Design and Implementation of 3GPP NTN Protocol Simulation Platform Based on NS-3

Non-terrestrial network (NTN) is a key enabler in 6G for achieving global coverage and integrated satellite-terrestrial communications. To address the limitations of existing simulation tools in 3GPP standards compliance and dynamic topology modeling, this study designs and implements a high-(cid:12)delity NTN simulation platform based on the ns-3 framework. The main contributions include: developing a dedicated NTN mobility model to support high-dynamic node trajectories such as satellites; extending the RRC (radio resource control) layer in the ns-3 NR module in accordance with 3GPP TS 38.331 to accurately emulate NTN connection management procedures; and implementing a full NTN protocol stack from the physical to the application layer to support end-to-end performance evaluation. Experimental results demonstrate that the platform can accurately simulate satellite constellation dynamics and NTN propagation delays, providing a reliable tool for research on key 6G NTN technologies.