When using Ubuntu, connected to the WiFi, there may be a connection disconnection phenomenon (WiFi display has been connected, but not on the network, each time the WiFi reconnect, you can briefly connect, but soon will be disconnected, through the network cable does not exist this problem).
This typically requires checking your wireless card driver (viewed via the lspci command), searching the web for General Intel Wireless Card This happens (my laptop is using an old Intel Wireless card – the 2010 machine).
The wireless adapter model is:
Network Controller:intel Corporation Centrino wireless-n 1000
Drivers used:
Driver:iwlwifi
Version:3.2.0-32-generic-pae
firmware-version:39.31.5.1 Build 35138
This drive has not been updated since 04 years ...
Solution:
Turn off the 802.11n support can be connected, it may be the driver of the 04 11n support and now some manufacturers some bugs.
Terminal operation
sudo gedit/etc/modprobe.d/iwlwifi.conf
Add this sentence.
#关闭802.11n support, the speed will have a limit of 54Mbps (802.11g mode), does not affect the use (unless your home network over 50Mbps).
Options Iwlwifi 11n_disable=1
Terminal operation
sudo modprobe-r Iwlwifi
sudo modprobe Iwlwifi
Ubuntu WiFi connection is not stable (WiFi cannot connect problem)