By a lot. On the plus side, all the specs to create a component in a cellular network(protocols, procedures, network architecture and so on). are open and free.
On the other hand, the specs that cover all the parts of a cellular system is _many_ thousands of documents - and there's patents hidden in quite a lot of them.
> without much hope of a community reverse engineering a solution.
* specs for the chipsets are not available.
* You might get the spec. for the pinouts for the chips if you sign an NDA, but not the specs for being able to run your own code on it.
* But the chipset manufacturers won't talk to you unless you're serious about buying quite a few million of them anyway.
http://bb.osmocom.org/ have managed to reverse engineer an old GSM chipset (with help from leaked documents and source code) and created an open source GSM base band for those old phones. But there's little to suggest doing the same for 3G or 4G will be possible in the near future.
By a lot. On the plus side, all the specs to create a component in a cellular network(protocols, procedures, network architecture and so on). are open and free.
On the other hand, the specs that cover all the parts of a cellular system is _many_ thousands of documents - and there's patents hidden in quite a lot of them.
> without much hope of a community reverse engineering a solution.
* specs for the chipsets are not available.
* You might get the spec. for the pinouts for the chips if you sign an NDA, but not the specs for being able to run your own code on it.
* But the chipset manufacturers won't talk to you unless you're serious about buying quite a few million of them anyway.
http://bb.osmocom.org/ have managed to reverse engineer an old GSM chipset (with help from leaked documents and source code) and created an open source GSM base band for those old phones. But there's little to suggest doing the same for 3G or 4G will be possible in the near future.