Economical GSM base station using free software
The new GSM Base Transceiver Station sysmoBTS from German company sysmocom offers a way to expand the coverage of GSM mobile phone networks. The device is described as suitable for use on ships or at events, for testing of GSM/EDGE equipment, or for the operation of rapidly deployable private networks. In urban areas, the small appliance could also provide better indoor coverage. Sysmocom is also in contact with suppliers in Africa and Latin America who want to supply a solar-powered mobile sysmoBTS for rural regions.
According to the data sheet, the 165mm×125mm×59mm unit is able to operate on GSM 850/900/1800 and 1900 bands with 10W power consumption and passive cooling. The unit also has 128MB of Flash, 100Mb Ethernet and a microSD socket. It can handle 14 concurrent calls and process up to 60 simultaneous SMS messages.
While the ARM-based hardware is not open, the sysmoBTS software is available as source code. This includes the Yocto/Poky embedded Linux distribution, U-boot, all the kernel modules, the protocol implementation and the osmo-bts OpenBSC software. Sysmocom was founded by Harald Welte, who is well known for his work with GSM and open source, and Holger Freyther. The sysmoBTS price is dependent on "your overall project / volume" and is available on request; evaluation kits are already available.
To operate the device, however, you would need a licence, and in the UK these are somewhat difficult to obtain. In Germany, licences are handled by the Federal Network Agency who can grant permanent, research and development or event licences. In the UK, licences can be obtained through OFCOM, though the process is complex. GSM operations on ships in international waters require no licence.
The H recently carried an article on Building a GSM network with open source which covers the background and history behind devices such as the sysmoBTS.