Why periodically falls off wifi?

Question

WiFi

Collected the other day mini-nas on ubuntu 14.04.
It has a wifi card connected via PCI, through which the Internet is obtained from the router and the cross to a stationary computer, so that files cannot be transferred between them via wifi.
And periodically (about once a day) wifi stops working - it's impossible to connect to the server, in the router panel you can see that there is no connection from it. At the same time, the diode on the card blinks. Something like this is written in syslog .
I see people have similar problems ( one , two , three ) and it sudo service network-manager restarthelps, but I would like to eliminate the cause, not the consequences.
In the third question, they suggested adding the output of several commands, here they are:

lsmod

Module                  Size  Used by
ipw2100                90112  0 
libipw                 40960  1 ipw2100
lib80211               16384  1 libipw
ctr                    16384  1 
ccm                    20480  1 
rfcomm                 69632  0 
bnep                   20480  2 
bluetooth             491520  10 bnep,rfcomm
snd_hda_codec_realtek    81920  1 
snd_hda_codec_generic    69632  1 snd_hda_codec_realtek
snd_hda_codec_hdmi     53248  1 
kvm                   479232  0 
arc4                   16384  2 
rt2800pci              16384  0 
rt2800mmio             24576  1 rt2800pci
rt2800lib              90112  2 rt2800pci,rt2800mmio
rt2x00pci              16384  1 rt2800pci
rt2x00mmio             16384  2 rt2800pci,rt2800mmio
rt2x00lib              57344  5 rt2x00pci,rt2800lib,rt2800pci,rt2800mmio,rt2x00mmio
snd_hda_intel          36864  6 snd_hda_codec_hdmi
snd_hda_controller     32768  1 snd_hda_intel
mac80211              708608  3 rt2x00lib,rt2x00pci,rt2800lib
snd_hda_codec         143360  5 snd_hda_codec_realtek,snd_hda_codec_hdmi,snd_hda_codec_generic,snd_hda_intel,snd_hda_controller
snd_hwdep              20480  1 snd_hda_codec
serio_raw              16384  0 
snd_pcm               106496  4 snd_hda_codec_hdmi,snd_hda_codec,snd_hda_intel,snd_hda_controller
k10temp                16384  0 
cfg80211              524288  4 mac80211,rt2x00lib,libipw,ipw2100
amdkfd                 81920  1 
amd_iommu_v2           20480  1 amdkfd
eeprom_93cx6           16384  1 rt2800pci
crc_ccitt              16384  1 rt2800lib
shpchp                 40960  0 
snd_seq_midi           16384  0 
snd_seq_midi_event     16384  1 snd_seq_midi
i2c_piix4              24576  0 
radeon               1556480  3 
snd_rawmidi            32768  1 snd_seq_midi
snd_seq                65536  2 snd_seq_midi_event,snd_seq_midi
snd_seq_device         16384  3 snd_seq,snd_rawmidi,snd_seq_midi
snd_timer              32768  2 snd_pcm,snd_seq
snd                    86016  21 snd_hda_codec_realtek,snd_hwdep,snd_timer,snd_hda_codec_hdmi,snd_pcm,snd_seq,snd_rawmidi,snd_hda_codec_generic,snd_hda_codec,snd_hda_intel,snd_seq_device
ttm                    94208  1 radeon
drm_kms_helper        126976  1 radeon
drm                   344064  6 ttm,drm_kms_helper,radeon
soundcore              16384  2 snd,snd_hda_codec
i2c_algo_bit           16384  1 radeon
8250_fintek            16384  0 
mac_hid                16384  0 
parport_pc             32768  1 
ppdev                  20480  0 
lp                     20480  0 
parport                45056  3 lp,ppdev,parport_pc
pata_acpi              16384  0 
r8169                  81920  0 
ahci                   36864  3 
mii                    16384  1 r8169
libahci                32768  1 ahci
pata_atiixp            16384  0

iwconfig

eth0      no wireless extensions.

wlan0     IEEE 802.11bgn  ESSID:"koceg"  
          Mode:Managed  Frequency:2.442 GHz  Access Point: 50:67:F0:17:00:D4   
          Bit Rate=150 Mb/s   Tx-Power=27 dBm   
          Retry short limit:7   RTS thr:off   Fragment thr:off
          Power Management:off
          Link Quality=53/70  Signal level=-57 dBm  
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:26475  Invalid misc:8836   Missed beacon:0

lo        no wireless extensions.

If you can’t get to the bottom of the reasons, how can you check inside the server if there is a connection, so that if there is no connection, automatically restart network-manager?

Answer 1

cut down NetworkManager on nas it is not necessary to you - delete it in general.
set up /etc/network/interfaces once and scored.
+ why wi-fi for nas? throw the wire from the router along the plinth and do not suffer.