(wi-fi multiplayer wasn't built-in the game until tri, and it wasn't *really* the ironed out until the last couple of games. So to play not alone, you first had to download an obscure app from the ps3 market, figure out how to connect your psp to it, AND PRAY someone was awake and interested in helping out with your baby-quests)
tl;dr be thankful wifi is built in and that SOS mode exists because it sure as hell didn't before