coondoggie passes along this excerpt from Network World: "Today I bring you a story that has it all: a solar-powered, low-cost, open source cellular network that's revolutionizing coverage in underprivileged and off-grid spots. It uses VoIP yet works with existing cell phones. It has pedigreed founders. Best of all, it is part of the sex, drugs and art collectively known as Burning Man. ... The technology starts with the 'they-said-it-couldn't-be-done' open source software, OpenBTS. OpenBTS is built on Linux and distributed via the AGPLv3 license. When used with a software-defined radio such as the Universal Software Radio Peripheral (USRP), it presents a GSM air interface ("Um") to any standard GSM cell phone, with no modification whatsoever required of the phone. It uses open source Asterisk VoIP software as the PBX to connect calls, though it can be used with other soft switches, too. ... This is the third year its founders have decided to trial-by-fire the system by offering free cell phone service to the 50,000-ish attendees at Burning Man, which begins today in Black Rock City, Nevada. "