Simulation research on VDL2 system link transmission performance

In order to verify the performance of aviation VHF Data Link Mode 2(VDL2) system that will be used in the next generation civil aviation in China, the physical layer and link layer models of VDL2 system based on OPNET are built first used for parameter simulation. Then, the effect of aircraft number on the average retransmission delay is simulated. The effects of offered load on the average subnet delay, the probability of successfully sending data packet, and the system throughput are further testified. The simulation results demonstrate that if the offered load is no more than 0.65, VDL2 system subnet delay can meet the requirement, throughput is raised significantly with the offered load increasing and the probability of successfully sending packet can reach to 80 percent. The results can be taken as an important reference to future practical application of VDL2 system.