Hello Linux Users.

In this article i will show you how to fix the slow connection problem when using wifi on Ubuntu 13.04 Raring Ringtail, Ubuntu 12.04 Precise Pangolin or Linux Mint 13 Maya.
Method 1:
$ sudo su
# echo "options ath9k nohwcrypt=1" >> /etc/modprobe.d/ath9k.conf
Reboot and check if the problem is fixed. If this did not help, try doing the things listed in the second method.
Method 2:
This method forces iwlagn to not use n. The settings are not persistent, if you notice that the wifi connection works better, make this permanent.
$ sudo rmmod -f iwlagn
$ sudo modprobe iwlagn 11n_disable=1
If this improved your wifi connection, do this to make things persistent:
$ sudo su
# echo "options iwlagn 11n_disable=1" >> /etc/modprobe.d/iwlagn-disable11n.conf
If this trick did not help also, go to method 3.
Method 3:
Deactivate IPv6 support:
$ sudo su
# echo "#disable ipv6" >> /etc/sysctl.conf
# echo "net.ipv6.conf.all.disable_ipv6 = 1" >> /etc/sysctl.conf
# echo "net.ipv6.conf.default.disable_ipv6 = 1" >> /etc/sysctl.conf
# echo "net.ipv6.conf.lo.disable_ipv6 = 1" >> /etc/sysctl.conf