I know that you can play GameBoy Advance games on a DS -- there's another slot. But if one person has Pokemon Emerald in his DS and the other has Pokemon Ruby in his, can they trade Pokemon wirelessly?
if your saying that trading on the ds no.But get pokemon diamond or pearl and win the game go to prof.rowan's ab and he'll tel you about pal park then get the pokemon from emerald then catch them then you can Trade.(the person you wnt to trade has to do this to)its difficult