Edited by author 01-26-2004 09:19 PM
As far as I can calculate, Guy, the chances of anyone installing 60 Ghz devices within 300,000 known streetlamps in just four major cities in the UK is remote. If this ever happens within the 2-3 year timeframe I may even consider returning to Blighty from Canada. As for making every other street lamp a Node this will not take half the time! I actually do really like the idea of installing these first in speed limit signs on our crowded freeways and motorways as it will further snarl the traffic to a crawl making cycling on byroads even more popular! As far as the issue of "60 GHz transceivers generating more radiation," that is patently not true. As some are already saying the real culprits are the mobile cellular phone companies at the much lower frequencies of 0.9 and 1.8 Ghz. They know for sure that they are generating very dangerous radiation levels from one if not both ends of the links, the mobile handsets themselves and from existing cellphone tower sites. In my opinion this may in fact be the small straw that breaks the mobile cellphone carrier camel's backs far sooner than 2-3 years. If SIP phones and VoIP arrive in the next year then do not expect long distance to cost a penny more than local calls. A very nice class action suit will arrive soon on the cellphone companies desks from a large number of those cellphone users who have been found to have leukaemia. One, two or all three of these thorny issues will ultimately put a nail in the coffin and certainly within 2-3 years somewhere.
There is however a far more pressing concern to me behind all this radiation scare. It has been lurking as there appears to now be solid evidence against our kids ever being wise to use current models of mobile cellphones to talk for more than 30 minutes a day.
We should all be far more concerned with our children's frequent and almost continual use of mobile cellular phones. Current long term research into ionising vs non-ionising radiation is imminent and perhaps is a black art to some but surely we should err on the side of caution rather than ignore these known risks.
One should also look carefully at the actual transmitted and "stated" vs the "actual" radiated power emanating from the existing 2G and 2.5G and soon to be upgraded 3G mobile cell phone tower sites. The phones need to be looked at seeprately and very carefully as well. If one looks at the "actual" continual 24/7/365 radiation patterns emitted by these cellphone towers themselves one would be alarmed. That is "definable dangerous radiation" by all accounts and so living close to one is a risk. That tower is clearly transmitting at either 1900 MHz or at 900 MHz. It also has a far broader transmitted range of around 4km rather than the 60 or so meters of distance between the proposed street lamps. If we then look at the "actual radiated power" from an existing home given the increased use of unlicensed spectrum space around the home in the 5.8 GHz and 2.4 GHz spectrum bands (assuming the IEEE 802.11a/b/g WiFi standards) these devices compare with those same radiation power and the patterns of transmitting cellphones.
Now to the planned Street lamp and speed limit sign usage. Being a device radiating at around 60 GHz the "actual radiation levels" of these nodes on streetlamps are going to be far less! Not long ago a fascinating document emerged called "Performance Characteristics of 60-GHz Communication Systems". It was published as a .pdf file which i obtained in October 2002. It was published by a company based in Seattle in Washington State called Terabeam see URL at:
http://www.terabeam.com/tech/ I quote:
"... these 60Ghz devices must be certified in the USA as a new FCC Part 15 device, placing them in the same category as controllers for garage door openers. Under this new FCC part 15 certification, the 60 Ghz links are allowed to transmit a maximum average power of 9 µW/cm2. This threshold represents less than 1 percent of the power limits established by world standards organizations and the US federal government specifically for the general public’s safe exposure to 60 GHz and similar microwave radio systems. In addition to the very low power levels discussed above, 60 GHz systems do not even penetrate the human body! High-frequency emissions such as those from 60 GHz devices are absorbed by the moisture in the human body and are thereby prevented from penetrating beyond the outer layers of the skin. As a result, exposure to 60 GHz is very similar to the exposure to sunlight – but at around 1/10,000 of the typical sun's radiated energy at the earth's surface. Lower-frequency emissions penetrate and may even pass completely through the human body and are thus suspect. The minimal penetration of 60-GHz energy sets it far apart from the debate that currently surrounds the safety of other RF devices and communication systems. Several thousand same frequency (i.e. 60Ghz) systems can therefore safely be deployed in a ten-square kilometer area without ever worrying about interference or dangerous radiation.
All the very best, and keep up the good work, Guy ..
Jay Bowman
email: jaybowman@hushmail.com
