Clipping for Faster Wireless Network Simulation in ns-3

In this work we present the concept of 'clipping', scheduling receive events for wireless transmissions only on receivers within some distance of the transmitter. Combined with spatial indexing, this technique enables faster simulation of large-scale wireless networks containing tens of thousands or even hundreds of thousands of wireless nodes. We detail our additions and changes to ns-3 to implement this feature, demonstrate how it yields a 2x speedup for a complex 5G scenario with minimal impact on simulation fidelity, and show how under special circumstances a speedup of over 40x is achievable while producing identical results.