Running Debian "Jessie" with Gnome 3.8 on a desktop PC with a USB thumb-size wireless adapter. Network has good signal strength (computer is 8 feet from wireless router).

I'm able to connect just fine to my home wireless network, but after a random period of time (sometimes a couple hours, sometimes more), the wireless connection drops. Than, when I click the network icon on the Gnome panel, I find that my home network has disappeared from the list of available wireless networks. If I turn the Gnome "Wi-Fi" toggle off and then back on, it reconnects automatically and the network appears on the list again.

This problem existed before the upgrade to Jessie and Gnome 3.8, so it's not the result of recent changes to the OS/Shell.

All other computers on the wireless network (several Windows machines and one other Debian machine) stay connected consistently.

Any help is appreciated. Thanks!

Sounds like your usb thingy is drawing too much power. The usb sockets won't give more than 100mA and then they switch off. So the port goes awol. Some of those things draw less than 100mA.

Hm...I'll see if I can find another USB unit and see if it behaves the same way. The strange thing is that, when the connection gets dropped, I can still see my next-door neighboors' wireless networks in the list...just not my own network. It seems that the USB unit is at least doing something...

or it picked a beacon in the last while from it. That usb thing was a guess. You gave us basically nothing to go on, so nobody could do anything else. See if you get it up, what quality does it show in .

Another way of checking it iof you have/can borrow a smart phone is to tether the system so it has a wifi that way. If that stays going, you can be fairly sure I'm close. Ebay have those wifi things for under a tenner.

Here's the result of iwlist wlan0 scan:

wlan0 Interface doesn't support scanning.

I realize I didn't provide much information...I'm a mostly non-technical user who would love some guidance as to the terminal commands, etc. that will provide helpful diagnostic info.

instead of wlan0 try eth1. That's the other favourite name, though not always.

I forget what debian uses - I'll have to boot my Pi to check.

You are running debian?

On a whim I tried running the scan on wlan1 rather than wlan0. Here's the result:

wlan1 Scan completed :
Cell 01 - Address: 00:00:00:00:00:00
Channel:6
Frequency:2.437 GHz (Channel 6)
Quality=60/70 Signal level=-50 dBm
Encryption keyn
ESSID:"Altered"
Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 6 Mb/s
12 Mb/s; 24 Mb/s; 36 Mb/s
Bit Rates:9 Mb/s; 18 Mb/s; 48 Mb/s; 54 Mb/s
Mode:Master
Extra:tsf=0000004a4a95b640
Extra: Last beacon: 12ms ago
IE: Unknown: 000644654C617933
IE: Unknown: 010882848B960C183048
IE: Unknown: 030106
IE: Unknown: DD0600032F010001
IE: Unknown: 2A0100
IE: Unknown: 32041224606C
IE: Unknown: DD0900037F010100170000
IE: Unknown: DD0C00037F0201012E0002A44000
Cell 02 - Address: 00:00:00:00:00:00
Channel:1
Frequency:2.412 GHz (Channel 1)
Quality=37/70 Signal level=-73 dBm
Encryption keyn
ESSID:"Altered"
Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 18 Mb/s
24 Mb/s; 36 Mb/s; 54 Mb/s
Bit Rates:6 Mb/s; 9 Mb/s; 12 Mb/s; 48 Mb/s
Mode:Master
Extra:tsf=0000004c268bcf70
Extra: Last beacon: 12ms ago
IE: Unknown: 0009484F4D452D33413330
IE: Unknown: 010882848B9624B0486C
IE: Unknown: 030101
IE: Unknown: 2A0100
IE: Unknown: 2F0100
IE: IEEE 802.11i/WPA2 Version 1
Group Cipher : TKIP
Pairwise Ciphers (2) : CCMP TKIP
Authentication Suites (1) : PSK
IE: Unknown: 32048C129860
IE: Unknown: 2D1AFD181BFFFFFF0000000000000000000000000000000000000000
IE: Unknown: 3D1601081500000000000000000000000000000000000000
IE: Unknown: DD8C0050F204104A0001101044000102103B0001031047001001B7BE5055F8E6789D92F93DBA2249D31021000B546563686E 69636F6C6F721023000B546563686E69636F6C6F721024000631323334353610420007303030303030311054000800060050 F20400011011000D546563686E69636F6C6F724150100800022008103C0001011049000600372A000120
IE: Unknown: DD090010180203F03C0000
IE: WPA Version 1
Group Cipher : TKIP
Pairwise Ciphers (2) : CCMP TKIP
Authentication Suites (1) : PSK
IE: Unknown: DD180050F2020101800003A4000027A4000042435E0062322F00
Cell 03 - Address: 00:00:00:00:00:00
Channel:10
Frequency:2.457 GHz (Channel 10)
Quality=35/70 Signal level=-75 dBm
Encryption keyn
ESSID:"Altered"
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=0000011536c6a5fc
Extra: Last beacon: 18672ms ago
IE: Unknown: 000B4C41555241205749464920
IE: Unknown: 010882848B0C12961824
IE: Unknown: 03010A
IE: Unknown: 0706555320010B1B
IE: IEEE 802.11i/WPA2 Version 1
Group Cipher : TKIP
Pairwise Ciphers (2) : CCMP TKIP
Authentication Suites (1) : PSK
IE: WPA Version 1
Group Cipher : TKIP
Pairwise Ciphers (2) : CCMP TKIP
Authentication Suites (1) : PSK
IE: Unknown: 2A0100
IE: Unknown: 32043048606C

Just commenting on that:
Quality of 60/70 is loads of signal

Encryption is always a good idea and you're associated, that is online. The piece in bold is your (edited)router's Mac Address. Generally better not send out passwords, and sensitive data (Like the mac address and essid).

I meant to add: If it's dropping out at that sort of range from your hotspot, it's not signal, so you must go looking for some other source. If it drops out again, grab a terminal and run
If my guess is correct, you may not see your wifi thingy in the list, because the port is off.

Here's the result of lsusb, when the connection has dropped:

Bus 005 Device 004: ID 0846:4260 NetGear, Inc. WG111v3 54 Mbps Wireless [realtek RTL8187B]
Bus 005 Device 013: ID 0bc2:a013 Seagate RSS LLC
Bus 005 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 004 Device 002: ID 045e:0039 Microsoft Corp. IntelliMouse Optical
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 002 Device 002: ID 1c4f:0002 SiGma Micro Keyboard TRACER Gamma Ivory
Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 001 Device 002: ID 04e8:326c Samsung Electronics Co., Ltd ML-2010P Mono Laser Printer
Bus 001 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub

As mentioned in one of my other replies, it is just my home network that disappears from the list of available wireless networks, while other wireless networks (my next-door neighbors') remain on the list. I don't think wireless neworking itself has ever stopped working or that the OS has stopped "seeing" my usb device. I just lose the ability to connect to my particular router/network until I switch wireless networking off and then back on, at which point my network magically appears again. Could this be a problem with my router settings? I tried turning off "Super G" acceleration on the router, but that didn't help.

That's your usb wifi thing showing, I take it?
It's beginning to look like your wifi router, or it's power supply. Is it rebooting?

There are a few options:

If it's a laptop, take it to a wifi hotspot, and run it there for a whiole.
Change the channel you are using, & the wifi password.

When it goes, ping 192.168.0.1 or whatever your web setup address is. I presume you won't get it, but the error might be illuminating.

I set the router to consistently assign the same IP address to my PC, and I changed the wireless channel for the network. Since changing the channel it's been 24 hours or more, and the connection hasn't dropped, so maybe that was the fix, though Ihave no idea what the problem is. Though it's possible the router was periodically rebooting, all of the other computers on the wireless network (some windows machines and a Debian) remained connected (or at least were able to automatically reconnect if the router was rebooting).

Thanks for your help!

I'll leave this thread open for a couple more days and make sure things stay connected before marking it SOLVED...

There's a few strange propogation effects that can cause that. I'll spare you the lecture on electronics, but I'm not surprised.