From: Alexandre Campo <Alexandre.Campo@ulb.ac.be>
To: bluez-users@lists.sourceforge.net
Subject: [Bluez-users] impact of distance on quality of transmission ?
Date: Tue, 21 Nov 2006 23:29:49 +0100 [thread overview]
Message-ID: <20061121232949.07b6fc6f@localhost.localdomain> (raw)
Hi,
I am working with a bunch of robots and I communicate with them using bluetooth connections.
I am trying to receive data from 7 robots at the same time.
For this, I simply connect to each robot using a program linked against libbluetooth,
that makes use of sockets and rfcomm.
Using only one robot, we manage to receive pretty well the data.
Using 7 robots things get complicated. If robots are close (~1 meter) from the bluetooth
dongle, we receive all the data.
As soon as the robots are far from the dongle (~2 meters and more) we start observing errors
in the data transmitted.
I am surprised because :
* we do not exceed the bt bandwidth (< 800 kb/s)
* we use SOCK_STREAM sockets that are supposed to be reliable
My questions :
* any idea of what causes these mistakes ?
* how to avoid transmission errors ?
Thanks a lot for your help,
Alexandre Campo.
------------------------------------------------------------------------
Details :
I use a belkin bt usb adapter (100m range)
info from usbview :
BCM92045DG Non-UHE
Manufacturer: Broadcom Corp
Speed: 12Mb/s (full)
USB Version: 2.00
The robots have
a bluetooth serial port module :
http://www.national.com/pf/LM/LMX9820A.html#General%20Description
a phycomp 2.45 GHz antenna :
http://www.phycomp-components.com/ (website unavailable ?)
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next reply other threads:[~2006-11-21 22:29 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-11-21 22:29 Alexandre Campo [this message]
-- strict thread matches above, loose matches on Subject: below --
2006-11-22 0:41 [Bluez-users] impact of distance on quality of transmission ? Pering, Trevor
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