Skip to contentSkip to conversation

position of multiple bluetooth dongles

Bluez-users Marco Trudel 4 participants 9 messages Feb 10, 2005 – Feb 14, 2005 Bluetooth drivers

lore
Share & tools
lore
#0 lore raw

Hello everybody

Maybe someone knows this:
If two bluetooth dongles are used (a class1 and a class2), could it lead to signal interfereces/problems if they're just above each other and both have to send a lot of data at the same time?

With "right above each other", I mean this:
http://www1.ch2.conrad.com/m/7000_7999/7100/7160/7162/716282_LB_00_FB.EPS.jpg
(dongle cases are removed).

kind regards
Marco

-------------------------------------------------------
SF email is sponsored by - The IT Product Guide
Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now.
http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click
_______________________________________________
Bluez-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/bluez-users

#1 lore raw

As there is a very few chance that the use the same frequency at the=20 same time and send the same data, I think (hope?) there is no problem :)

Marco Trudel a =E9crit :

Quoted 4 lines

Hello everybody
=20
Maybe someone knows this:
If two bluetooth dongles are used (a class1 and a class2), could it lea=

d=20

Quoted 5 lines

to signal interfereces/problems if they're just above each other and=20 both have to send a lot of data at the same time?
=20
With "right above each other", I mean this:
http://www1.ch2.conrad.com/m/7000_7999/7100/7160/7162/716282_LB_00_FB.E=

PS.jpg=20

Quoted 11 lines

=20
(dongle cases are removed).
=20
=20
kind regards
Marco
=20
=20
-------------------------------------------------------
SF email is sponsored by - The IT Product Guide
Read honest & candid reviews on hundreds of IT Products from real users=

.

Quoted 7 lines

Discover which products truly live up to the hype. Start reading now.
http://ads.osdn.com/?ad_id=3D6595&alloc_id=3D14396&op=3Dclick
_______________________________________________
Bluez-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/bluez-users
=20

--=20
Gabriel Guillon

-------------------------------------------------------
SF email is sponsored by - The IT Product Guide
Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now.
http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click
_______________________________________________
Bluez-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/bluez-users

maintainer
#2 lore raw

Hi Gabriel,

Quoted 2 lines

As there is a very few chance that the use the same frequency at the same time and send the same data, I think (hope?) there is no problem :)

this might be one of 1600 per second. It is unlikely that the clock and the device address will be the same.

Regards

Marcel

-------------------------------------------------------
SF email is sponsored by - The IT Product Guide
Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now.
http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click
_______________________________________________
Bluez-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/bluez-users

#3 lore raw
In reply to Marco Trudel

BT 1.1 dongles may interference...
BT 1.2 only when comunication with 1.1 devices - 1.2 devices can never=20 interference

Michal

Dne =E8t 10. =FAnora 2005 18:13 Marco Trudel napsal(a):

Quoted 4 lines

Hello everybody

Maybe someone knows this:
If two bluetooth dongles are used (a class1 and a class2), could it lead =

to

Quoted 1 line

signal interfereces/problems if they're just above each other and both ha=

ve

Quoted 4 lines

to send a lot of data at the same time?

With "right above each other", I mean this:
http://www1.ch2.conrad.com/m/7000_7999/7100/7160/7162/716282_LB_00_FB.EPS=

=2Ej

Quoted 7 lines

pg (dongle cases are removed).

kind regards
Marco

Quoted 9 lines

-------------------------------------------------------
SF email is sponsored by - The IT Product Guide
Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now.
http://ads.osdn.com/?ad_id=3D6595&alloc_id=3D14396&op=3Dclick
_______________________________________________
Bluez-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/bluez-users

=2D-=20
S pozdravem

Michal Semler

-------------------------------------------------------
SF email is sponsored by - The IT Product Guide
Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now.
http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click
_______________________________________________
Bluez-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/bluez-users

maintainer
#4 lore raw

Hi Michal,

Quoted 3 lines

BT 1.1 dongles may interference...
BT 1.2 only when comunication with 1.1 devices - 1.2 devices can never interference

let me correct this. AFH is not for detecting used frequencies of other Bluetooth piconets. It only detects other wireless technologies, because for itself it is already protected by the hopping sequence itself. If it is the same hopping sequence it is the same piconet and thus it really wants to listen to its traffic.

Regards

Marcel

-------------------------------------------------------
SF email is sponsored by - The IT Product Guide
Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now.
http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click
_______________________________________________
Bluez-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/bluez-users

#5 lore raw

Hello Marcel

so it's no problem? no mather of the bluetooth version of the dongle? no interference, respectively maybe a couple if thousands in a second? corrected by rfcomm? the distance of two dongles doesn't matter?

regards
Marco

Quoted 20 lines · Marcel Holtmann

Hi Michal,

Quoted 2 lines

BT 1.1 dongles may interference...
BT 1.2 only when comunication with 1.1 devices - 1.2 devices can never interference

let me correct this. AFH is not for detecting used frequencies of other Bluetooth piconets. It only detects other wireless technologies, because for itself it is already protected by the hopping sequence itself. If it is the same hopping sequence it is the same piconet and thus it really wants to listen to its traffic.

Regards

Marcel

Quoted 11 lines

-------------------------------------------------------
SF email is sponsored by - The IT Product Guide
Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now.
http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click
_______________________________________________
Bluez-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/bluez-users

-------------------------------------------------------
SF email is sponsored by - The IT Product Guide
Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now.
http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click
_______________________________________________
Bluez-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/bluez-users

maintainer
#6 lore raw

Hi Marco,

Quoted 2 lines

so it's no problem? no mather of the bluetooth version of the dongle? no interference, respectively maybe a couple if thousands in a second?

ask an expert on the baseband level.

Quoted 1 line

corrected by rfcomm?

The error correction is done at the chip level. The ACL link is reliable.

Quoted 1 line

the distance of two dongles doesn't matter?

If the distance is bigger, the chip must request more retransmission. You won't see that in any of the BlueZ layers.

Regards

Marcel

-------------------------------------------------------
SF email is sponsored by - The IT Product Guide
Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now.
http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click
_______________________________________________
Bluez-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/bluez-users

#7 lore raw
In reply to Michal Semler

Hello Michael

thank you a lot for this information.
Another question regarding this topic:

Does it help/make any difference if the two dongles have a distance of ~11cm? Does this lead to equivalent/less interferences?
I have no idea about how radios send out their signals. I could imagine that if they spread their signal and there's another dongle just above the sending one that sends out a signal too, the interference is much worse than if they have a little distance, because the point of the problem is not right at the source.

Will rfcomm ensure the correctness of received data? something like a checksum and automatic retransmission of data if a brocken packet is recognized?

regards
Marco Trudel

Quoted 34 lines · Michal Semler

BT 1.1 dongles may interference...
BT 1.2 only when comunication with 1.1 devices - 1.2 devices can never interference

Michal

Dne čt 10. února 2005 18:13 Marco Trudel napsal(a):

Quoted 25 lines

Hello everybody

Maybe someone knows this:
If two bluetooth dongles are used (a class1 and a class2), could it lead to signal interfereces/problems if they're just above each other and both have to send a lot of data at the same time?

With "right above each other", I mean this:
http://www1.ch2.conrad.com/m/7000_7999/7100/7160/7162/716282_LB_00_FB.EPS.j
pg (dongle cases are removed).

kind regards
Marco

-------------------------------------------------------
SF email is sponsored by - The IT Product Guide
Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now.
http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click
_______________________________________________
Bluez-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/bluez-users

-------------------------------------------------------
SF email is sponsored by - The IT Product Guide
Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now.
http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click
_______________________________________________
Bluez-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/bluez-users

#8 lore raw

Safe distance is about 1m. in 1.1 dongles for 10 meters...10 meters for 1.1= =20
for 100 meters.

M.

Dne po 14. =FAnora 2005 7:13 Marco Trudel napsal(a):

Quoted 13 lines

Hello Michael

thank you a lot for this information.
Another question regarding this topic:

Does it help/make any difference if the two dongles have a distance of ~11cm? Does this lead to equivalent/less interferences?
I have no idea about how radios send out their signals. I could imagine that if they spread their signal and there's another dongle just above the sending one that sends out a signal too, the interference is much worse than if they have a little distance, because the point of the problem is not right at the source.

Quoted 24 lines

Will rfcomm ensure the correctness of received data? something like a checksum and automatic retransmission of data if a brocken packet is recognized?

regards
Marco Trudel

Quoted 16 lines · Michal Semler

BT 1.1 dongles may interference...
BT 1.2 only when comunication with 1.1 devices - 1.2 devices can never interference

Michal

Dne =E8t 10. =FAnora 2005 18:13 Marco Trudel napsal(a):

Quoted 9 lines

Hello everybody

Maybe someone knows this:
If two bluetooth dongles are used (a class1 and a class2), could it lead to signal interfereces/problems if they're just above each other and both have to send a lot of data at the same time?

With "right above each other", I mean this:
http://www1.ch2.conrad.com/m/7000_7999/7100/7160/7162/716282_LB_00_FB.E=

PS

Quoted 17 lines
Quoted 7 lines
Quoted 7 lines

.j pg (dongle cases are removed).

kind regards
Marco

Quoted 9 lines
Quoted 9 lines

-------------------------------------------------------
SF email is sponsored by - The IT Product Guide
Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now.
http://ads.osdn.com/?ad_id=3D6595&alloc_id=3D14396&op=3Dclick
_______________________________________________
Bluez-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/bluez-users

Quoted 9 lines

-------------------------------------------------------
SF email is sponsored by - The IT Product Guide
Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now.
http://ads.osdn.com/?ad_id=3D6595&alloc_id=3D14396&op=3Dclick
_______________________________________________
Bluez-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/bluez-users

=2D-=20
S pozdravem

Michal Semler

-------------------------------------------------------
SF email is sponsored by - The IT Product Guide
Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now.
http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click
_______________________________________________
Bluez-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/bluez-users