Indeed, hardware is the key. You can't run a GSM base station without a good SDR transceiver attached to your PC. :)
In 2009 when we tried to launch OpenBTS with a USRP1 (Osmocom didn't work with SDR back then), it just didn't work and we had to spend days figuring out why and we had to solder a better clock to it to get it working. Today you have a selection of inexpensive SDR devices (B200, BladeRF, UmTRX.org) which let you run a GSM stack at home and LimeSDR is a great progress in this direction, especially given it's OSHW.
Note: always know the laws and check your local spectrum regulation policies if you want to run a GSM station. In most countries you need to get a license to do that even for educational/research purposes.
I also strongly discourage everyone from attaching any amplifiers to the aforementioned boards yourself. Even if you think you're sure you're not disrupting anything. Amplifiers will amplify all noise and spurs generated by your transceiver including ones in other bands you do not expect. So you may (and most likely will) interfere with other services. If you need a high power base station (and you have a license to run it) - get a commercial BTS which is tested to meet requirements and avoid interference. I can definitely recommend our UmSITE (shameless plug), but there are a number of other companies selling commercial BTSes.
If you're not interfering with existing services and run your BTS in a closed mode, 911 is not a concern, because a GSM BTS broadcast channel has a bit which indicates 911 service availability and all open-source GSM software disable this by default. So phones won't camp on your BTS for emergency services. To avoid interference you really should be running at low power like 1mW (on SDRs like UmTRX which have pretty high power by themselves you can easily reduce the power to a reasonable level) and use an unused ARFCN. Make sure to do a proper scan with fosphor/SDRangeLove to see traffic-only channels. Usual scan tools will give you a list of beacon (BCCH) channels, but will miss all TCH-only ones,
We're also partnering with Lime Microsystems (people behind LimeSDR) to create a next gen inexpensive embedded SDR - so you could turn an application you developed with LimeSDR into an industrial/embedded product easily. Check out http://xtrx.io for details.
Indeed, hardware is the key. You can't run a GSM base station without a good SDR transceiver attached to your PC. :)
In 2009 when we tried to launch OpenBTS with a USRP1 (Osmocom didn't work with SDR back then), it just didn't work and we had to spend days figuring out why and we had to solder a better clock to it to get it working. Today you have a selection of inexpensive SDR devices (B200, BladeRF, UmTRX.org) which let you run a GSM stack at home and LimeSDR is a great progress in this direction, especially given it's OSHW.
Note: always know the laws and check your local spectrum regulation policies if you want to run a GSM station. In most countries you need to get a license to do that even for educational/research purposes.
I also strongly discourage everyone from attaching any amplifiers to the aforementioned boards yourself. Even if you think you're sure you're not disrupting anything. Amplifiers will amplify all noise and spurs generated by your transceiver including ones in other bands you do not expect. So you may (and most likely will) interfere with other services. If you need a high power base station (and you have a license to run it) - get a commercial BTS which is tested to meet requirements and avoid interference. I can definitely recommend our UmSITE (shameless plug), but there are a number of other companies selling commercial BTSes.
If you're not interfering with existing services and run your BTS in a closed mode, 911 is not a concern, because a GSM BTS broadcast channel has a bit which indicates 911 service availability and all open-source GSM software disable this by default. So phones won't camp on your BTS for emergency services. To avoid interference you really should be running at low power like 1mW (on SDRs like UmTRX which have pretty high power by themselves you can easily reduce the power to a reasonable level) and use an unused ARFCN. Make sure to do a proper scan with fosphor/SDRangeLove to see traffic-only channels. Usual scan tools will give you a list of beacon (BCCH) channels, but will miss all TCH-only ones,
We're also partnering with Lime Microsystems (people behind LimeSDR) to create a next gen inexpensive embedded SDR - so you could turn an application you developed with LimeSDR into an industrial/embedded product easily. Check out http://xtrx.io for details.