specific absorption rate

[Robin Paulson]

i was looking through planet earlier, when i saw this blogpost, which
i'm sure others of you have read:

http://blogs.thehumanjourney.net/finds/entry/20080901

i gather it's a report on the effects of emitted radiation when the
freerunner is used near to a person's body. is there anyone here who
understands these things. would it be possible to explain what this
means, in a more condensed terms and understandable way?

i'm not looking for 'The Idiot's Guide to Mobile Phone Radiation', or
anything like that, but something a bit simpler to understand. I'm
sure there are others here who would be interested to here this too

thanks

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[Minh Ha Duong]

> i was looking through planet earlier, when i saw this blogpost, which
> i'm sure others of you have read:
>
> http://blogs.thehumanjourney.net/finds/entry/20080901

The Neo FreeRunner SAR tests at 1.07 W/kg GSM and 1.17 W/kg DCS. I would
say that's average, on the high side.

The legal limit 1.6 W/kg in the US, 2 W/kg in the EU, and really few on
the market get below 0.3.

I guess that having a setting to limit the radiations emissions at the
expense of radio sensitivity would be a Good Thing. Open Source choice is
better for your health. That's has a different convincing power than `you
can choose whichever keyboard you like', yes ?

Minh

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[roguemoko]

On Tuesday 02 September 2008 15:51:00 Robin Paulson wrote:

> i was looking through planet earlier, when i saw this blogpost, which
> i'm sure others of you have read:
>
> http://blogs.thehumanjourney.net/finds/entry/20080901
>
> i gather it's a report on the effects of emitted radiation when the
> freerunner is used near to a person's body. is there anyone here who
> understands these things. would it be possible to explain what this
> means, in a more condensed terms and understandable way?
>
> i'm not looking for 'The Idiot's Guide to Mobile Phone Radiation', or
> anything like that, but something a bit simpler to understand. I'm
> sure there are others here who would be interested to here this too

I don't know the specifics now but I looked into it years ago. The end result
was that any mobile with an internal antenna is more damaging to human cells
than one with an external antenna. The theory being that the transmission is
taking place further away from your body.

The only use I can see for the findings is to compare existing antenna models
to pick the lowest value.

From memory the motorola startac, like 7 years after it's release, was still
the lowest. Ericsson tended to have the higher values with nokia falling
somewhere in between.

The way I see it is, there is a required/acceptable amount of power required
to reach the nearest tower. Anything lower would be unacceptable and the
findings then fall on the antenna design.

Currently nearly all phones omit an antenna and therefore increase the SAR
(and decrease the signal quality). I admit, I've never understood why an
antenna like the startac's han't been included in newer phones. It did retract
after all. The alternative these days is to use a headset/ear piece (and
probably leave the phone near other important parts of you body!).

The overall effect is that nearly all current mobile phones have a similar
SAR, as far as I can tell anyway (give or take, usually based on the design of
the internal antenna).

It's been a while so thing may have changed ...

Sarton

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[Jörgen Lidholm]

Hello guys.
I just read a list of cell phones and their radiation levels.

The worst phones were:
Modell: SAR
Sony Ericsson T650 1,80
Sony Ericsson W880 1,45
Sony Ericsson Z1010 1,41
Sony Ericsson W950 1,35
Motorola SLVR L6 1,33

The best models were:
Modell: SAR
LG Chocolate KG800 0,12
Samsung SGH-X830 0,12
Motorola MPx200 0,12
LG KG245 0,12
LG KG320S 0,13

These values are from a Swedish magazine.

Regards,
        Jörgen Lidholm

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> [hidden email]] För [hidden email]
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> Till: List for Openmoko community discussion
> Ämne: Re: specific absorption rate
>
> > i was looking through planet earlier, when i saw this blogpost, which
> > i'm sure others of you have read:
> >
> > http://blogs.thehumanjourney.net/finds/entry/20080901
>
> The Neo FreeRunner SAR tests at 1.07 W/kg GSM and 1.17 W/kg DCS. I would
> say that's average, on the high side.
>
> The legal limit 1.6 W/kg in the US, 2 W/kg in the EU, and really few on
> the market get below 0.3.
>
> I guess that having a setting to limit the radiations emissions at the
> expense of radio sensitivity would be a Good Thing. Open Source choice is
> better for your health. That's has a different convincing power than `you
> can choose whichever keyboard you like', yes ?
>
> Minh
>
> _______________________________________________
> Openmoko community mailing list
> [hidden email]
> http://lists.openmoko.org/mailman/listinfo/community,

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[Robin Paulson]

2008/9/2 Sarton O'Brien <[hidden email]>:

> I don't know the specifics now but I looked into it years ago. The end result
> was that any mobile with an internal antenna is more damaging to human cells
> than one with an external antenna. The theory being that the transmission is
> taking place further away from your body.
>
> The only use I can see for the findings is to compare existing antenna models
> to pick the lowest value.
>
> From memory the motorola startac, like 7 years after it's release, was still
> the lowest. Ericsson tended to have the higher values with nokia falling
> somewhere in between.
>
> The way I see it is, there is a required/acceptable amount of power required
> to reach the nearest tower. Anything lower would be unacceptable and the
> findings then fall on the antenna design.

is the relationship as simple as:
increase the antenna size, decrease the radiation?
could an external antenna help increase battery life also?

is this something we can choose ourselves, or are there particular
requirements we should be aware of?

> Currently nearly all phones omit an antenna and therefore increase the SAR
> (and decrease the signal quality). I admit, I've never understood why an
> antenna like the startac's han't been included in newer phones. It did retract

the public values compactness over safety?

> after all. The alternative these days is to use a headset/ear piece (and
> probably leave the phone near other important parts of you body!).

someone suggested this was a bad idea, cos you're plugging the antenna
straight into the side of your head, actually making things worse

> The overall effect is that nearly all current mobile phones have a similar
> SAR, as far as I can tell anyway (give or take, usually based on the design of
> the internal antenna).
>
> It's been a while so thing may have changed ...

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[Robin Paulson]

2008/9/2 Robin Paulson <[hidden email]>:
> is the relationship as simple as:
> increase the antenna size, decrease the radiation?
> could an external antenna help increase battery life also?
>
> is this something we can choose ourselves, or are there particular
> requirements we should be aware of?


http://wiki.openmoko.org/wiki/External_GSM_Antenna

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[roguemoko]

On Tuesday 02 September 2008 17:56:26 Robin Paulson wrote:
> 2008/9/2 Sarton O'Brien <[hidden email]>:
> > The way I see it is, there is a required/acceptable amount of power
> > required to reach the nearest tower. Anything lower would be unacceptable
> > and the findings then fall on the antenna design.
>
> is the relationship as simple as:
> increase the antenna size, decrease the radiation?

From what I understand, the SAR is determined under normal operation. If less
of the transmission is occurring close to your body, then the SAR decreases.

So I guess ... the answer is probably yes.

> could an external antenna help increase battery life also?

If you were able to decrease the sensitivity then I'd say that's a
possibility.

> is this something we can choose ourselves, or are there particular
> requirements we should be aware of?

That I have no idea about and would depend on what I said above.

> > Currently nearly all phones omit an antenna and therefore increase the
> > SAR (and decrease the signal quality). I admit, I've never understood why
> > an antenna like the startac's han't been included in newer phones. It did
> > retract
>
> the public values compactness over safety?

Since when has the human race as a whole been smart? We learn quickly compared
to other species but way too slow for our own good.

> > after all. The alternative these days is to use a headset/ear piece (and
> > probably leave the phone near other important parts of you body!).
>
> someone suggested this was a bad idea, cos you're plugging the antenna
> straight into the side of your head, actually making things worse

That assumes the ear piece is the antenna. Not always the case. In the case of
the FR, I don't know if this is the case or not.

> > The overall effect is that nearly all current mobile phones have a
> > similar SAR, as far as I can tell anyway (give or take, usually based on
> > the design of the internal antenna).
> >
> > It's been a while so thing may have changed ...

To be honest, I gave up caring.

Sarton

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[Cédric Berger]

On Wed, Sep 3, 2008 at 01:20, Sarton O'Brien <[hidden email]> wrote:
>
> That assumes the ear piece is the antenna. Not always the case. In the case of
> the FR, I don't know if this is the case or not.

the GSM antenna for the Neo is at the bottom (under the mic, not the speaker).
So it is a little less close to your head. And it must also have been
taken in account in SAR values -radiations are measured in normal
operations, phone put near the head-

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[Joseph Reeves]

You can see in the test pics - they hold the bottom of the phone away
from the jaw - just like in actual use. You'd expect lower results
from a phone with the antenna down there; the FreeRunner must really
kick out some juice ;)



2008/9/3 Cédric Berger <[hidden email]>:

> On Wed, Sep 3, 2008 at 01:20, Sarton O'Brien <[hidden email]> wrote:
>>
>> That assumes the ear piece is the antenna. Not always the case. In the case of
>> the FR, I don't know if this is the case or not.
>
> the GSM antenna for the Neo is at the bottom (under the mic, not the speaker).
> So it is a little less close to your head. And it must also have been
> taken in account in SAR values -radiations are measured in normal
> operations, phone put near the head-
>
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[roguemoko]

Cédric Berger wrote:

> On Wed, Sep 3, 2008 at 01:20, Sarton O'Brien <[hidden email]> wrote:
>  
>> That assumes the ear piece is the antenna. Not always the case. In the case of
>> the FR, I don't know if this is the case or not.
>>    
>
> the GSM antenna for the Neo is at the bottom (under the mic, not the speaker).
> So it is a little less close to your head. And it must also have been
> taken in account in SAR values -radiations are measured in normal
> operations, phone put near the head-
>  

Yes, my understanding is that a headset has always been the primary way
to reduce exposure. The only time I've heard of a headset acting as an
antenna is with an am/fm radio.

I was mainly pointing out that I don't know if the FR or any mobile
in-fact would use the headset as an antenna. I doubt it.

Sarton

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[roguemoko]

Joseph Reeves wrote:
> You can see in the test pics - they hold the bottom of the phone away
> from the jaw - just like in actual use. You'd expect lower results
> from a phone with the antenna down there; the FreeRunner must really
> kick out some juice ;)
>  

Maybe this accounts for the clicking in my jaw of late ;)


I don't think it really matters about placement, although, further from
your brain is always helpful!

Sarton

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