[ros-users] Wireless router/card recommendations

Markus Achtelik markus.achtelik at mavt.ethz.ch
Tue Jun 15 09:19:15 UTC 2010


Hi,

On Fri, 2010-06-11 at 20:42 -0700, Antons Rebguns wrote:
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> Eric,
> 
> Thank you so much for reporting your findings. They mirror exactly what I was seeing on our network. We also have an
> Intel 4965agn card on the robot, but we never got it to work in N mode, the maximum reported speed is always 54mbit/s.
> Although we were getting this maximum speed since we had very good signal strength and were close to the access point.

I was trying Intel 4965 cards as well, let's say with mixed success. I
got N working by compiling the latest version from
www.linuxwireless.org . It could also work with using the driver from
the backports. The maximum reported speed by iwlist was still 54
MBit/s . I haven't used iperf, but was scp'ing some large files between
two computer's RAMdisks (one of them wired) and got ~10 MByte/s when I
was close to the accespoint. With one wall in between, it dropped to ~ 2
MByte/s.

WPA2 works, but because of a bug just as long as you use AES encryption.

However, the 4965 didn't work reliably at all, when we were streaming
images continuously. As far as I know, not all parts of the Intel
drivers are open source and therefore these parts were somehow
reversed... 
What we observed was kernel panics caused by the 4569 and firmware
crashes :-(

Currently, we're using wireless cards with an Atheros 9280 chipset like
this one here: http://www.sparklan.com/product.php?func=view&prod_id=63

What also caused some trouble, was the Ubuntu network manager - we
uninstalled it and we're using WICD now.

Best, Markus



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