Hi,
Just curious, in this case, the class 2 BT cannot transmit
power to class 1 BT as the distance is way out of range, but
can class 1 BT transmit files to class 2 BT? since to class
1 BT the class 2 phone is in range?
--ken
Message: 2
Date: Wed, 11 Apr 2007 08:47:53 +1200
From: Thomas Kear <[email protected]>
Subject: Re: [Bluez-users] using class 1 dongle
To: BlueZ users <[email protected]>
Message-ID: <[email protected]>
Content-Type: text/plain; charset="iso-8859-15"
On Wed, 11 Apr 2007, siddhant tewari wrote:
> Really great to get a answer ... i think my mobile phone
> has class 2 bt adapter ... but this issue is a real shock for me ... i
> thought if any of the devices has a good range , communication channel will
> be established and data transfer will take place , but all this theory goes
> in vain .
The problem is as simple as transmit power. As wikipedia helpfully
shows
(http://en.wikipedia.org/wiki/Bluetooth#Uses), class 1 devices can have
40
times the transmit power of class 2 devices, the class 1 connecting to
class
2 problem comes down to that past a certain range, the class 2 device
does
not have a high enough transmit power for its signal to reach the
reciever
(2.4GHz signals are eaten particularly fast by everything in their path,
including air).
As i outlined before, the higher transmit power in a class 1 device will
come
coupled to a higher sensitivity reciever, but that's not going to get
you
100m. If you had got the 30-40 metres you were attempting in your
original
email you would have been extremely lucky.
The problem is there are very few phones that come with class 1
bluetooth,
100mW transmit power is a little hard on battery life. If you want a
challenge though, find a class1 bluetooth adapter that has a dipole
aerial
rather than the usual circuit board trace and attach a bigger one.
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what i think is that for any kind of transfer to take place (for e.g. via
obex push or obex ftp profile) both way handshakes are necessary to
instantiate the transfer ....
Just curious, in this case, the class 2 Bdshannot transmit
> power to class 1 BT as the distance is way out of range, but
> can class 1 BT transmit files to class 2 BT? since to class
> 1 BT the class 2 phone is in range?
>
> --ken
>
> Message: 2
> Date: Wed, 11 Apr 2007 08:47:53 +1200
> From: Thomas Kear <[email protected]>
> Subject: Re: [Bluez-users] using class 1 dongle
> To: BlueZ users <[email protected]>
> Message-ID: <[email protected]>
> Content-Type: text/plain; charset="iso-8859-15"
>
> On Wed, 11 Apr 2007, siddhant tewari wrote:
> > Really great to get a answer ... i think my mobile
> phone
> > has class 2 bt adapter ... but this issue is a real shock for me ... i
> > thought if any of the devices has a good range , communication channel
> will
> > be established and data transfer will take place , but all this theory
> goes
> > in vain .
> The problem is as simple as transmit power. As wikipedia helpfully
> shows
> (http://en.wikipedia.org/wiki/Bluetooth#Uses), class 1 devices can have
> 40
> times the transmit power of class 2 devices, the class 1 connecting to
> class
> 2 problem comes down to that past a certain range, the class 2 device
> does
> not have a high enough transmit power for its signal to reach the
> reciever
> (2.4GHz signals are eaten particularly fast by everything in their path,
> including air).
>
> As i outlined before, the higher transmit power in a class 1 device will
> come
> coupled to a higher sensitivity reciever, but that's not going to get
> you
> 100m. If you had got the 30-40 metres you were attempting in your
> original
> email you would have been extremely lucky.
>
> The problem is there are very few phones that come with class 1
> bluetooth,
> 100mW transmit power is a little hard on battery life. If you want a
> challenge though, find a class1 bluetooth adapter that has a dipole
> aerial
> rather than the usual circuit board trace and attach a bigger one.
> -------------- next part --------------
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> Name: not available
> Type: application/pgp-signature
> Size: 189 bytes
> Desc: not available
>
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>
> -------------------------------------------------------------------------
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> Join SourceForge.net's Techsay panel and you'll get the chance to share
> your
> opinions on IT & business topics through brief surveys-and earn cash
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