Nee Sern is...

really really sleepy

Friday, July 13, 2007

Damned if we do, damned if we don't


This news article reports residents in Penang protesting over the construction of a telecommunications tower near their residential areas. The interesting thing is that the tower has been built according to MCMC (the government regulator for Communications) standards and safety guidelines, and as a response to the vehement complaints of poor coverage by the residents themselves. So they want good phone coverage but don't want the tower in their backyards?

Let's take a technical look at the misinformation. According to these protesters, building the tower so near to their houses will cause a lot of radiation and thus affect health and cause cancer. Let's see. The maximum transmit power of the base station is normally 43dBm, or 20W. After passing through the combiners, filters, feeders and antenna system gain, the EIRP (effective isotropic radiated power) will be around 55dBm, which is approximately 320W. However, since the waves need to propagate through the space from the antenna to the ground level, there is some form of degradation in the signal strength according to the appropriate propagation model. Usually, the signal strength on the ground level deteriorates to a value of -40dBm (depending on the distance from the antenna), which translates to a wattage value of 0.0000001W!

If we want to be worried, we should be worried about our handphones. Our handphones have a maximum transmit power of typically 21dBm, or 0.13W. Since there is no feeder or combiner system, and the antenna gain is typically 0dB, the EIRP from the phone is also 21dBm. Now, considering the fact that we normally use the phone by placing it against our ear (which is like just next to our brain), we expect the loss contributed by our body to be around 3dB. This means that the amount of power that is reaching our brain is 18dBm, or 0.06W. Compare this to the 0.0000001W from the base station. The power received from the base station is miniscule compared to the power received from the phone.

Does this mean that the phone will cause cancer? There is no absolute proof, no confirmed research to indicate yes or no at this point. However, we tend to take conveniences for granted, without understanding first what the facts are. We look at the large telecommunication towers with their large antennas and we become frightened. We look at the small handphone which we use and we think nothing of its radiation.

Let's face it. We are already accustomed to a wireless world. We treat mobile communications for granted, sometimes without knowing the technology that makes it happen. Perhaps MCMC should educate the consumers on the basics of wireless communication technology, so that health scares that lead to pointless protests will be a thing of the past, and we can all progress into the future.

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