Typically available as an external USB module, for desktop computers, the modem may also be available on a PCI or PCI Express (PCIe) card that plugs into an empty slot on the motherboard.

Taking up one PCI slot, it accelerated audio and modem functions in hardware. For audio and modem only, it could be built with a connector to plug into an AMR slot. For networking, the card used a ...

[delokaver] figured out how to use these 3G cards over USB instead ... on a four-wire USB cable. The modem relies on the 3.3V power from the Mini PCI-e slot instead of the 5V from USB.