New release of the 5G-LENA NR open source network simulator


The ns-3 team of the Mobile Network group has recently released a new version of the 5G-LENA NR open source network simulator. This group actively designs, develops and maintains the open-source ns-3 simulation models of leading 4G and 5G 3GPP technologies, LTE (Long Term Evolution) and NR (New Radio). ns-3 is a research-oriented, discrete-event network simulator, written in C++. It is licensed under the GNU General Purpose License, version 2. ns-3 is the most frequently cited tool used in computer network research (in the IEEE and ACM Digital Libraries).

The LTE and NR models, commonly referred to as LENA and 5G-LENA, are already by one measure (academic citations) the leading packet simulation tools for 3GPP oriented network simulations. For example, Google scholar counts over 11000 publication counts to ns-3 LTE; while other LTE simulators have significantly fewer counts. The access to the 5G LENA NR models is handled directly by the ns-3 team at CTTC and has already been granted to over 700 institutions around the world, in industry, academia and governmental agencies.

LENA and 5G LENA combine a simulated channel and physical layer model with a full stack implementation of the LTE/NR RAN (Radio Access Network) and EPC (Evolved Packet Core) protocol stack that closely follows 3GPP specifications. Most of the current version of LENA was developed between 2010 and 2013 as part of an industrial project funded by Ubiquisys Ltd. (now part of Cisco) and carried out by CTTC. The work around the NR protocol stack was initiated in 2017 in the framework of a collaboration with Interdigital. The simulators have received funding from different companies and governmental agencies like the WiFi Alliance, Spidercloud Wireless, National Institute of Standards and Technologies (NIST), Lawrence Livermore National Lab (LLNL), Huawei Technologies, among others. Branches for NR-V2X and NR-U, LAA/LTE-U are also available.

The openness and multi-RAT (Radio Access Technology) characteristic of ns-3, which is inherited by LENA and 5G-LENA, make them suitable for studies where high fidelity simulations are required for scalable scenarios where multiple technologies coexist, or where reproducible results are needed. High interest is concentrated now in the potential of these simulators in the area of O-RAN where the use cases identified  as key target by the alliance in one of their defining white paper, can be already easily supported by 5G-LENA in its openly available version. Examples are handover management in NR/ NR V2X scenarios, traffic steering between NR/NR-U/LTE, RAN slicing, Dynamic Spectrum Sharing, etc.

Finally, LENA and 5G-LENA inherit some ns-3 unique features at higher layers, including a real-time
emulation mode, which allows code reuse on testbeds or real networks, and a capability to compile the source code of real applications and the Linux network kernel for direct use in the simulations. This capability dramatically reduces the gap between simulations and prototyping, allowing for code reuse
in the area of research, where products are not yet in the market.