Instructions
Turn on each PlayStation 3 you are trying to connect to the wireless modem.
Select "Settings" on the menu of each of the two PS3s you are trying to connect.
Choose "Network Settings" on each of the two PS3 consoles.
Open the "Internet Connection Settings" window on each of the two PlayStation 3 consoles.
Choose "Easy" setup on your first PlayStation 3. Select "Wireless" and choose the listing for the wireless modem. Select the wireless modem's security type and input the password, if applicable. Repeat this step on the second PlayStation 3 to get that console online as well.