Return-Path: Message-Id: <1176368621.4287.1184217917@webmail.messagingengine.com> From: "Kenneth Liew Jau Tze" To: bluez-users@lists.sourceforge.net MIME-Version: 1.0 Date: Thu, 12 Apr 2007 17:03:41 +0800 Subject: Re: [Bluez-users] using class 1 dongle Reply-To: BlueZ users List-Id: BlueZ users List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Sender: bluez-users-bounces@lists.sourceforge.net Errors-To: bluez-users-bounces@lists.sourceforge.net 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 Subject: Re: [Bluez-users] using class 1 dongle To: BlueZ users Message-ID: <200704110847.58296.thomas.kear@gmail.com> 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 -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 189 bytes Desc: not available ------------------------------ ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT 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 http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Bluez-users mailing list Bluez-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bluez-users