There are a variety of mPCIe USB modems available providing 4G/LTE functionality. When connected mPCIe modems present several communication ports as interfaces, including:

• Serial port(s) for communicating with the modem via AT commands
• Optional additional port for a GPS feed (if supported)
• More recent models also have the faster direct QMI interface

OS Support for most mPCIe modems is included within the Linux kernel, so no additional drivers are needed. The modem connects to the host via the mPCIe slot's USB connections and appears as several /dev/ttyUSB serial ports (and where applicable, QMI devices as /dev/cdc-wdm devices) after boot up.

For convenience, we provide pre-written udev rules for several modem types, which consistently create the following symlink shortcuts at each boot cycle:

To configure these symlinks, place the respective udev rule in /etc/udev/rules.d. The rules are mutually exclusive, so please only install the rule needed to match the installed modem type.

Important notes:

• LTE Modems for North America are often carrier locked and require matching firmware pre-loading before they will work. Specify the chosen carrier type (e.g., AT&T, Verizon) during the purchasing process to ensure compatibility with your chosen cellular network.
• Many modems cover different regions and LTE Bands. Double-check with your modem vendor which modem is most suitable for the target region.