[ros-users] Wireless router/card recommendations

Sat Jun 12 03:42:39 UTC 2010

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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 did try the setup suggested by Cedric, where you connect an access point directly to your ethernet port and thus
bypass any driver issues. It does work better, we were seeing about speeds around 75mbit/s via TCP and 95mbit/s via UDP
(which might go higher, the AP we had lying around had 10/100 ethernet port). So, I think it will be our preferred setup
going forward unless we find some wifi card that can do N speeds under Linux.

We will be trying the 5GHz band in the next week or two, once we get the equipment, I will report back once I get some data.

Anton

On 06/11/2010 08:23 PM, Eric Perko wrote:
> Anton,
> 
> I was able to do some tests with the N router I have at home (WRT300n
> running DD-WRT) and WPA2 Personal encryption, and it sadly didn't look
> so good. Using iperf, measured speeds from a Thinkpad client with the
> Intel 4965agn to one of those Asus cards in my desktop, iperf only
> reported speeds around 1.5 Mbits/s (yup... those are the right units).
> I was able to get full 95ish Mbit/s out of a 100Mbit Ethernet link, so
> iperf should be functioning fine. I did notice that iwconfig only
> reported a bitrate of 54Mbits/s for the 4965, and I was able to bump
> it to some sort of auto mode and get speeds of around 50Mbit/s to a
> wired iperf server where I had previously gotten 3-5 Mbit/s. All of
> the systems involved are running Ubuntu 9.10 x64. My current
> hypothesis for the less than spectacular speeds reported by iperf is a
> combination of a few things:
> 
> * Poor autoconfiguration of the wireless N cards by Linux
> * Running my home router in a mixed mode because we have a few G-only
> clients, so maybe we cannot do full N speeds anyways
> * Tons of wireless interference in my apartment building... there
> really aren't any wide open channels between 1-11, so interference may
> be an important factor
> 
> I plan on trying to test the latter two once the lab N router
> reappears (it seems to have been loaned out and hasn't come back yet).
> I would also like to try it on an unencrypted network and see if that
> increases the speeds. The first is trickier and will require finding
> the right iwconfig commands... the ones I tried quickly with the Intel
> card didn't seem to put it into an N mode.
> 
> Though I did successfully change my rate on the Intel card to some
> sort of auto rate, I was unable to set it to a wireless N speed. Does
> anyone else have a wireless N setup (preferably N-only) that they
> could report the output of `iwconfig` for the bitrate value?
> 
> I guess the moral of the story from these tests is that just because
> there is some N equipment doesn't mean we are getting anything close
> to N speeds...
> 
> - Eric
> 
> On Wed, Jun 9, 2010 at 11:48 PM, Antons Rebguns <arebgun at gmail.com> wrote:
> Eric,
> 
>>>> We've been using one of these
>>>> http://www.newegg.com/product/product.aspx?Item=N82E16833320048 in our
>>>> system and it has been working quite well with Ubuntu 9.10. I can't
>>>> really comment on it's full speed potential doing 802.11n, as we only
>>>> have a WRT54G router, but it hasn't dropped out or had any problems
>>>> being recognized by Ubuntu like some of the other cards/USB adapters
>>>> we tried. Also, it goes on sale at MWave every so often for about $12,
>>>> which is helpful if you don't have a huge budget for Wifi cards.
> 
> Actually we do have a pretty good wireless G setup, I was thinking about something faster like wireless N. We do have an
> Intel 4965agn card that should support N speeds, but I was unable to get it to run any faster than G speeds (steady 60
> mbit/s though).
> 
>>>>
>>>> I could run some bandwidth tests or something with our WRT54G if you
>>>> give me some commands to run on each computer. I might also be able to
>>>> try it on a WRT610n, if I can find it in the lab.
>>>>
> 
> That would be great if you could test wireless N setup if you have one available. We have been using iperf to do
> bandwidth tests. It's in Ubuntu repos, just do "sudo apt-get install iperf". Then on one computer run "iperf -s" and on
> another run "iperf -c IP_ADDRESS_OF_ANOTHER_COMPUTER".
> 
> Thanks!
> Anton
> 
>>>> - Eric
>>>>
>>>> On Wed, Jun 9, 2010 at 8:36 PM, Antons Rebguns <anton at email.arizona.edu> wrote:
>>>>> Hello ROS users,
>>>>> We are updating our networking setup and I was wondering what other
>>>>> people/labs use on their robots? Something that is well supported in Linux
>>>>> and is fast, since network traffic is pretty significant with all the
>>>>> sensors/cameras running on the robot.
>>>>> Thanks,
>>>>> Anton
>>>>> _______________________________________________
>>>>> ros-users mailing list
>>>>> ros-users at code.ros.org
>>>>> https://code.ros.org/mailman/listinfo/ros-users
>>>>>
>>>>>
>>>> _______________________________________________
>>>> ros-users mailing list
>>>> ros-users at code.ros.org
>>>> https://code.ros.org/mailman/listinfo/ros-users
> 
>>

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