Telepocalypse

Whatever happened to the Energizer Bunny?

The idea of an energy crunch seems to be getting some more exposure. This has an interesting long-range repercussion on telecommunications. The obvious stuff is that you have a lot more demand for telecom since moving bits is a substitute activity for moving atoms. The less obvious impact is the type of telecom you get.

Smart networks require energy to run. In the absence of commercialized reversible computation technology, every time you turn a 1 into a 0 inside a silicon chip you need to discharge some energy as heat. The Internet has a pretty hefty energy requirement. The energy bill will start to matter more and more, since it scales linearly with the number of bits transmitted through an electrical or optoelectrical system.

This points us towards the Gilderean future of all-optical networks. Optical switching is the end destination in terms of dumb pipes. (Unless you have some insight into superstring theory and data transmission via parallel universes we haven’t seen yet — but the evidence points away from this at the moment.) The energy needs are much lower — one photon per bit.

For wireless, it also means mesh networks offer more than convenience and low cost. Whilst directional antennas help, ultimately you’re radiating energy over a roughly R^2 area with any wireless transmitter. A sequence of mesh nodes radiate your bits over a smaller area. (Think of a sequence of overlapping lily pads in a bigger pond. The pond is a traditional cell tower. The lily pads are mesh nodes. A path from A to B covers only a few lily pads with energy, not the whole pond.) The question is, though, does the increased energy cost of routing the meshed bits nullify the lowered energy cost of transmitting them?

If energy gets really expensive and the number of bits to be sent increases dramatically, we’re all going to get a lot more familiar with the information theory work of Claude Shannon over the next few years.

Interesting aside: quantum computing also appears to be fundamentally limited by the energy budget needs.