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Mesh networking when the cell network fails

Interesting article about a new plan for mesh networking Android phones if the cell network fails. I point this out because of another blog post of mine from 2005 on a related proposal from Klein Gilhousen that he was pushing after Katrina.

The wifi mesh has the problem that wifi range is not going to get much better then 30-40m, and so you need a very serious density of phones to get a real mesh going, especially to route IP as this plan wishes to. Klein’s plan was to have the phones mesh over the wireless bands that were going unusued when the cell networks were dead (or absent in the wilderness.) The problem with his plan was that phone tranceivers tend to not be able to transmit and receive on the same bands, they need a cell tower. He proposed new generations of phones be modified to allow that.

But it hasn’t happened, in spite of being an obviously valuable thing in disasters. Sure there are some interference issues at the edges of legitimate cell nets, but they could be worked out. Cell phones are almost exclusively sold via carriers in the many countries, including the USA. They haven’t felt it a priority to push for phones that can work without carriers.

I suspect trying to route voice or full IP is also a mistake, especially for a Katrina like situation. There the older network technologies of the world, designed for very intermittent connectivity, make some sense. A network designed to send short text messages, a “short message service” if you will, using mesh principles combined with store and forward could make sure texts got to and from a lot of places. You might throw in small photos so trapped people could do things like send photos of wounds to doctors.

Today’s phones have huge amounts of memory. Phones with gigabytes of flash could store tens to hundreds of millions of passing (compressed and encrypted) texts until work got out that a text had been delivered. Texts could hop during brief connections, and airplanes, blimps and drones could fly overhead doing brief data syncs with people on the ground. (You would not send every text to every phone, but every phone would know how many hops it has been recently from the outside, and you could send always upstream.) A combination of cell protocols when far and wifi when close (or to those airplanes) could get decent volumes of data moving.

Phones would know if they were on their own batteries, or plugged into a car or other power source, and the ones with power would advertise they can route long term. It would not be perfect but it would be much better than what we have now.

But the real lament is that, as fast as the pace of change is in some fields of mobile, here we are 7.5 years after Katrina, having seen several other disasters that wiped out cell nets, and nothing much has changed.