Nanostation M5¶

Test 1¶

Compiled version 10.03.1-rc5 of openwrt with ath9k driver

In a shell on both machines (two NSm5):

iw wlan0 del
iw phy phy0 interface add wlan0 type ibss
ifconfig wlan0 192.168.2.X
iw dev wlan0 ibss join qmp 5785
iwconfig wlan0 essid qmp
iwconfig wlan0 txrate 15

In this point, you must have both devices connected:

wlan0     IEEE 802.11an  ESSID:`qmp`  
          Mode:Ad-Hoc  Frequency:5.785 GHz  Cell: 4E:0B:13:4B:29:E1   
          Tx-Power=15 dBm   
          RTS thr:off   Fragment thr:off
          Encryption key:off
          Power Management:on

Directly from both devices, with iperf these are the results:

[ ID] Interval       Transfer     Bandwidth
[  3]  0.0- 2.0 sec  3.13 MBytes  13.1 Mbits/sec
[  3]  2.0- 4.0 sec  3.00 MBytes  12.6 Mbits/sec
[  3]  4.0- 6.0 sec  2.88 MBytes  12.1 Mbits/sec

Seems that NSm5 CPU cannot generate more bits than 12Mbit/s.
So, I connect two computer, one in each side, and do the same test:

[ ID] Interval       Transfer     Bandwidth
[  4]  0.0-10.6 sec  23.5 MBytes  19.1 Mbits/sec
[  5]  0.0-10.6 sec  23.5 MBytes  21.3 Mbits/sec
[  4]  0.0-31.5 sec  69.1 MBytes  22.5 Mbits/sec

Better results, but seems that is only operating in HT20 (one channel).

I have been reading, and seems that you need a command like this to enable MiMo:

iw dev wlan0 ibss join qmp 5785 HT40+

But this option `HT40+` seems that for the moment is not accepted by the actual compat-wireless package.
Here: http://thread.gmane.org/gmane.linux.kernel.wireless.general/63191/focus=64279.
There is a patch to enable this option. The next step is try to compile compat-wireless.

Notes¶

1. This command does not work in ibss mode:
   

   iw wlan0 set freq 5785 HT40+

1. If you get an error like this:
   

   root@OpenWrt:~# iw dev wlan0 ibss join qmp 5785
   command failed: Operation already in progress (-149)
   

   
   Try to delete and create the interface.

1. Not all the channels are avaiable for ibss mode, you can see which ones are supported with:
   

   root@OpenWrt:~# iw phy phy0 info | grep MHz
               * 5180 MHz [36] (17.0 dBm)
               * 5200 MHz [40] (17.0 dBm)
               * 5220 MHz [44] (17.0 dBm)
               * 5240 MHz [48] (17.0 dBm)
               * 5260 MHz [52] (20.0 dBm) (passive scanning, no IBSS, radar detection)
               * 5280 MHz [56] (20.0 dBm) (passive scanning, no IBSS, radar detection)
               * 5300 MHz [60] (20.0 dBm) (passive scanning, no IBSS, radar detection)
               * 5320 MHz [64] (20.0 dBm) (passive scanning, no IBSS, radar detection)
               * 5500 MHz [100] (20.0 dBm) (passive scanning, no IBSS, radar detection)
               * 5520 MHz [104] (20.0 dBm) (passive scanning, no IBSS, radar detection)
               * 5540 MHz [108] (20.0 dBm) (passive scanning, no IBSS, radar detection)
               * 5560 MHz [112] (20.0 dBm) (passive scanning, no IBSS, radar detection)
               * 5580 MHz [116] (20.0 dBm) (passive scanning, no IBSS, radar detection)
               * 5600 MHz [120] (disabled)
               * 5620 MHz [124] (disabled)
               * 5640 MHz [128] (disabled)
               * 5660 MHz [132] (20.0 dBm) (passive scanning, no IBSS, radar detection)
               * 5680 MHz [136] (20.0 dBm) (passive scanning, no IBSS, radar detection)
               * 5700 MHz [140] (20.0 dBm) (passive scanning, no IBSS, radar detection)
               * 5745 MHz [149] (30.0 dBm)
               * 5765 MHz [153] (30.0 dBm)
               * 5785 MHz [157] (30.0 dBm)
               * 5805 MHz [161] (30.0 dBm)
               * 5825 MHz [165] (30.0 dBm)
   

Links¶

• iw reference: http://linuxwireless.org/en/users/Documentation/iw
• HT40+ discussion: http://thread.gmane.org/gmane.linux.kernel.wireless.general/63191/focus=64279.
• Patch for HT40+: http://ns3.spinics.net/lists/linux-wireless/msg50200.html

Seems that the last patch was too old. Here there is a new one:
http://www.spinics.net/lists/linux-wireless/msg67642.html

Also here you can read some information about ht40 and ibss:
http://comments.gmane.org/gmane.linux.drivers.ath9k.devel/4703