New Cell Network Doesn't Depend on Towers
|David Rowe at Village Telco and The Serval Project|
The infrastructure that keeps cell phones and landlines buzzing is often the first casualty of a disaster, cutting off survivors at a time when communication is most crucial. Now, Australian researchers say they can solve that problem with mobile telephone networks that don’t require cell phone towers or other vulnerable equipment.
The system, dubbed “Serval” after a species of resourceful African wildcat, relies on Wi-Fi-enabled mobiles to turn each phone into an independent router. Any two phones with the Serval software can automatically create a temporary network, allowing voice transmissions without having any data travel through a cell phone tower. [Read "Low-Radiation Cell Phones: All the Rage? ."]
“It’s about bringing convenient and flexible telecommunications into situations where ordinarily it would be very difficult to do that,” said Paul Gardner-Stephen, a computer scientist at Flinders University in South Australia who heads the Serval Project.
Gardner-Stephen and his colleagues tested the phones July 9 in the wilderness north of Adelaide. Despite a complete lack of cell phone coverage, they were able to make calls to phones within a few hundred meters, simulating the type of network needed in a wilderness rescue scenario or in the aftermath of a disaster in a small village, Gardner-Stephen said.
Presently the phones can make calls only to nearby phones that run Serval software.
The system works using typical Wi-Fi-enabled phones. In this case, the team used Google’s Android phones, modifying them with mesh network software that enables the phones to self-organize into temporary networks. Additionally, the team developed software they call Distributed Numbering Architecture (DNA for short) that allows users to pre-assign their usual mobile phone number to their phone in the temporary network. That way, Gardner-Stephen said, people always have access to their usual contacts in case of a disaster.
The team is also working to develop a system of miniature phone towers, weighing no more than 22 pounds (10 kilograms) each, that could be parachuted from airplanes after a disaster such as the Haiti earthquake. The towers, which would cost about $1,000 apiece, would have a battery life of a few days, enough to keep communications running while permanent networks were repaired, Gardner-Stephen said.
The team is discussing a partnership with Red Cross New Zealand and is looking to work with other non-governmental organizations and telecommunications firms to improve the technology. With adequate funding, Gardner-Stephen said, the mesh network system could be operational in 18 months.
The temporary networks aren’t as high-quality or long-range as permanent, tower-based networks, so they’re unlikely to replace the current system in the developed world. But, Gardner-Stephen said, developing countries often lack coverage, especially in rural areas. Using recycled handsets fitted with Serval technology could be a cheap way to bring telecommunications to those areas.
“We can help cover black spots in the First World and provide people with free short-range telephone technology,” Gardner-Stephen said. “But also, the technology helps rather than leaves behind the poorest people in the developing world.”