3 ms·

This is really impressive. Even more so because at least for me GSM still has this mysterious "only the big guys can do it" feeling which IP, routing and server

by pilif 16y ago

This is really impressive. Even more so because at least for me GSM still has this mysterious "only the big guys can do it" feeling which IP, routing and servers lost a long time ago for me. Is this the beginning of GSM hacking for the normal people (for a loose definition of normal of course)?

ovi256 16y ago
This is really cool, and really, really illegal, like federal illegal, pound-in-the-ass illegal. Even owning such a hacked Droid is probably illegal, because it's unlicensed equipment that can use restricted spectrum. If you use it in a large metropolis, I'd expect you'd interfere with other operators basestations, and as soon as they figure it out, they'd be on you. And the FBI. Maybe the SWAT. Keep in mind that the GSM/CDMA spectrum was auctioned for billions to the operators. Update: someone mentioned a "developer's license" - a bit of research turns out something even better - some countries, like the Netherlands, allow unlicensed very-low-power base stations, up to 100mW, essentially pico- and femto-cells. Many Wifi routers have higher TX power than that. This will cover a room, a large hall, or an open air space large like a football stadium. No mention of a developer's license though, as this seems to cover its needs.
CaptainMcCrank 16y ago
It is interesting, but I think it is a dead end. The concept is possible because GSM doesn't require mutual authentication. Consequently, devices can "relatively" easily attach to a tower, if a bunch of circumstances are true. Umts requires mutual authentication, so any devices that will connect must be preconfigured to do so. This means that attaching to your own tower becomes a lot less simple: each device must be configured to work with your own cloud. I think it is a dead end because gsm will be phased out eventually. This is only "easy" today because many phones are dual stacked gsm/umts. OpenBTS really started some interesting work in this space, but I think openBSC is the more advanced (and less approachable) soloution. OpenBSC recently reported some small ability to support a little bit of GPRS. Without GPRS support, there is no ability to do data on your phoney tower. Unfortunately, the hardware on openBSC is less accessible.

by pilif 16y ago

ovi256 16y ago

This is really cool, and really, really illegal, like federal illegal, pound-in-the-ass illegal. Even owning such a hacked Droid is probably illegal, because it's unlicensed equipment that can use restricted spectrum. If you use it in a large metropolis, I'd expect you'd interfere with other operators basestations, and as soon as they figure it out, they'd be on you. And the FBI. Maybe the SWAT. Keep in mind that the GSM/CDMA spectrum was auctioned for billions to the operators. Update: someone mentioned a "developer's license" - a bit of research turns out something even better - some countries, like the Netherlands, allow unlicensed very-low-power base stations, up to 100mW, essentially pico- and femto-cells. Many Wifi routers have higher TX power than that. This will cover a room, a large hall, or an open air space large like a football stadium. No mention of a developer's license though, as this seems to cover its needs.

CaptainMcCrank 16y ago

It is interesting, but I think it is a dead end. The concept is possible because GSM doesn't require mutual authentication. Consequently, devices can "relatively" easily attach to a tower, if a bunch of circumstances are true. Umts requires mutual authentication, so any devices that will connect must be preconfigured to do so. This means that attaching to your own tower becomes a lot less simple: each device must be configured to work with your own cloud. I think it is a dead end because gsm will be phased out eventually. This is only "easy" today because many phones are dual stacked gsm/umts. OpenBTS really started some interesting work in this space, but I think openBSC is the more advanced (and less approachable) soloution. OpenBSC recently reported some small ability to support a little bit of GPRS. Without GPRS support, there is no ability to do data on your phoney tower. Unfortunately, the hardware on openBSC is less accessible.