Re: [gentoo-user] Wireless: Limit rate to strengthen connection?

[Richard Marzan]

On Wed, 2008-03-26 at 19:52 -0700, Grant wrote:
> > >  > >  > I'm trying to strengthen a wireless connection that spans about 150
> >  >  > >  > feet and has to go through about 5 walls.  I bought two of these:
> >  >  > >  >
> >  >  > >  > http://www.newegg.com/Product/Product.aspx?Item=N82E16833164110
> >  >  > >  >
> >  >  > >  > for either end of the connection, but I'm having trouble making it
> >  >  > >  > work well.  I've noticed the connection will be perfect for a short
> >  >  > >  > time, but then disappear.  When watching iwconfig during this process,
> >  >  > >  > it looks like the connection is good when on a low rate, but when it
> >  >  > >  > goes to 54 Mbps it falls apart.
> >  >  > >  >
> >  >  > >  > Should limiting the rate solve this problem?  If so, how can I do
> >  >  > >  > that?  I'm using hostapd on the AP and wpa_supplicant on the client.
> >  >  > >  >
> >  >  > >  > - Grant
> >  >  > >
> >  >  > >  Grant,
> >  >  > >
> >  >  > >  Yes, lowering the rate to a "slower" speed will help greatly.  The lower
> >  >  > > rates use less compression and modulation... less complex wave forms
> >  >  > > better connects over long hauls.
> >  >  > >
> >  >  > >  The antennas look very good, but what's driving them? I use and whole
> >  >  > >  heartedly endorse SENAO products and have had very good luck with these
> >  >  > >  models:   ECB-3220 (400 mw) or 2611CB3 PLUS (200 mw) at:
> >  >  > >  http://www.wlansolution.com. Either unit with the high gain antennas you
> >  >  > >  have,  will penetrate what you stated and probably go pretty high on the
> >  >  > >  speed scale doing it too.
> >  >  >
> >  >  > I'm using a Netgear PCI adapter on the AP and an Edimax USB adapter on
> >  >  > the client.  Do you know how I can limit the rate?  Should it be done
> >  >  > on the Gentoo AP or the client?
> >  >  >
> >  >  > - Grant
> >  >
> >  >  I use wireless-tools from portage. In it is iwconfig. A simple man iwconfig
> >  >  will show you what you need. Other thing you could do is configure the
> >  >  Wireless AP for a fixed rate... works for me.
> >
> >  I found this:
> >
> >  rate_wlan0=( "5.5M" )
> >
> >  which isn't documented in net.wireless, but it doesn't seem to have
> >  any affect.  I've tried it on the router and the client which uses
> >  wpa_supplicant.  I still see the rate on the client fluctuate all the
> >  way up to 54 Mb/s in the output from iwconfig.  The router's rate is
> >  always reported as 0 kb/s.
> >
> >  - Grant
>
> It appears 'iwconfig wlan0 rate 11M' works (at least as far as the
> output from iwconfig is concerned) but how can I set /etc/conf.d/net
> to always use this rate?
>
> - Grant

The best way I found to do this is to just write your own script and run
it at the default runlevel. write a script called wireless-up save it in
your /root directory. Then in /etc/conf.d/local.start add the script
name to the list: /root/wireless-up. Make sure the script is executable
with chmod 666 /root/wireless-up. Here is what mine looks like. I laugh
when I read this thing that I call a script. I'll be upgrading this in
the future but for now maybe someone has a better idea and/or script.

#!/bin/bash
DATE=`date +%m_%d_%Y`
ifconfig wlan0 up || "echo wlan up failed"
iwconfig wlan0 essid ACCESSPOINTNAME || "echo setting essid failed"
iwconfig wlan0 mode Managed || echo "setting mode to managed failed"
iwconfig wlan0 key restricted YOURKEYHERE || echo "key failed
verification"
dhclient wlan0 || echo "wlan0 failed to receive dhcp request response"
# if [ $DATE -ne `date +%m_%d_%Y -r /tmp/.wireless.*
rm /tmp/.wireless.* 
iwconfig >> /tmp/.wireless.$DATE
exit 0



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