It doesn't take much digging to figure out what's triggered this renewed interest in mesh networking: the NSA PRISM program and that whole galaxy of still-unfolding developments that have left a great many people uneasy about their privacy and uncertain about their government. People want a network they can control, and mesh networking sounds like it might be the answer.
[Find out what Network Computing readers think about the NSA's data gathering program in NSA PRISM Violates Rights, Fails to Protect, Say Readers]
To be precise, there seems to be a convergence of two technologies in the works: P2P and mesh networking. Both are about decentralizing the way networks work, but each is a different aspect of the problem. P2P is about the protocols and the interactions between the clients; mesh networking is about the clients themselves being the network fabric.
But it's mesh networking that has my attention now, because once again people seem to be asking a key question: If we're all walking around with wireless devices in our pockets, doesn't it make sense to build our network infrastructure on top of the mass of those things, instead of a few towers or access points here and there?
It's a good question, and it goes to the heart of why mesh networks exist in the first place--as a way to flexibly extend networking into places where it isn't always practical to deploy it. Areas that can't be covered by a traditional tower can be covered by a mesh, and there are plenty of existing real-world examples of this.
Firetide, for instance, implements and sells mesh networking technology for municipal and business use. ZigBee uses low-power transceiver technology to set up mesh networking between devices that use very small amounts of data, like traffic management systems or in-home sensors.
The real next-generation mesh networking dream, though, could be expressed as "every cellphone is a cell tower," where the devices we carry with us extend the network automatically.
I actually heard a variety of this proposal in the 1990s, back when cellphones were first taking off with the public but coverage remained spotty (and was largely analog). If your signal to the nearest cell tower was weak, the phone could "piggyback" onto the signal available from phones in the vicinity, and thus boost its signal by proxy, hopscotching data across other phones. Many of the current indie mesh network projects, such as Meshbox and Roofnet, are analogues of this concept.
It's a cool idea. But at the time, it was massively impractical for a whole host of reasons, not least was the bandwidth restrictions that go with any such mesh network.
The other problem is that the underlying reason for wanting such a thing--poor coverage by conventional cell networks--is a lot less of an issue now. Verizon, for example, created live heat maps of coverage in major metropolitan areas, based on the signals it was getting from people's phones. This let Verizon figure out where dead zones of one kind or another existed--possibly because of signals bouncing off of the faces of buildings or the like--and add towers in places that actually helped.
In other words, mesh networking "for the people" may not be the best use for it. It might be easier, and more universally beneficial, to improve the existing towers and access points--and the radio standards used by the phones we carry--than to try and create a decentralized peer-to-peer substitute for the infrastructure we already have.
That said, I can think of plenty of reasons why it would be good to have something like this as a fallback. In the event of a natural disaster, for instance, it would be useful to have some kind of ad hoc mesh networking that kicks in on cellphones as a way for emergency services to send messages or to allow people to confirm they're O.K.
So what about privacy and personal freedom? It's not impossible to envision a future where we have two Internets--the one we all plug into and a second one created via an ad hoc assembly of devotees and hobbyists, all working loosely in unison much the same way the old FidoNet did. My money is on the first on being the most useful, but I wouldn't count out the second one being a force for innovation in its own way.