I have mixed emotions when I read something like the following which appeared on Slashdot earlier today, especially given the known GSM interference problems.
However, this is telephony and this is news (from Slashdot):
Harald Welte, who's been interviewed previously by Slashdot, has written on his blog about operating an Open Source GSM network:
at the recent HAR2009 conference:
Photographs and a description and of the setup, run under license of the Dutch regulatory authority, are provided; essentially the setup consisted of a pair of BTSs (Base Transceiver Stations) running at 100mW transmit power each and tied to a tree. In turn these provided access to the Base Station Controller (BSC), in this case a Linux server in a tent running OpenBSC:
The system authenticated users with a token sent via SMS; in total 391 users subscribed to the service and were able to use their phones as if they were on any other network.
Independent researchers are increasingly examining GSM networks and equipment, Welte's work proves that GSM is in the realm of the hackers now and that this realm of mobile networking could be set for a few surprises in the future.
[ We need to keep an eye on this; "a few surprises" could mean many different things :-) ]