SDR and NFV extensions in the ns-3 LTE module for 5G rapid prototyping

The virtualization of mobile network functions constitutes one of the main blocks for addressing the high flexibility requirements of fifth generation (5G) communication systems. Reconfigurable hotspots are expected to be massively deployed to enable on-demand services and dynamically adapt the network capacity according to traffic requirements. In this paper, we present the extensions and modifications of the long term evolution (LTE) module of the ns-3 simulator (LENA) to include a software defined radio (SDR) physical layer implementation. These extensions combine the native flexibility of the simulator with the SDR features of a real-time prototype. Moreover, the framework was designed to distribute the communication functions across different elements of the network with the possibility of adjusting several transmission parameters as in a network function virtualization (NFV) paradigm. Thanks to an emulated full network protocol stack, the prototype allows the experimentation of novel 5G solutions and the evaluation of relevant key performance indicators (KPIs) from the lower layer protocols up to application level. To this aim, we present the experimental evaluation of the KPIs of energy, latency, throughput and reconfiguration time in relevant scenarios.