Part of the reported performance assessment has been conducted with our custom-made system-level simulator, named WINTERsim, which has been extensively utilized recently for studying various IoT scenarios.
WINTERsim does not target any specific setting for any specific technology. It is more a library than an actual simulation software, which means that pretty much anything that has to do with delivery of packets can be rather naturally incorporated into WINTERsim. This makes the simulations smaller, more agile and easy to support in a quickly-changing environment.
Last version of WINTERsim source files are distributed under CC BY-NC-ND 4.0 license available via this link.