WiFi Bad For Your Health

[pilgrim]

The reason people have issues with wireless is simply that their expectations have been overset by marketing hype, and a very ill-informed press.

Wifi was - and still is - a technology designed to provide line-of-sight communications over a distance of 100m. In real-world terms, that means either LAN bridging or LAN extension.

An example of LAN bridging is a wireless bridge between two neighbouring sites, such as adjacent buldings seperated by a road where it is impossible to provide an ethernet link.

LAN extension is extending the nodal reach of an ethernet segement - analogous to putting more LAN sockets in a room. Instead of sockets, one installs an Access Point connected to the LAN, and voila, there is an area of wireless connectivity. Its the same as having a laptop on a long LAN cable and running on batteris.

Media hype of course presents wireless as a complete replacement technology for the traditional wired LAN. This is rubbish. Read the first statement - line-of-sight. The walls and floors between rooms in one's house negate this basic tenent. Yes, it can work, but then my cabrio can also drive cross-country. Sort of. Not very well.

Why line-of-sight? Because RF radiation is hampered by walls (even sheets of wet paper can prevent signal propogation), and solid objects tend to cause wave refraction; the signal bounces all over the place. And remembering back to basic secondary school physics, when waves colliding affect the wave;

peaks and peaks combine, casuing a stronger wave (for the period the peaks are in phase)
peaks and troughs cancel each other out
troughs and troughs combine forming a deep trough

Not a good scenario. The upshot is, the signal propogation is compromised, leading to poor data throughput.

To effectively install a wireless LAN, one needs to do a whole lot more than add a wireless router or AP; site survey, security (do you really want every device on a network visible to *everyone* if you saturate a site with a dozen APs in multi-point mode?), channel planning, and so on.

No, the best usage is to retain a traditional wired backbone (ethernet switch), run cabling to the rooms, and then install APs where necessary.

Quite apart that 100mbit ethernet will outperform even 802.11n (when it gets ratified) for a while to come yet. Why? You don't get 540mbit, or 320mbit, throughput :-) Go read the standards, and the theory of operation. Didn't the marketing droids say that.. I wonder why :-)

[maiko03]

This is really interesting to me and just makes me think twice cause I'm almost always in the presence of wireless. Anyways everyone gave some great points.

[pilgrim]

Something closer to the point of the original post:

Parents and scientists (or is that sciencetits) are concerned over the levels of electromagnetic radiation from wireless devices, are they?

I wonder how many of these concerned parents have cordless phones, DECT devices, and microwave ovens in their houses... because they all operate in the 2.4GHz spectrum, the same as 802.11x wireless equipment. And what's more, they operate at higher power levels. The typical AP pumps out a few watts of power on a 2BDi antenna. A microwave oven pumps out between 650W and 800W...

Oh roll on the proposed opening up - and unlicensing - of the 100GHz+ spectrum for "personal communication devices" in the UK. We'll know within two generations what effect it has when our grandchildren are two headed window-lickers :-)

[BiG K]

Originally Posted by pilgrim

Oh roll on the proposed opening up - and unlicensing - of the 100GHz+ spectrum for "personal communication devices" in the UK. We'll know within two generations what effect it has when our grandchildren are two headed window-lickers :-)

Not all wavelengths are dangerous for us, although 100Ghz ociliates a little fast lol Just specific one's. Only problem is, we have absolutely no idea which wavelengths are harmful for us and which arent!

For example if our brains operate at 8Ghz and we are broadcasting a signal at 8Ghz, then there is the potential for something going seriously wrong!

[leexgx]

wifi is about 50% more powerfull then hands free kits for phones thay are power out put in mW not watts

my mobile phone has an range of 2km my wireless at best 20-30m indoors 50m out doors my hands free 10m range ish

and the 100ghz stuff will have range on about 1m-0.5m line of site its for replaceing the HDMI cable so we can use HD wireless (behind the tv tho range of 1m-0.5m the power out put be Less then what Bluetooth headsets put out by alot)

its like when the wireless 5Ghz came out it was rubbish as the power was 50% less then 802b/g so it could not even get tho most walls and ended up faling back to 802b/g mode so that product died fast (i only seen netgear sell it)

i be more intrested in mobile phones as thay kick out alot more power