NetSim

NetSim, from Tetcos LLP in Bangalore, is a packet-level discrete-event network simulator that also works as an emulator, meaning it can be connected to real hardware running live applications rather than staying purely synthetic. Its coverage leans towards domains most general-purpose tools do not reach: 5G and 6G NR including massive MIMO and network slicing, non-terrestrial and satellite networks, and military tactical radio.

That defence and space orientation is the clearest reason to shortlist it. It models Satcom in Ku, Ka and X bands and dynamic TDMA in VHF, UHF, L, S and C bands, alongside more familiar Wi-Fi, IoT, WSN, VANET and SDN stacks, and supports cyber-attack simulation on power systems. Typical studies are coverage, capacity, throughput, latency and PRB utilisation. Tetcos reports 500+ organisations across 30+ countries and 20+ years of development, with v15.0 current. It runs on Windows and is licensed in Pro, Standard and Academic editions.