot-based scheduling, PSCCH/PSSCH time multiplexing, and blind retransmissions.

Publications

Please refer to the following publications for further information about the capabilities, implementation model and validation details of the 5G-LENA Simulator:

• N. Patriciello, S. Lagen, B. Bojovic, L. Giupponi, An E2E Simulator for 5G NR Networks, Elsevier Simulation Modelling Practice and Theory (SIMPAT), vol. 96, 101933, Nov. 2019.
• N. Patriciello, S. Lagen, B. Bojovic, L. Giupponi, NR-U and IEEE 802.11 Technologies Coexistence in Unlicensed mmWave Spectrum: Models and Evaluation, in IEEE Access, vol. 8, pp. 71254-71271, 2020.
• S. Lagen, L. Giupponi, A. Hansson, X. Gelabert, Modulation Compression in Next Generation RAN: Air Interface and Fronthaul trade-offs , IEEE Communications Magazine, Vol. 59, No. 1, pp. 89-95, January 2021.
• Z. Ali, S. Lagen, L. Giupponi, R. Rouil, 3GPP NR V2X Mode 2: Overview, Models and System-level Evaluation, IEEE Access, vol. 9, pp. 89554-89579, June 2021.
• S. Lagen, X. Gelabert, L. Giupponi, A. Hansson, Fronthaul-Aware Scheduling Strategies for Next Generation RANs , in Proceedings of Global Communications Conference (GLOBECOM), 7-11 December 2021, Madrid (Spain).
• Z. Ali, S. Lagen, L. Giupponi, On the Impact of Numerology in NR V2X Mode 2 with Sensing and Random Resource Selection, IEEE Vehicular Networking Conference (VNC), Nov. 2021.
• S. Lagen, X. Gelabert, L. Giupponi, A. Hansson, Semi-Static Modulation Compression Optimization for Next Generation RANs , in Proceedings of IEEE International Conference on Communications, 14-23 June 2021, virtual event.
• B. Bojovic, S. Lagen, L. Giupponi, Realistic beamforming design using SRS-based channel estimate for ns-3 5G-LENA module, in Workshop on ns-3, June 2021.
• T. Zugno, M. Drago, S. Lagen, Z. Ali, M. Zorzi, Extending the ns-3 Spatial Channel Model for Vehicular Scenarios, in Workshop on ns-3, June 2021.
• K. Koutlia, B. Bojovic, S. Lagen, L. Giupponi, Novel Radio Environment Map for the ns-3 NR Simulator, in Workshop on ns-3, June 2021.
• T. Zugno, M. Polese, N. Patriciello, B. Bojovic, S. Lagen, M. Zorzi, Implementation of A Spatial Channel Model for ns-3, in Workshop on ns-3, June 2020.
• S. Lagen, K. Wanuga, H. Elkotby, S. Goyal, N. Patriciello, L. Giupponi, New Radio Physical Layer Abstraction for System-Level Simulations of 5G Networks, in Proceedings of IEEE International Conference on Communications (IEEE ICC), 7-11 June 2020.
• S. Lagen, N. Patriciello, L. Giupponi, Cellular and Wi-Fi in Unlicensed Spectrum: Competition leading to Convergence, in 6G Wireless Summit, 17-20 March 2020.
• N. Patriciello, S. Lagen, L. Giupponi, B. Bojovic, The impact of NR Scheduling Timings on End-to-End Delay for Uplink Traffic, in Proceedings of IEEE Global Communications Conference (IEEE GC), 9-14 December 2019, Waikoloa (HI, USA).
• N. Patriciello, S. Lagen, L. Giupponi, B. Bojovic, An Improved MAC Layer for the 5G NR ns-3 module, in Workshop on ns-3, 19-20 June 2019, Florence (Italy).
• N. Patriciello, S. Lagen, L. Giupponi, B. Bojovic, 5G New Radio Numerologies and their Impact on the End-To-End Latency, in Proceedings of IEEE International Workshop on Computer-Aided Modeling Analysis and Design of Communication Links and Networks (IEEE CAMAD), 17-19 September 2018, Barcelona (Spain).
• B. Bojovic, S. Lagen, L. Giupponi, Implementation and Evaluation of Frequency Division Multiplexing of Numerologies for 5G New Radio in ns-3, in Workshop on ns-3, 13-14 June 2018, Surathkal (India).

If you use the NR module in your research, please cite N. Patriciello, S. Lagen, B. Bojovic, L. Giupponi, An E2E Simulator for 5G NR Networks, Elsevier Simulation Modelling Practice and Theory (SIMPAT), vol. 96, 101933, Nov. 2019. Available here: http://arxiv.org/abs/1911.05534 .

If your work is based on the NR-U extension, please cite N. Patriciello, S. Lagen, B. Bojovic, L. Giupponi, NR-U and IEEE 802.11 Technologies Coexistence in Unlicensed mmWave Spectrum: Models and Evaluation, in IEEE Access, vol. 8, pp. 71254-71271, 2020.

If your work is based on the NR V2X extension, please cite Z. Ali, S. Lagen, L. Giupponi, R. Rouil, 3GPP NR V2X Mode 2: Overview, Models and System-level Evaluation, IEEE Access, vol. 9, pp. 89554-89579, June 2021.

Future work

The following features are intended to be added to the project in the future:

• Dual polarized antennas
• MIMO modeling, supporting two streams through dual-polarized antennas
• Rank adaptation algorithms for MIMO
• UL configured grant
• QoS schedulers
• Real modeling of control channels (PDCCH, PUCCH)
• Xn interface
• RRC improvements

About the Model

The model is being developed and maintained by the Mobile Networks group CTTC (Centre Tecnològic de Telecomunicacions de Catalunya). Its development was initially funded by InterDigital, later continued with funding from the Lawrence Livermore National Lab (LLNL) and a grant from the National Institute of Standards and Technologies (NIST), and now continues with funding from Facebook.

Documentation

The documentation for NR is available in the docs/manual of https://5g-lena.cttc.es

The documentation for NR V2X is available here (Section 2.16): https://5g-lena.cttc.es/static/archive/NR_V2X_V0.1_doc.pdf