Current and Future Trends in Open Source Network Simulator for Wireless Systems

The impressive standardization activities within the wireless arena require a high degree of interoperability, thus leading to open standards. Even though the benefits are evident for this, the overall system is usually more complex, with tightly coupled protocol interactions. For this reasons, the protocol suite optimization is still an open issue. In particular, it is essential to carefully investigate the overall resulting performance before industrial development and real-world deployment. Since a real testbed is often extremely costly, an Open Source network simulator can represent a valid alternative to real device development and testbed deployment for academic and industrial research goals. In this chapter, the most relevant simulation frameworks are introduced and compared in terms of the following capabilities: • To implement standard protocols in order to optimize the performance for a specific scenario; • To build an approximate (i.e., not overly detailed) model, both analytical or functional, of the scenario; • To allow system parameters modification; • To be capable of going beyond the standards, in order to propose amendments or new standards; • To test and evaluate application-level protocols or, more generally, applications. Afterwards, we focus on the ns-3 framework, describing its actual models for IEEE 802.11, IEEE 802.15.4 and LTE/LTE-A systems and pointing out the most relevant features of the simulator. To conclude, some relevant simulation examples are shown, together with concluding remarks, pointing out ongoing development efforts.