Enabling Heterogeneous 5G Simulations with SDN Adapters Thien Pham (B ) , Jeremy McMahon, and Hung Nguyen Teletraffic Research Centre, The University of Adelaide, Adelaide, SA 5005, Australia {thien.pham,jeremy.mcmahon,hung.nguyen}@adelaide.edu.au Abstract. 5G networks are expected to consist of multiple radio access technologies with a Software-defined networking (SDN) core, and so sim- ulating these networks will require connecting multiple subnetworks with different technologies. Despite the availability of simulators for various technologies, there is currently no tool that can simulate a complete het- erogeneous 5G network. In this work, we develop a novel SDN adapter to enable seamless inter-working between different simulation/emulation tools, such as NS-3, Mininet-WiFi, Omnet++, and OpenAirInterface5G. Using the adapter, we have built a large scale 5G simulator with multiple networking technologies by connecting existing simulators. We show that our adapter solution is easy-to-use, scalable, and can be used to connect arbitrary simulation tools. Using our solution, we show that Mininet- WiFi exhibits unreliable behaviour when connected to other networks. We compare our solution against other alternatives and show that our solution is superior both in terms of performance and cost. Finally, and for the first time, we simulate a large heterogeneous 5G network with all of the latest technologies using only a standard commodity personal computer. Keywords: Simulation · Cross domain · Interoperability · Network slicing · SDN · NFV · LTE · 5G NR 1 Introduction 5G networks will consist of multiple radio access technologies along with a Software Defined Networking (SDN) core to allow for a large number of end devices and flexible network deployment. A typical complete 5G is illustrated in Fig. 1 [4, 5, 24, 25]. In this network, we have an SDN core where network func- tion virtualization and network slicing are used to provide different services to different end users. Multiple access technologies such as WiFi-6, LTE, and 5G New Radio are being, and will be, used to connect end devices to the core. Emulation software such as OpenAirInterface5G (OAI5G) [19] and srsLTE [14] have been used to evaluate the performance of 5G networks. They are, however, resource demanding and require actual RF transmission over the air c  ICST Institute for Computer Sciences, Social Informatics and Telecommunications Engineering 2020 Published by Springer Nature Switzerland AG 2020. All Rights Reserved H. Gao et al. (Eds.): TridentCom 2019, LNICST 309, pp. 163–183, 2020. https://doi.org/10.1007/978-3-030-43215-7_12