I am playing Pokemon Diamond on Desmume and have a few Pokemon in my team that can only be evolved through trading. For the guides I found online that teach how to do trading using a emulator, all of them involves simulating a wifi connection and connect to GTS. However, GTS has been shutdown for generation IV already. So this method is no longer working.
I heard that if I have 2 real NDS in a close range (e.g. in the same room), I can still trade Pokemon on generation IV by using friend code. Is this true? And how can I simulate that using emulator (not restricted to Desmume)?