TerraNet has been giving more details about how it plan to fulfil its mission of bringing mobile telephony to the four billion people who have no access to telephony.
The plan is to enable people to make phone calls by establishing a direct link between their devices that doesn't need a base station. TerraNet's founder Anders Carlius argues that infrastructure is the greatest investment involved in the usual way of providing telephony, yet it is hard for an operator to recoup that investment from very poor people who will use their phones as sparingly as possible.
The TerraNet system relies on adapted handsets that also serve as nodes between other handsets, extending the reach of the entire system. When a TerraNet phone is switched on, it looks for other phones. If it finds them, connects, thereby extending the radio network. When a number is dialled, a handset checks to see if the person being called is within range. If they are, it hands-off the call.
While each phone has a maximum range of 1km, according to Carlius, every handset can hand-off seven calls at the same time and each call can comprise a maximum of seven hops before the transmission delay becomes too great. This so-called collaborative routing of calls means the phone calls between handsets are free.
Carlius said a prototype handset is ready and orders taken, although he wouldn't say exactly when the handsets would go into volume production.
He also pointed out that, unlike their richer counterparts, the people the service is designed for typically don't move very far in a typical day.
A number of obstacles remain, including a lack of available spectrum and naturally the world's mobile network operators are not keen on seeing their cherished business model trampled in the dirt. Also, battery power looks likely to be an issue, given that someone's phone could be in use a great deal, without them making a call, as well as the amount of power a device consumes and radiates by acting as a transmitter.
Illiteracy is another knotty problem - if you can't read letters and numbers it's all but impossible to use a normal mobile phone. Carlius has ideas about that too, such as displaying pictures of contacts instead of their names and numbers, and simple, three button operation.
Mobile phone and equipment maker Ericsson has invested some £3million (€3.7 million) in TerraNet, according to the BBC.