Insert your SIM card in your modem, connect it to your PC and launch Mobile Partner. If you don't have the software installed on your computer, you can download and install it free of charge from the official web page. After that, press the Call icon to open the dial pad, type the number you want to call and press the green dial button:
You can receive calls the same way. You need only to make sure that the modem is connected with your PC.
Note: If you can't use your SIM card with your modem model, you will need to unlock the device.