I am looking for a home audio solution.  I need to play MP3 music from
my Laptop on my Home Theater.  I need to do this over Bluetooth, ie. 
I don't need any wired solution.  My laptop or my Home theater does
not have Bluetooth capabilities.  But my laptop has USB ports.  I am
aware of USB dongles for Bluetooth.  My Laptop runs windows based
operating system.  In the answer I would like to have the following
details,

-Is this feasible ?
-If feasible are there any commercial solutions available?
-If feasible and no commercial solutions are available, what is your
idea about building such a solution?
-What are the possible alternatives, 

One schematic that I have in mind is an USB dongle with correct audio
device drivers communicating with a Power plugged Bluetooth receiver
connected to the audio input using RCA / Mini Jack connectors.
-If you are discussing any no-existent commercial products, are there
any related technology licensing issues that you know.

bonigv-ga,

Thank you for your question, I hope that you find the following answer
useful.

Summary:
--------

Wireless audio streaming solutions are commercially available from
several manufacturers, including Linksys. These solutions use the
802.11 wireless standard instead of the Bluetooth standard, due to the
range and data-rate limitations of Bluetooth. With the 802.11
solutions, you can easily play your MP3 files through your home
theater.


Details:
--------

The Bluetooth standard supports a recommended maximum range of 10
meters, due to the 1 milliwatt transmission strength defined by the
standard. The maximum data-rate possible in one direction is 721 kbps,
assuming that there is no interference. Bluetooth operates in the
unlicensed 2.45 GHz frequency spectrum, using spread-spectrum
technology to reduce the impact of interference.

Because of this data-rate and limited range, the manufacturers of
specialized streaming audio solutions have chosen not to go with
Bluetooth. The intent for the manufacturers is to maximize the
potential market while minimizing the support costs, so by choosing
802.11b and 802.11g as the wireless standard, they can take advantage
of data-rates from 11 Mbps to 54 Mbps, and usable ranges from 150 feet
to 1000 feet. 802.11b and g also operate in the 2.4 GHz band, but use
discrete "channels".

The specialized solutions that they have come up with are represented
by a device such as the Linksys Wireless-B Media Adapter. This device
connects to your home theater using standard RCA cables (stereo audio
and video or S-video). You will also need an 802.11b wireless network
adapter such as the Linksys Wireless-B Notebook Adapter (WPC11) or USB
adapter (either Linksys WUSB11 or WUSB12). Then, after installing a
utility on your laptop, you can use the Media Adapter to remotely
search through and play any MP3 file you have on the notebook
computer. You can also use the Media Adapter to display any pictures
that you have on the notebook, if you have a TV connected to the Media
Adapter.

Since you state that you do not already have any Bluetooth devices,
this makes an 802.11b-based solution even more viable. 802.11b
networking devices are more readily available these days versus
Bluetooth networking devices. Bluetooth is, more and more, being used
only for "personal area networking" solutions such as mobile phone
headsets, PDA synchronization, and simple computer communications.

The Linksys equipment mentioned above can be found at:

Media Adapter (WMA11B):

http://www.linksys.com/products/product.asp?grid=33&scid=36&prid=554

Notebook Adapter (WPC11):

http://www.linksys.com/products/product.asp?grid=33&scid=36&prid=542

USB Adapter (WUSB11):

http://www.linksys.com/products/product.asp?grid=33&scid=36&prid=435

USB Adapter (WUSB12):

http://www.linksys.com/products/product.asp?grid=33&scid=36&prid=519


Additional Links:
-----------------

"How Bluetooth Works"

http://www.howstuffworks.com/bluetooth.htm


"Wi-Fi Expands Home Networking"

http://www.wirelessweek.com/index.asp?layout=article&articleid=CA276962


-----------------


I hope that you find this information useful; please let me know if
you require any clarification to this answer.

Regards,

aht-ga

---

Request for Answer Clarification by bonigv-ga on 18 Aug 2003 18:57 PDT

Thank you for your answer.  I must say it was of no use to me.  I am
sorry.
My question is specifically to do with Bluetooth.  I do not think your
answer helps me.  Can you please suggest a solution with Bluetooth.

---

Clarification of Answer by aht-ga on 18 Aug 2003 20:01 PDT

My apologies, as you had mentioned that neither your laptop nor your
home theater was already equipped with Bluetooth capabilities, I
presumed to provide you with the easiest commercially available
solution instead of restricting my answer to just Bluetooth solutions.

To address your question(s) in the order you asked them:

--------
- Is this feasible: 

Yes, it is feasible (but not advisable) to use Bluetooth to stream
audio from a PC to a home theater system, with the understanding that
there will be quality issues


--------
- If feasible are there any commercial solutions available:

Here are the commercially available Bluetooth solutions. Note that,
depending where in the world you are located, they may or may not be
commercially available to you.

Fujitsu has a limited-sale device called the AIRJUKE, which is only
available to customers of their PCs, in Japan:

http://pcworld.shopping.yahoo.com/yahoo/article/0,aid,106136,00.asp


You most likely are already aware of the USB Bluetooth adapters, such
as the D-Link DBT-120:

http://www.dlink.com/products/?pid=34


Last year, a Bluetooth developer, Impulsesoft, released a reference
design for a Bluetooth Wireless Stereo Adapter:

http://www.impulsesoft.com

Unfortunately, to date no manufacturer has used this design in a
commercially available product.


--------
- If feasible and no commerical solutions are available, what is your
idea about building such a solution:

The simplest way to create such a solution yourself, without requiring
electronics development work, is to find a low-cost computer that can
be dedicated to the home theater system, equip it with a Bluetooth
adapter, a stereo sound card, and an MP3 player application, and use
it in a wireless Bluetooth network with your laptop to access and play
the MP3 files stored on your laptop. Any other solution would require
the development of custom firmware and custom electronics for the
Bluetooth-enabled receiver at the home theater end of the connection.
If you are an electronics expert, then you can consider using the
Impulsesoft reference design (they may be willing to sell you a
development kit) along with a basic power and amplifier circuit to
build your own, dedicated device; however, the expense of doing so
would outweigh the cost of buying a low-cost computer with sound and
Bluetooth capabilities. The main part of the expense would be the
licensing expenses related to obtaining the Impulsesoft design.


--------
- What are the possible alternatives:

I reiterate that the best option for streaming audio from a PC to a
home theater, is to use a commercially available Wi-Fi device such as
described in my original answer above. Another viable alternative is
the USB FM transmitter mentioned in snsh-ga's comment below, however
the audio quality will suffer from the conversion to FM.

The Bluetooth protocol is a data protocol, so any Bluetooth solution
will require data-capable devices at both ends. If you are not able to
find a Fujitsu AIRJUKE device available for re-sale, then I strongly
urge you to consider using a Wi-Fi solution for the situation you
described above. If there is a specific reason why the solution must
be Bluetooth, then your options are quite limited.

If this clarification still does not meet your needs, please let me
know exactly why you need a Bluetooth solution so that I can better
understand the context that you need the answer to relate to.

Regards,

aht-ga

Hi aht-ga,

You have given me very meaningful directions.  Thanks a lot.  

regards
Boni Gopalan

USB FM transmitters are a bit simpler than audio over wifi.
You plug it in your USB, tune the radio to 88.something, and listen.
You lose reponse >14kHz with FM, though.

If you go the wireless route, this story about one man's experience is
fairly entertaining:
http://slate.msn.com/id/2079190/

snsh-ga,

Your suggestion was a totally new way to look at the problem.  May be
it will work for certain scenarios too.  Do you know any commercially
available products fpr this. Also the article you pointed on wi-fi was
informative.  On the FM-USB route does it have any limitations on the
quality of sound?, I do not think there is a vast deterioration in
music quality over FM transmission.  But ofciurse I am not the best
person to comment on that.

Thank you
Boni Gopalan.

I only have secondhand experience, sorry.  But the people I know who
use it firsthand seem satisfied with it and like to show it off.

Search ebay for "USB FM transmitter" and lots of options present
themselves.  Some are higher power than others -- farther range.

The deterioration with FM is just the 14-15kHz cutoff, and is inherent
to the 0.1MHz spacing between FM stations.  It's possible that some
USB transmitters send the higher frequency sounds anyway, but your
stereo still might cut them out.  Myself, I grew up listening to
radio, so having that high-frequency cutoff actually makes music sound
"better" to me anyway.  What you think sounds "best" has a lot to do
with the stereos you are accustomed to listening to.