2009-02-26 11:59:45

by Mickael Chazaux

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Subject: Performance considerations

Hello,

I am programming with bluez in C, transfering data from a linux PC to a
java application on a phone. All works fine. I have some performance
questions.

When I use L2CAP sockets, I get an average of 10% better bitrate on a
given pair PC/phone than with RFCOMM sockets. Also, changing the MTU
of the L2CAP socket has an impact on bitrate. An MTU of 672 on some
phones gives a average bitrate of 190kB/s, nearly 50% more than with
an MTU of 256 bytes.

Also, in noisy environements (with lots and lots of phones with
bluetooth enabled), there is a great decrease in performance (
an average of 50kB/s with a good phone).

What bitrate values can you achieve? Can I expect an amelioration, for
example on fine tuning the stack's parameters, to get the maximum
bitrate possible?

Regards,
Mickael