How to Reduce Cell-Phone Radiation Exposure

Bron: www.technologyreview.com/view/414222/how-to-reduce-cell-phone-radiation-exposure/ .
2 juli 2009

Een halve oplossing, maar de zendmasten blijven even hard stralen.

A new network architecture could dramatically reduce the radiation exposure from cell phones.

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.

Oorspronkelijk artikel:
arxiv.org/abs/0906.5289

Green Cellular - Optimizing the Cellular Network for Minimal Emission from Mobile Stations

Doron Ezri, Shimi Shilo
(Submitted on 29 Jun 2009)
Wireless systems, which include cellular phones, have become an essential part of the modern life. However the mounting evidence that cellular radiation might adversely affect the health of its users, leads to a growing concern among authorities and the general public. Radiating antennas in the proximity of the user, such as antennas of mobile phones are of special interest for this matter. In this paper we suggest a new architecture for wireless networks, aiming at minimal emission from mobile stations, without any additional radiation sources. The new architecture, dubbed Green Cellular, abandons the classical transceiver base station design and suggests the augmentation of transceiver base stations with receive only devices. These devices, dubbed Green Antennas, are not aiming at coverage extension but rather at minimizing the emission from mobile stations. We discuss the implications of the Green Cellular architecture on 3G and 4G cellular technologies. We conclude by showing that employing the Green Cellular approach may lead to a significant decrease in the emission from mobile stations, especially in indoor scenarios. This is achieved without exposing the user to any additional radiation source.



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