Here’s a simple idea for creating a cell-phone network that minimizes the radiation exposure for callers while maximizing the battery life of handsets.

Today’s cell-phone networks consist of base stations that both transmit and receive signals. The strength of the signals that a handset has to generate depends on how far away it is from such a base station. Obviously, handsets in smaller cells transmit at a lower power, reducing the user’s radiation exposure.

So in theory, you could reduce users’ radiation exposure from handsets by reducing the size of the cells that each base station serves. But in practice, that isn’t possible because people who live nearby naturally object to the constant exposure that a base station would expose them to.

But Doron Ezri and Shimi Shilo at Greenair Wireless, an Israeli startup, have dreamed up a way around this. Their idea is to enhance existing networks by adding large numbers of base stations that only receive signals and are connected up to the rest of the network via a landline or a line-of-sight microwave link.

This creates large numbers of microcells in which the handsets can transmit at low power while the existing base stations continue to do the transmitting. So during any conversation, the handset transmits to one of the new nearby base stations but receives from a more distant conventional base station.

And since the new base stations only receive, there shouldn’t be the same kind of objections to putting them up. At least that’s what Ezri and Shilo think.

Although the jury is still out on the health risks of mobile-phone radiation exposure, it seems wise to employ the precautionary principle whenever possible. Greenair is the startup that Ezri and Shilo have created to commercialize the idea, which should improve battery life to boot.

Good luck to them, but a word of advice: never underestimate the power of the NIMBYs.

Ref: arxiv.org/abs/0906.5289: Green Cellular–Optimizing the Cellular Network for Minimal Emission from Mobile Stations