Things You'll Need
Instructions
Preparing Your Computer
Verify that a USB wireless modem is connected via a USB port and functions by attempting to access the Internet. Connect an ethernet cable from your computer to your PS3. This may seem counterintuitive, but the PS3 does not possess the appropriate drivers to interpret a USB wireless modem. The goal is to use the computer as a gateway, router or interpreter for the connection.
Open the panel that manages network connections on your computer. On Microsoft Windows XP, it is labeled "Connect To;" and it is labeled "Network and Sharing Center" on Microsoft Windows Vista and later Microsoft operating systems. Right-click on your USB modem's connection, and select Properties. Go to the Advanced, or Sharing, tab, and check the box marked with: "Allow other users to connect through this computer's internet connection."
Allow your Internet connection to reset if necessary. Older operating systems such as XP may require this task.
Configuring Your PS3
Start your PS3. On the main screen, go to the "Settings" section. Under that tab, go to the "Network Settings" section. From there, select "Internet Connection Settings."
Select "Yes" when prompted with this warning: "If you perform Internet connection settings, the system will be disconnected." Then, select "Easy." A number of tests will perform, and then you will be asked to select several options. Choose the default option for each option. After you are done, the PS3 will test the Internet connection.
Allow the PS3 to complete calibrating the Internet settings. Afterward, log into the PlayStation Network and the PlayStation Store. If you can log into them, try playing multiplayer in your favorite game.