I am presently experiencing random disconnections from my wireless network. It looks like it is becoming more and more frequent (however I have not seen any clear pattern).
This is killing me...
Basically at some point the wifi network stops being detected and i CANNOT SEE ANY NETWORK ANYMORE like if the network card was shut down

Below is some information that should help as well as one attempt to fix it (from Ubuntu forums).

Machine: Acer Aspire S3 (exact model no. Aspire S3-951-2464G34iss)

statquant@euclide:~$ lsb_release -d

Description:    Ubuntu 12.04.1 LTS



statquant@euclide:~$ uname -mr

3.2.0-33-generic x86_64

statquant@euclide:~$ 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...

statquant@euclide:~$ lspci

02:00.0 Network controller: Atheros Communications Inc. AR9485 Wireless Network Adapter (rev 01)

statquant@euclide:~$ lsusb

Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

Bus 001 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub

Bus 002 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub

Bus 001 Device 004: ID 064e:c321 Suyin Corp. 

Bus 002 Device 003: ID 0bda:0129 Realtek Semiconductor Corp.

statquant@euclide:~$ ifconfig

wlan0     Link encap:Ethernet  HWaddr 74:de:2b:dd:c4:78  

          inet addr:192.168.1.3  Bcast:192.168.1.255  Mask:255.255.255.0

          inet6 addr: fe80::76de:2bff:fedd:c478/64 Scope:Link

          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

          RX packets:913 errors:0 dropped:0 overruns:0 frame:0

          TX packets:802 errors:0 dropped:0 overruns:0 carrier:0

          collisions:0 txqueuelen:1000 

          RX bytes:873218 (873.2 KB)  TX bytes:125826 (125.8 KB)

statquant@euclide:~$ iwconfig

wlan0     IEEE 802.11bgn  ESSID:"Bbox-D646D1"  

          Mode:Managed  Frequency:2.437 GHz  Access Point: 00:19:70:80:01:6C   

          Bit Rate=65 Mb/s   Tx-Power=16 dBm   

          Retry  long limit:7   RTS thr:off   Fragment thr:off

          Power Management:on

          Link Quality=56/70  Signal level=-54 dBm  

          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0

          Tx excessive retries:0  Invalid misc:71   Missed beacon:0

statquant@euclide:~$ dmesg | grep "wlan"

[   17.495866] ADDRCONF(NETDEV_UP): wlan0: link is not ready

[   17.498950] ADDRCONF(NETDEV_UP): wlan0: link is not ready

[   20.072015] wlan0: authenticate with 00:19:70:80:01:6c (try 1)

[   20.269853] wlan0: authenticate with 00:19:70:80:01:6c (try 2)

[   20.272386] wlan0: authenticated

[   20.298682] wlan0: associate with 00:19:70:80:01:6c (try 1)

[   20.302321] wlan0: RX AssocResp from 00:19:70:80:01:6c (capab=0x431 status=0 aid=1)

[   20.302325] wlan0: associated

[   20.307307] ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready

[   30.402292] wlan0: no IPv6 routers present

statquant@euclide:~$ sudo lshw -C network

[sudo] password for statquant: 

*-network               

   description: Wireless interface

   product: AR9485 Wireless Network Adapter

   vendor: Atheros Communications Inc.

   physical id: 0

   bus info: pci@0000:02:00.0

   logical name: wlan0

   version: 01

   serial: 74:de:2b:dd:c4:78

   width: 64 bits

   clock: 33MHz

   capabilities: pm msi pciexpress bus_master cap_list rom ethernet physical wireless

   configuration: broadcast=yes driver=ath9k driverversion=3.2.0-33-generic firmware=N/A ip=192.168.1.3 latency=0 link=yes multicast=yes wireless=IEEE 802.11bgn

   resources: irq:17 memory:c0400000-c047ffff memory:afb00000-afb0ffff

statquant@euclide:~$ iwlist scan

wlan0     Scan completed :

      Cell 01 - Address: 00:19:70:80:01:6C

                Channel:6

                Frequency:2.437 GHz (Channel 6)

                Quality=56/70  Signal level=-54 dBm  

                Encryption key:on

                ESSID:"Bbox-D646D1"

                Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 6 Mb/s

                          9 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=000000125fb152bb

                Extra: Last beacon: 40020ms ago

                IE: Unknown: 000B42626F782D443634364431

                IE: Unknown: 010882848B960C121824

                IE: Unknown: 030106

                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

                IE: Unknown: DD180050F2020101820003A4000027A4000042435E0062322F00

                IE: Unknown: 2D1A4C101BFF00000000000000000000000000000000000000000000

                IE: Unknown: 3D1606080800000000000000000000000000000000000000

                IE: Unknown: DD0900037F01010000FF7F

                IE: Unknown: DD0A00037F04010000000000

I did the following (after looking for fixes of similar problems), but unfortunately
this fails to fix my issue.

sudo modprobe -r iwlwifi 

sudo modprobe iwlwifi 11n_disable=1

This is a snapshot I obtained via iwscanner, as you can see even when the wifi is working there is small losses

I did this following the following this thread, worked well for a few hour but I got a disconnection :(
Here is what I did:

statquant@euclide:~$ sudo modprobe -rfv ath9k

[sudo] password for statquant: 

rmmod /lib/modules/3.2.0-34-generic/kernel/drivers/net/wireless/ath/ath9k/ath9k.ko

rmmod /lib/modules/3.2.0-34-generic/kernel/net/mac80211/mac80211.ko

rmmod /lib/modules/3.2.0-34-generic/kernel/drivers/net/wireless/ath/ath9k/ath9k_common.ko

rmmod /lib/modules/3.2.0-34-generic/kernel/drivers/net/wireless/ath/ath9k/ath9k_hw.ko

rmmod /lib/modules/3.2.0-34-generic/kernel/drivers/net/wireless/ath/ath.ko

rmmod /lib/modules/3.2.0-34-generic/kernel/net/wireless/cfg80211.ko

statquant@euclide:~$ sudo modprobe -v ath9k nohwcrypt=1

insmod /lib/modules/3.2.0-34-generic/kernel/net/wireless/cfg80211.ko 

insmod /lib/modules/3.2.0-34-generic/kernel/drivers/net/wireless/ath/ath.ko 

insmod /lib/modules/3.2.0-34-generic/kernel/drivers/net/wireless/ath/ath9k/ath9k_hw.ko 

insmod /lib/modules/3.2.0-34-generic/kernel/drivers/net/wireless/ath/ath9k/ath9k_common.ko 

insmod /lib/modules/3.2.0-34-generic/kernel/net/mac80211/mac80211.ko 

insmod /lib/modules/3.2.0-34-generic/kernel/drivers/net/wireless/ath/ath9k/ath9k.ko nohwcrypt=1