Pompano Beach, FL
Cell phone tech is another risk factor..
Considering that modern Cell phones operate near the frequency of uWave ovens, and the owners are placing the antennas next to their heads it would be prudent to limit your exposure.
Use a bluetooth headset or use the speaker phone setting. Get some distance between the antenna and your head. or just send a text message.
B.T.W. A number of insurance co's now consider cell phone manufacturers to be Uninsurable Risks.
Note: A number of the older studies are flawed, since all cell phone tech is variable output, and frequencies are now much higher, (where the FCC allows 10x more energy/kg).
u is not Î¼. If you're going to try and sound all technical, at least get it right.
EDIT - that was supposed to be a mu obviously, apparently DSLReports doesn't handle Unicode in the posts! -
I don't know what you mean by the frequencies are now much higher and the FCC allowing more energy. The FCC allows 1.6 W/kg averaged over 1g. That hasn't changed, and applies to all bands used.
Yes, the output is variable. The peak is 200mW on most tech, but it never gets there. I'm in a LOW signal area (not a good area) and right now my phone's transmit power is -2dBm. That's 0.63mW! To be fair, that's extremely low, but it rarely breaks 5-10dBm. A tiny fraction of the 13-20dBm most laptops output as a constant power for Wi-Fi. Also, a tiny fraction of most home cordless phones.
The peak amount (when you're furthest from the cell site) is higher, but normally, UMTS mobile phones operate at much LOWER power levels than short-range technologies people see as much safer. I find it hilarious. Why is this? UMTS operates down to extremely low received power levels (potentially as low as -113dBm) and every call has to come in to the cell site at the SAME power level, so every phone is constantly being told to adjust power.
On the other hand, with Wi-Fi, home cordless, etc, you want the received power to be as high as possible. Wi-Fi needs at least -96dBm in theory, and in the real world at least -80dBm for good performance. That's many orders of magnitude higher than the received power level the cell phone network is aiming for.
Pompano Beach, FL
Unless you eye's on the side of your head.. (or a decent screen capture program, that can do a timed series of snapshots)..
You have no idea what the real cell phone xmit power will be while the phone is in use. Weaker signal reception, (fewer bars), will likely occur when phone is placed next to head(or body), and that will boost cell phone xmit power significantly.
For example "iphone 3gs prod info guide" "When carrying iPhone, keep it 1.5 cm (5/8 inch) or more away from your body to ensure exposure levels remain at or below the maximum levels. Avoid cases with metal parts."
Now Just how many people kept their Iphone over 1/2" from head when talking on them??
That's for body-worn exposure, and it may comply closer but it's not tested, they do test head exposure touching your ear. Also remember exposure levels are tested on WORST-CASE (furthest from the cell site you can be and still barely hold a call basically) exposure. I'd feel totally safe at ten times the maximum exposure level anyways, it's all insanely low. But modern (UMTS or CDMA) cell phones are one of the lowest exposure radio devices in existence. Not because they want to keep your exposure down but because they want better battery life in smaller devices. That means designing very sensitive receivers, and making the system work down to absurdly low power levels. If cell phone networks needed the received power level Wi-Fi needs, we'd be carrying around bricks to talk on...
In the beginning
In the early days there used to be results of cell phone studies posted on the internet. I should have downloaded the early Motorola report that said they thought they might toast your eye balls. They decided to run at low power to get around the problem. In other words, it will just take longer to go blind with the lower power.
Remember the 5 watt CB burns? You were cooked to the bone---then you felt it.
No, it's NOT a case of a cumulative effect. Heat dissipates. Being in a warm room doesn't mean you'll just get third degree burns slower than if you fall in a bonfire! Your corneas won't get burnt if the power is low enough to dissipate and keep them in a safe range! It's all just HEAT that is the concern.
5 watts is not the same as 200mW (peak, with real world powers usually well under 50mW). Early mobile phones went up to 3 watts. Making a handheld version of that could cause some serious heating concerns, especially eye damage, yes. Also, terrible battery life.