UWB - affect the stability of such existing systems ????? :(:(

Hi,
I wonder , Why do we have UWB ?
The reason for my above thought is due to the below lines- ,
" However first studies show that the rise of noise level by a number
of UWB transmitters puts a burden on existing communications
services.This may be hard to bear for traditional systems designs and
may affect the stability of such existing systems. "
Is it true that it will have a significant level of impact on the
existing systems ? Or, something wrong about it ? I wonder why is UWB
is supported if that is causing burden to existing communication
systems ? Any specific reason for continuation of support for it and
its survival ?

Thx in advans,
Karthik Balaguru

On Jan 19, 4:42*pm, karthikbalaguru <karthikbalagur...@gmail.com>
wrote:
> Hi,
> I wonder , Why do we have UWB ?
> The reason for my above thought is due to the below lines- ,
> " However first studies show that the rise of noise level by a number
> of UWB transmitters puts a burden on existing communications
> services.This may be hard to bear for traditional systems designs and
> may affect the stability of such existing systems. "
> Is it true that it will have a significant level of impact on the
> existing systems ? Or, something wrong about it ? I wonder why is UWB
> is supported if that is causing burden to existing communication
> systems ? Any specific reason for continuation of support for it and
> its survival ?
>

I find those lines in the below link -
http://en.wikipedia.org/wiki/Ultra-wideband

Karthik Balaguru

On Sat, 19 Jan 2008 03:42:24 -0800 (PST), karthikbalaguru
<(E-Mail Removed)> wrote:

>Hi,
>I wonder , Why do we have UWB ?
>The reason for my above thought is due to the below lines- ,
>" However first studies show that the rise of noise level by a number
>of UWB transmitters puts a burden on existing communications
>services.This may be hard to bear for traditional systems designs and
>may affect the stability of such existing systems. "
>Is it true that it will have a significant level of impact on the
>existing systems ? Or, something wrong about it ? I wonder why is UWB
>is supported if that is causing burden to existing communication
>systems ? Any specific reason for continuation of support for it and
>its survival ?
>
>Thx in advans,
>Karthik Balaguru

The signal bandwidth of a UWB system occupies channels used by other
systems. In order to do that and still meet regulations, it falls
under similar regulations as for unintentional emissions from any
electronics, like computers, toys, etc. The idea of the regulations
is to prevent too much radiated "pollution" from ruining the channels
for communications systems. The more radiation sources are present
the more pollutiing energy there is, but the sources tend to be spread
out enough that the sectra is still usable.

I think the same will be true of UWB devices, i.e., there won't be so
many of them that their energy will add up to anything significant,
especially since they transmit very low power levels, anyway.

So UWB devices try to sneak in on other device's channels but do so by
transmitting very low power levels. The Wiki article says not more
than -41.3dBm/MHz, which will be seen as a small increase in noise to
most systems, if noticed at all.

Eric Jacobsen
Minister of Algorithms
Abineau Communications
http://www.ericjacobsen.org

Eric Jacobsen wrote:

>On Sat, 19 Jan 2008 03:42:24 -0800 (PST), karthikbalaguru
><(E-Mail Removed)> wrote:
>
>
>
>>Hi,
>>I wonder , Why do we have UWB ?
>>The reason for my above thought is due to the below lines- ,
>>" However first studies show that the rise of noise level by a number
>>of UWB transmitters puts a burden on existing communications
>>services.This may be hard to bear for traditional systems designs and
>>may affect the stability of such existing systems. "
>>Is it true that it will have a significant level of impact on the
>>existing systems ? Or, something wrong about it ? I wonder why is UWB
>>is supported if that is causing burden to existing communication
>>systems ? Any specific reason for continuation of support for it and
>>its survival ?
>>
>>Thx in advans,
>>Karthik Balaguru
>>
>>
>
>The signal bandwidth of a UWB system occupies channels used by other
>systems. In order to do that and still meet regulations, it falls
>under similar regulations as for unintentional emissions from any
>electronics, like computers, toys, etc. The idea of the regulations
>is to prevent too much radiated "pollution" from ruining the channels
>for communications systems. The more radiation sources are present
>the more pollutiing energy there is, but the sources tend to be spread
>out enough that the sectra is still usable.
>
>I think the same will be true of UWB devices, i.e., there won't be so
>many of them that their energy will add up to anything significant,
>especially since they transmit very low power levels, anyway.
>
>So UWB devices try to sneak in on other device's channels but do so by
>transmitting very low power levels. The Wiki article says not more
>than -41.3dBm/MHz, which will be seen as a small increase in noise to
>most systems, if noticed at all.
>
>Eric Jacobsen
>Minister of Algorithms
>Abineau Communications
>http://www.ericjacobsen.org
>
>

UK CAA had (circa 2002) proposed banning inflight use of UWB radio
equipped laptops.

First in situ research done in 2007:
http://bul.ece.ubc.ca/James%20-%20UWB.pdf

Eric Jacobsen wrote:

> So UWB devices try to sneak in on other device's channels but do so by
> transmitting very low power levels. The Wiki article says not more
> than -41.3dBm/MHz, which will be seen as a small increase in noise to
> most systems, if noticed at all.
>
> Eric Jacobsen
> Minister of Algorithms
> Abineau Communications
> http://www.ericjacobsen.org
In the EU see Annex on page 4 for levels of max eirp densities:-

<http://eur-lex.europa.eu/LexUriServ/site/en/oj/2007/l_055/l_05520070223en00330036.pdf>
Since I live in the UK:-
Ofcom's consultation document 2005
<http://www.ofcom.org.uk/consult/condocs/uwb/uwb2/uwb.pdf>
Since they have more or less had to comply with the EU directive
<http://www.ofcom.org.uk/consult/condocs/uwb_exemption/statement/statement.pdf>