Wireless experts from PA Consulting have used a Raspberry Pi to run a mobile phone basestation that operates a private network.
The team hooked the Raspberry Pi up to a radio interface and, using Open Source software, implemented the functionality of a mobile basestation. Along with two mobile phones with sim cards, PA created all the functionality to make the phones talk to each other. PA set up its Raspberry Pi in a screened room to ensure no laws on frequency spectrum were broken. Frazer Bennett, a technology expert with PA, said: "We've shrunk a 30ft basestation into a 3in Raspberry Pi and created our own mobile phone network. This proves what can be achieved through low cost off the shelf systems." To create the basestation, PA: • set up a Raspberry Pi in a screened room to ensure it didn't break any laws on frequency spectrum • hooked up the Raspberry Pi to a radio interface • hand optimised some software, and • code optimised the signal processing The Raspberry Pi was used to run three pieces of software: • OpenBTS, which implements the GSM mobile phone standard • FreeSWITCH, this routes calls in a similar way to Skype, and • a programming script that assigns telephone numbers.