At Endaga I worked on
a "programmable cell phone" testing system.
Endaga built really affordable cell phone towers and we wanted to be able to test our boxes with real phones creating real traffic. Eno used a Beaglebone Black and an Adafruit Fona (with an attached Endaga SIM card) to send messages and place calls.
The Beaglebone nodes ran a small command and control server, while the testing machine used a simple API to pass messages to the test nodes.
See more on github!