[J2ME and Bluetooth] Trying to connect 3 mobile phones

Discussion in 'Java' started by Michael Sars Norum, Mar 1, 2005.

  1. Hi

    I'm currently working on a research project where we are developing a
    framework for ad hoc network based application on J2ME using Bluetooth
    as a reference implementation in the network layer.

    We currently have code running that connects to phones and allows them
    to communicate. However we have problems connecting three phones in a
    network.

    So far we have found that device discovery can not be done in parallel
    on the phones. Does this mean that we can not connect a phone to more
    than a single device at a time?

    We are currently using the RFCOMM protocal for communication, does this
    force any added restrictions as to how many connections can be open at
    once? The Bluetooth spec states that a Bluetooth piconet can consist of
    up to 8 devices (one master and 7 slaves). Do mobile phones not
    implement this or is it possibly just a limitation in JABWT?

    We are currently using 3 phones for testing, SE p900, Nokia 6600 and
    Siemens S65. All three phones have different behaviour as to how they
    handle different events. And the SE p900 actually have an erroneous
    JABWT implementation.

    All answers are highly apreciated,
    Regards
    Michael Sars Norum
    Ps. Our project website is http://www.peer2me.org
    Michael Sars Norum, Mar 1, 2005
    #1
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  2. Michael Sars Norum wrote:
    > I'm currently working on a research project where we are developing a
    > framework for ad hoc network based application on J2ME using Bluetooth
    > as a reference implementation in the network layer.
    >
    > We currently have code running that connects to phones and allows them
    > to communicate. However we have problems connecting three phones in a
    > network.
    >
    > So far we have found that device discovery can not be done in parallel
    > on the phones. Does this mean that we can not connect a phone to more
    > than a single device at a time?


    It's my understanding of Bluetooth that you can only connect to one
    remote system in the piconet using the radio itself, even though it can
    discover multiple devices.

    --
    Darryl L. Pierce <>
    Visit my homepage: http://mcpierce.multiply.com
    "By doubting we come to inquiry, through inquiry truth." - Peter Abelard
    Darryl Pierce, Mar 1, 2005
    #2
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  3. Michael Sars Norum

    JScoobyCed Guest

    Michael Sars Norum wrote:
    > Hi
    >
    > I'm currently working on a research project where we are developing a
    > framework for ad hoc network based application on J2ME using Bluetooth
    > as a reference implementation in the network layer.
    >
    > We currently have code running that connects to phones and allows them
    > to communicate. However we have problems connecting three phones in a
    > network.
    >
    > So far we have found that device discovery can not be done in parallel
    > on the phones. Does this mean that we can not connect a phone to more
    > than a single device at a time?
    >
    > We are currently using the RFCOMM protocal for communication, does this
    > force any added restrictions as to how many connections can be open at
    > once? The Bluetooth spec states that a Bluetooth piconet can consist of
    > up to 8 devices (one master and 7 slaves). Do mobile phones not
    > implement this or is it possibly just a limitation in JABWT?
    >
    > We are currently using 3 phones for testing, SE p900, Nokia 6600 and
    > Siemens S65. All three phones have different behaviour as to how they
    > handle different events. And the SE p900 actually have an erroneous
    > JABWT implementation.
    >


    Hi,

    I have been working quite a lot with bluetooth and Nokia 6600. It is
    supposed to be able to connect up to 7 devices at the same time 9from
    the JSR82 if I am right), but Nokia 6600 has a limitation of being able
    to open only two connection at a time. That is, once you are connected
    to one device, the remaining connection is used for discovery. So you
    won't be able to connect to more than one device with a Nokia 6600.
    I have no clue about SE P900 or Siemens mobile.
    If you need some support, http://benhui.net is very useful (I have no
    link with this website, but recieved some good help at the time I was
    working on BT and J2ME).

    --
    JSC
    JScoobyCed, Mar 2, 2005
    #3
  4. JScoobyCed wrote:
    > Michael Sars Norum wrote:
    >
    >> Hi
    >>
    >> I'm currently working on a research project where we are developing a
    >> framework for ad hoc network based application on J2ME using Bluetooth
    >> as a reference implementation in the network layer.
    >>
    >> We currently have code running that connects to phones and allows them
    >> to communicate. However we have problems connecting three phones in a
    >> network.
    >>
    >> So far we have found that device discovery can not be done in parallel
    >> on the phones. Does this mean that we can not connect a phone to more
    >> than a single device at a time?
    >>
    >> We are currently using the RFCOMM protocal for communication, does
    >> this force any added restrictions as to how many connections can be
    >> open at once? The Bluetooth spec states that a Bluetooth piconet can
    >> consist of up to 8 devices (one master and 7 slaves). Do mobile phones
    >> not implement this or is it possibly just a limitation in JABWT?
    >>
    >> We are currently using 3 phones for testing, SE p900, Nokia 6600 and
    >> Siemens S65. All three phones have different behaviour as to how they
    >> handle different events. And the SE p900 actually have an erroneous
    >> JABWT implementation.
    >>

    >
    > Hi,
    >
    > I have been working quite a lot with bluetooth and Nokia 6600. It is
    > supposed to be able to connect up to 7 devices at the same time 9from
    > the JSR82 if I am right), but Nokia 6600 has a limitation of being able
    > to open only two connection at a time. That is, once you are connected
    > to one device, the remaining connection is used for discovery. So you
    > won't be able to connect to more than one device with a Nokia 6600.
    > I have no clue about SE P900 or Siemens mobile.
    > If you need some support, http://benhui.net is very useful (I have no
    > link with this website, but recieved some good help at the time I was
    > working on BT and J2ME).

    I've been reading a bit on http://benhui.net and have found two entries
    so far concerning the number of connections the 6600. One entry claims
    that the max number of connections is 2, while the other claims 6.

    We've been doing a lot of testing over the past two days and found out
    that the p900 have a hardware limitation of 1. If p900 connects to a
    remote device it seazes to be discoverable for anyone else. Both the
    6600 and the Siemens s65 are still discoverable and able to connect to
    other phones, if they for instance are connectet to a laptop.

    However the Bluetooth spec cleraly states that a Bluetooth-piconet can
    conatin up to 8 devices, (1 master and 7 slaves). But we have already
    found in other features of J2ME that the implementations often are not
    as specified.

    Regards
    Michael Sars Norum

    >
    > --
    > JSC
    >
    Michael Sars Norum, Mar 2, 2005
    #4
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