A self-organising peer-to-peer cell-based wi-fi network

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-- Main.AdrianBowyer - 02 Mar 2006

The Open Phone

A self-organising peer-to-peer cell-based wi-fi network

TuxPhone is a project to develop an open-source cellphone. See also this article in Wired magazine.

In the February 2006 issue of the journal Communications of the Association for Computing Machinery there was an article by Damsgaard et al. bemoaning the fact that free wireless networks are subject to the tragedy of the commons - more and more people use the free resources until traffic gets so clogged that the network becomes useless.

I immediately realised that there is a stable game-theoretic solution to this problem; I doubt that I am the first to do so.

Consider a wireless network in which each node has the following characteristics:

  • 1. It attenuates its power in proportion to the proximity of its other interlocutor, like a cell-phone;
  • 2. It acts as a hub and a router for its neighbours in its own right; and
  • 3. It experimentally interrogates any new node to ensure that it conforms to characteristics 1 and 2. If the new node does not, its signals are not relayed.

A network of nodes with these characteristics can grow virtually without limit, as adding new nodes also adds bandwidth. And selfish attempts to insert nodes that do not act as repeaters are automatically rendered pointless.

The result is a commons the acreage of which grows with every cow that comes to graze.

Any network could be set up this way, but the obvious thing to do it with is wi-fi Internet, with interfaces wherever possible to the existing wired Internet. This could be used both for computers, or just for a mobile phone consisting of a microcontroller, a wi-fi card, and some Voice-over-Internet software.

Clearly such a phone could be made by RepRap from an open design distributed on the web.

Both computers and phones would need to use strong encryption to ensure privacy. It occurs to me that almost everyone with whom you might want to have a private phone conversation will be someone you will probably come into actual contact with, and so the phones could be made to do public key exchange over a physical connection (just touch a pair of contacts on the two phones together), making it particularly secure.

Further reading

Mesh networking (topology) is a type of networking where each node must not only capture and disseminate its own data, but also serve as a relay for other nodes, that is, it must collaborate to propagate the data in the network. --Wikipedia.