NetSim has a protocol library for all simulation purposes including GSM, CDMA, LTE. Very useful for people who want to learn about the technology. The animations showing the packet details being forwarded is a plus. Recommended.
Presently using the latest v8 of NetSim which I must commend is awesome in terms of ease of use compared to the others. It seems they have also improved in their protocol library options. Editing /Creating new protocols are very easy now.