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Thread: Is there a Bluetooth PCI card that is *just* bluetooth (and not combowifi) ?

  1. #21
    Sum Guy
    Guest

    Re: Is there a Bluetooth PCI card that is *just* bluetooth (and notcombo wifi) ?

    Jeff Liebermann wrote:

    > > You should probably read more recent posts in a thread before
    > > responding to an early post.

    >
    > I should, but I'm lazy. I'll just write some more, and maybe
    > later see how close I guessed.


    Then I'll wait until you read the rest of the older posts in this
    thread.

  2. #22
    Jeff Liebermann
    Guest

    Re: Is there a Bluetooth PCI card that is *just* bluetooth (and not combo wifi) ?

    On Sat, 06 Jun 2009 09:07:21 -0400, Sum Guy <Sum@Guy.com> wrote:

    >Tell me who's dreaming:


    Whomever doesn't do the math.

    >http://longrangebluetooth.net/
    >
    >The AIRcable Host XR, equipped with an extremely-powerful,
    >highly-sensitive Bluetooth transmitter, can achieve an unparalleled
    >range of up to 30 km! With a 9 dBi omni-directional antenna, the
    >extended range is up to 2 km, and with the 18 dBi directional antenna,
    >it is up to 10 km.


    The data sheet claims that with the stock antennas, the range is 1km.
    The antennas look to be fairly typical 2dBi coaxial antennas. Range
    doubles for every 6dB increase in antenna gain. That data sheet
    claims 1km range with the stock antennas.

    Range doubles for every 6dB of gain (inverse square law) or:
    dB = 20 log (range_ratio)
    or
    range_ratio = 10^(gain_in_dB/20)
    Building a table:

    Antenna Claimed range gain dB over range calc km
    gain km 2dBi omni increase range
    2dBi omni 1 0 0x 1
    9dBi omni 2 7 2.2x 2.2
    18dbi dir 10 16 6.3x 6.3

    So, the doubling of the range using the 9dBi omni is probably for
    real, but the 10km range is a bit optimistic. Of course, all this
    depends on the original data sheet 1km specified range. There are
    plenty of other variables, such as the performance of the device at
    the other end of the link. If it's a Class 2 (10mw) device, there's
    not going to enough signal coming back to create a useful link. The
    TX power has to be the same in both directions for this to work. Same
    with the receiver sensitivity. Any asymmetry will result in range
    loss. It's highly likely that the receiver in the AIRCable device has
    been dramatically improved over the usual minimal designs found in
    most commodity BT devices. If so, then the increased RX sensitivity
    in the AirCable device may somewhat compensate for the lack of TX
    power in the GPS BT device. However, it's difficult to tell without
    the maker and model number of the GPS device and associated
    specifications.

    >The AIRcable Host XR's Bluetooth radio receiver is many times more
    >sensitive than the average Bluetooth device. You can expect about a 10
    >times more range than with other standard Bluetooth dongles.


    Yep. A better receiver. -92dBm sensitivity (presumably at 0.1% BER).
    Minimum spec is -70dBm so this is far better than usual. The reason
    they get away with it is that they don't have any serious power
    consumption limitations and they don't have a mess of RFI and noise
    belching devices nearby such as inside a cell phone. Increase the
    sensitivity to practical BT limits and all the typical BT device will
    pickup is noise and junk.

    Kinda looks like it will do what you want. I'm not so confident about
    the range increase, but with a big antenna, you will certainly get an
    improvement.

    Incidentally, I lied. There are chips that can do simultaneous BT and
    Wi-Fi. See:
    <http://focus.ti.com/general/docs/wtbu/wtbuproductcontent.tsp?templateId=6123&navigationId=12027&contentId=4655>
    It was product released 2 months ago, so there may not be any products
    available for a while. It also targets multi-media cell phone
    handsets, not laptops.

    Full disclosure: I did some very very very minor work for Wireless
    Cables when they were in Santa Cruz CA. Good people.

    --
    Jeff Liebermann jeffl@cruzio.com
    150 Felker St #D http://www.LearnByDestroying.com
    Santa Cruz CA 95060 http://802.11junk.com
    Skype: JeffLiebermann AE6KS 831-336-2558

  3. #23
    Jeff Liebermann
    Guest

    Re: Is there a Bluetooth PCI card that is *just* bluetooth (and not combo wifi) ?

    On Sun, 07 Jun 2009 15:20:48 -0400, Sum Guy <Sum@Guy.com> wrote:

    >Jeff Liebermann wrote:
    >
    >> > You should probably read more recent posts in a thread before
    >> > responding to an early post.

    >>
    >> I should, but I'm lazy. I'll just write some more, and maybe
    >> later see how close I guessed.

    >
    >Then I'll wait until you read the rest of the older posts in this
    >thread.


    Ok, I've read the rest of the thread and commented on one item of
    interest. Enlightenment will surely follow.

    Ignoring the PCI and ancient Windoze diversions, what you're really
    trying to do is get some real range out of a GPS receiver. There are
    easier ways. Most GPS receivers have a 4800 baud serial output that
    belches NMEA 183 protocol data. Wireless serial devices are very
    common. I use a mix of 900MHz and 2.4GHz boards by MaxStream, Digi
    International, and FreeWave for the purpose. Serial in and serial out
    with the added bonus of multipoint for building a network. I have one
    data link that sends DGPS (differential GPS) RTCM-SC104 codes for high
    accuracy robotic navigation. If your unspecified model USB GPS
    doesn't have an available 4800 baud serial output (usually TTL, not
    RS-232), then it might be easier to just buy one that does.
    Unfortantely, a new GPS plus 2 radios will be far more expensive than
    the Wireless Cables solution. (I cheated as we obtained a large pile
    of radios and GPS boards for next to nothing).

    Hmmm... checking the range, one 900MHz data link is about 8km (5
    miles) and another is about 3km (2 miles) through a wall of dense
    forest. The links actually run at 57.6kbit/sec and have weather and
    telemetry data muxed in with the GPS corrections.

    --
    Jeff Liebermann jeffl@cruzio.com
    150 Felker St #D http://www.LearnByDestroying.com
    Santa Cruz CA 95060 http://802.11junk.com
    Skype: JeffLiebermann AE6KS 831-336-2558

  4. #24
    Jeff Liebermann
    Guest

    Re: Is there a Bluetooth PCI card that is *just* bluetooth (and not combo wifi) ?

    On Sun, 07 Jun 2009 13:43:40 -0700, Jeff Liebermann <jeffl@cruzio.com>
    wrote:

    >>http://longrangebluetooth.net/
    >>
    >>The AIRcable Host XR, equipped with an extremely-powerful,


    FCC ID: SQC ACC1600
    Plug that into:
    <http://www.fcc.gov/oet/ea/fccid/>

    --
    Jeff Liebermann jeffl@cruzio.com
    150 Felker St #D http://www.LearnByDestroying.com
    Santa Cruz CA 95060 http://802.11junk.com
    Skype: JeffLiebermann AE6KS 831-336-2558

  5. #25
    Sum Guy
    Guest

    Re: Is there a Bluetooth PCI card that is *just* bluetooth (and notcombo wifi) ?

    Jeff Liebermann wrote:

    > If your unspecified model USB GPS doesn't have an available 4800
    > baud serial output (usually TTL, not RS-232), then it might be
    > easier to just buy one that does.


    I am thinking of experimenting with seeing how far I can communcate with
    a small bluetooth-enabled GPS logger (Photomate, model 887). Hence my
    desire for bluetooth hardware with excellent transmit and receive
    capability, the ability to connect an external antenna, etc.

    I thought my only credible option was a PCI card (where size constraints
    would not limit the circuit design of the radio portion) and where an
    external antenna connection is assured.

    An outboard box (not a dongle) connected via USB also fits that
    description.

  6. #26
    alexd
    Guest

    Re: Is there a Bluetooth PCI card that is *just* bluetooth (and not combo wifi) ?

    Sum Guy wrote:

    > So you are <snip intricate description of a man made of straw>


    No. I'm saying you shouldn't expect miracles out of a new dongle + antenna.
    Take my advice it or leave it [I think I can guess which you'll do].

    --
    <http://ale.cx/> (AIM:troffasky) (UnSoEsNpEaTm@ale.cx)
    21:38:26 up 33 days, 2:08, 1 user, load average: 0.41, 0.28, 0.17
    A few flakes working together can unleash an avalanche of destruction



  7. #27
    Sum Guy
    Guest

    Re: Is there a Bluetooth PCI card that is *just* bluetooth (and notcombo wifi) ?

    alexd wrote:

    > No. I'm saying you shouldn't expect miracles out of a new dongle
    > + antenna. Take my advice it or leave it [I think I can guess
    > which you'll do].


    What the hell bug crawled up your ass and died?

    Why are you getting so bent out of shape at the concept that maybe, just
    maybe, it just might be possible to build a bluetooth transceiver with
    significantly more range than a puney thumb-nail-sized usb stub if
    you're not limited to a device envelope the size of a puney
    thumb-nale-sized usb stub?

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