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Saturday, 14 May 2011


Inventions sweep the world with increasing frequency, as is only to be expected with an exponentially growing pool of inventors and an exponentially growing foundation of science upon which they can base their inventions.

One of the big sweeps is unquestionably the mobile phone.  Anyone over the age of thirty can remember a world without it, but for all of us that world seems impossibly distant and unconnected, both with itself, and with us.

The frequency-shift communication that makes mobile phones possible was famously invented by Hedy Lamarr.  Indeed, it is an interesting aspect of fame that her invention will probably turn out to be the one by which future ages will remember her.  Anyone in the 1940s would have been flabbergasted if they could have known that back then.  To them it would be as if a time traveler from 2500 were to tell us that Einstein will be principally famous for his haircut.  (Hedy Lamarr was called "The Most Beautiful Woman in Film"  by her biographer Ruth Barton; form your own judgement from the picture.)

Now all over the world dictators are beginning to tremble as ordinary people take an instrument they use for chatting, and with it scythe off trigger-happy riot squads at the knees with the deadlier weapon of documentary exposure.

But the weak point in the system is the service providers and their base stations.  The base stations are too vulnerable to being turned off by those dictators, and the companies succumb to injunctions to surrender up call records and the like.

However, now that we have open phones that we can program ourselves, those service providers and base stations should become redundant.  That is because every mobile phone can be a base station for others nearby.  If I make a call it would hop from phone to phone across the city, then maybe dive down a wi-fi connection a few miles away to emerge at another on a different continent and then to go hopping on to my interlocutor.  The nice thing about this scheme is that the bandwidth of such a system is proportional to the number of phones in a locality.  (To be pedantic, the bandwidth is proportional to the square-root of the density of phones in the locality.)  Just where you need a lot of bandwidth, there are a lot of phones.

There is a problem.  To preserve your battery, your optimal strategy is to be a parasite - to use the open network, but selfishly not to forward the links needed by others.  But this is easily remedied: the software in the other's phones simply tests your phone to see if it is programmed like that and - if it is - other phones don't give you your calls.  That way everyone is rewarded if they add their bit to the commonwealth.

The system could be fully protected using hard encryption, with friends Diffie–Hellman-swapping their public keys just as for encrypted e-mail.  No one in the middle could listen in.

And then what would we have?  We'd have a completely free universal phone system that no company or government could shut down, and in which anonymity and untraceability would be preserved.  All you would have to buy would be the phone and electricity needed to charge its battery.


chris said...

If we had decent mobile infrastructure in the first place there wouldn't be any problems. If we built proper fibre broadband networks instead of trying to get internet access through old copper phone lines every connection could give out wifi and connectivity would be ubiquitous and cheap as chips. a real digitalbritain.

Anonymous said...

The idea of not forwarding any calls if you don't choose to direct calls is kinda punishing and evil.

Anonymous said...

Of course, IF you'd still be able to RECIEVE calls, but not MAKE them (in the parasite mode) THEN the system would be ok. ELSE, go back to the drawing board, OR figure out how to make the battery last longer WHEN parasite mode = off.

Valdis said...

It is not only dream but reality. See for example:

PhilT said...

The bandwidth isn't proportional to the number of phones if you're using WiFi, it's fixed. They can only communicate on the same channel with 20 MHz of bandwidth.

The idea requires a continuous path of phones from caller to callee or to internet access point, how often is that available ? It's hard to make mesh work multiple hops in static scenario with proper aerials let alone in ad-hoc dynamic situation.

Adrian Bowyer said...

I don't know how close two phones need to be to communicate. A phone can talk to a base station 2 km away, but the base stations are obviously both more powerful and more sensitive than a small phone. However, suppose it is half a kilometer.

Now imagine a one-kilometer disc centred on every phone on Earth and think of their overlap pattern. There would be no shortage of wi-fi hot-spots to route the odd long distance call. And the bandwidth needed for speech is tiny.

About a decade ago someone told me that a static wi-fi mesh was set up in East Berlin after the wall came down because there was so little wired communications. It was that that gave me the idea.

I don't see why it would be "punishing and evil" to refuse to connect people who refused to act as relays. It is simply a game-theoretic solution to the Tragedy of the Commons that would happen without it. And anyone would be free to turn their phone off...

Unknown said...

Oddly enough, such a system was proposed in the early eighties by Rudy Rucker in his novel "Wetware".

The reason this system comes about is that a mould descends from the moon and promptly eats all earthly transistors. Fortunately, there is an alternative technology based on stuff called impolex. Willy the hacker gets fed up using it to fix telephone exchanges and so releases the uvvy as an open source mobile phone. All you need is a chunk of impolex and a quick borrow of an existing uvvy. Willy gives away a few dozen, and the system builds itself up from there.

I encourage everyone to read his stuff, fiction as well as non-fiction. In particular, the novel "Postsingular" as the best take on The Singularity that I've seen.

Tom Gundry said...

Instead of choosing whether or not you forward calls, the phones could automatically pick which phones to use for the transfer based on the amount of battery left. So people's batteries will equalise.

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