802.11n AP mode

Live forum: http://rt2x00.serialmonkey.com/viewtopic.php?t=6197

Sunny

13-12-2011 22:47:21

Greetings,

i have DWA-140 rev. B2 adapter and kernel-3.1.5 driver rt2800 for it configured to work with hostapd in 802.11n AP mode. And there are some point that i would like to make clear. First if the kernel is compiled with the 'minstrel_ht' TX rate control algorithm enabled my AP experiences long periods of inactivity and low transfer speed of about 20-200 KB/s in between. Second if i disable the 'minstrel_ht' TX rate control algorithm and compile the kernel without it the bug disappears but AP tx-speed is about 3-4MB/s whereas its rx-speed is twice of that - 9-10Mb/s. So one could think that DWA-140 rev. B2 is 1t2r adapter. As far as i know it is based on Ralink RT3072 chipset which is 2t2r. Im confused at this point. Can you help me to setup this adapter at full speed or should i choose another adapter? Or maybe this is driver limitation?

Thank you.

p.s.
[i1l8fnz4t]"iw list" output[/i1l8fnz4t]

Wiphy phy0
Band 1
Capabilities 0x2f2
HT20/HT40
Static SM Power Save
RX Greenfield
RX HT20 SGI
RX HT40 SGI
TX STBC
RX STBC 2-streams
Max AMSDU length 3839 bytes
No DSSS/CCK HT40
Maximum RX AMPDU length 65535 bytes (exponent 0x003)
Minimum RX AMPDU time spacing 2 usec (0x04)
HT RX MCS rate indexes supported 0-15, 32
TX unequal modulation not supported
HT TX Max spatial streams 2
HT TX MCS rate indexes supported may differ

[i1l8fnz4t]my hostap config[/i1l8fnz4t]

channel=1
ht_capab=[HT40+][SHORT-GI-20][SHORT-GI-40][RX-STBC12][TX-STBC]
interface=wlan0
driver=nl80211
logger_syslog=-1
logger_syslog_level=2
logger_stdout=-1
logger_stdout_level=2
dump_file=/tmp/hostapd.dump
ctrl_interface=/var/run/hostapd
ctrl_interface_group=0
ssid=XXX
macaddr_acl=0
auth_algs=1
eap_server=0
eap_message=hello
eapol_key_index_workaround=0
own_ip_addr=127.0.0.1
ieee8021x=0
wpa_passphrase=*****************
wpa_key_mgmt=WPA-PSK WPA-EAP
wpa=1
wpa_pairwise=TKIP CCMP
hw_mode=g