Wireless troubles, Ubuntu 12.04, Ralink RT2571W wireless card, HP Pavilion m9040n

[aqualung347]

Hello everyone, I would be grateful for some help. I'm a newcomer to Ubuntu, coming from Windows. I've searched on the forums and haven't really found anything, but since I'm unfamiliar with the lingo, I didn't understand everything I was seeing.

So here is my problem (which is more of an annoyance than a catastrophe): my wireless card connects to the internet, but sometimes after a while it will drastically slow down or stop working completely. At the same time, when I click on the wireless icon at the top right of the screen, it still says it is connected to the network. If I try to restart the computer, it tends to get stuck on the shutting down screen, and I end up having to do a hard reboot. But once it does reboot, the network is working again.

Information about my system:
HP Pavilion m9040n (HP lists the components here: http://h20000.www2.hp.com/bizsupport...ctID=c01154933)
Dual-booting Ubuntu 12.04 LTS and Windows 7
Wireless card: Gemtek WUBR-177G [Ralink RT2571W]
As far as I can tell, the driver is rt73usb
Results of $ iwconfig:

wlan0 IEEE 802.11bg ESSID:"36PA3"
Mode:Managed Frequency:2.412 GHz Access Point: 00:1D:19:DE:1B:B4
Bit Rate=48 Mb/s Tx-Power=20 dBm
Retry long limit:7 RTS thr:off Fragment thr:off
Power Management:on
Link Quality=38/70 Signal level=-72 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:490 Invalid misc:356 Missed beacon:0

Results of $ lsmod:

Module Size Used by
vesafb 13844 1
arc4 12529 2
snd_hda_codec_hdmi 32474 4
nvidia 12336440 40
parport_pc 32866 0
ppdev 17113 0
rfcomm 47604 0
bnep 18281 2
bluetooth 180104 10 rfcomm,bnep
snd_hda_codec_realtek 223962 1
rt73usb 31735 0
rt2x00usb 20762 1 rt73usb
rt2x00lib 51144 2 rt73usb,rt2x00usb
mac80211 506816 2 rt2x00usb,rt2x00lib
snd_hda_intel 33773 5
snd_hda_codec 127706 3 snd_hda_codec_hdmi,snd_hda_codec_realtek,snd_hda_i ntel
snd_hwdep 13668 1 snd_hda_codec
cfg80211 205544 2 rt2x00lib,mac80211
snd_pcm 97188 3 snd_hda_codec_hdmi,snd_hda_intel,snd_hda_codec
snd_seq_midi 13324 0
snd_rawmidi 30748 1 snd_seq_midi
snd_seq_midi_event 14899 1 snd_seq_midi
snd_seq 61896 2 snd_seq_midi,snd_seq_midi_event
snd_timer 29990 2 snd_pcm,snd_seq
snd_seq_device 14540 3 snd_seq_midi,snd_rawmidi,snd_seq
serio_raw 13211 0
snd 78855 20 snd_hda_codec_hdmi,snd_hda_codec_realtek,snd_hda_i ntel,snd_hda_codec,snd_hwdep,snd_pcm,snd_rawmidi,s nd_seq,snd_timer,snd_seq_device
mac_hid 13253 0
soundcore 15091 1 snd
snd_page_alloc 18529 2 snd_hda_intel,snd_pcm
lp 17799 0
parport 46562 3 parport_pc,ppdev,lp
usbhid 47199 0
hid 99559 1 usbhid
firewire_ohci 41000 0
firewire_core 63558 1 firewire_ohci
crc_itu_t 12707 2 rt73usb,firewire_core
e1000e 156693 0

Network configuration:

*-network
description: Wireless interface
physical id: 1
bus info: usb@2:6
logical name: wlan0
serial: 00:c0:a8:ff:12:a3
capabilities: ethernet physical wireless
configuration: broadcast=yes driver=rt73usb driverversion=3.2.0-27-generic firmware=1.7 ip=192.168.1.7 link=yes multicast=yes wireless=IEEE 802.11bg

Result of $ iwlist scan:

wlan0 Scan completed :
Cell 01 - Address: 00:1D:19:DE:1B:B4
Channel:1
Frequency:2.412 GHz (Channel 1)
Quality=36/70 Signal level=-74 dBm
Encryption key:on
ESSID:"36PA3"
Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 6 Mb/s; 9 Mb/s
11 Mb/s; 12 Mb/s; 18 Mb/s
Bit Rates:24 Mb/s; 36 Mb/s; 48 Mb/s; 54 Mb/s
Mode:Master
Extra:tsf=00000001f7535895
Extra: Last beacon: 20400ms ago
IE: Unknown: 00053336504133
IE: Unknown: 010882848B0C12961824
IE: Unknown: 030101
IE: Unknown: 2A0100
IE: Unknown: 32043048606C

~$ uname -mr
3.2.0-27-generic x86_64

sudo /etc/init.d/networking restart
* Running /etc/init.d/networking restart is deprecated because it may not enable again some interfaces
* Reconfiguring network interfaces... [ OK ]

Anyone have an idea what might be going wrong? Does my description of the problem make sense?

[chili555]

As far as I can tell, the driver is rt73usb

Correct.

Does my description of the problem make sense?

Perfectly. I suspect most of your problem is here:

wlan0 IEEE 802.11bg ESSID:"36PA3"
Mode:Managed Frequency:2.412 GHz Access Point: 00:1D:19:DE:1B:B4
Bit Rate=48 Mb/s Tx-Power=20 dBm
Retry long limit:7 RTS thr:off Fragment thr:off
Power Management:on
Link Quality=38/70 Signal level=-72 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:490 Invalid misc:356 Missed beacon:0

I suggest you do anything you can to get the signal quality improved. Rearrange the antenna(s) on the router; try channels 1 or 11. See if there is a power setting in the administration pages of the router. Can it be moved to a higher level?

We might try two things temporarily. These will disappear on reboot but can be made persistent if they help. Please open a terminal and do:

sudo iwconfig wlan0 power off

Any improvement? Also try:

sudo modprobe -r rt73usb
sudo modprobe rt73usb nohwcrypt=Y

Now is there any improvement?

[aqualung347]

Thanks for the help, Chili. I'm going to see what I can do to boost the signal. Step one is finding out the username and password for the router--I have permission to use the network, but it doesn't belong to me. The terminal commands you gave me were some help, though.

 sudo iwconfig wlan0 power off

I let it run for 12 minutes with no result, then closed the terminal.

 sudo modprobe -r rt73usb
sudo modprobe rt73usb nohwcrypt=Y

This shut off the connection, and then had it working again. Good enough for now.

I'm also interested in learning about terminal commands. Am I right in thinking that the last two lines remove the driver from the kernel, then load it again without hardware encryption?

[chili555]

I let it run for 12 minutes with no result, then closed the terminal.

It isn't really a command that 'runs.' It turns off power management which sometimes makes instability in wireless drivers. If it had no effect, then we can skip it.

Am I right in thinking that the last two lines remove the driver from the kernel, then load it again without hardware encryption?

Correct. Sometimes hardware encryption works better and sometimes software, as you have seen. We need to write a conf file to make it persistent.

sudo gedit /etc/modprobe.d/rt73usb.conf

Use leafpad, kate, vim or any other text editor if you don't have gedit. Add one single line to the new empty file:

options rt73usb nohwcrypt=Y

Proofread, save and close gedit. You should be all set.

Learn more about available driver parameters with:

modinfo rt73usb

In this case it is the only parameter available to manipulate.