CentOS 6 / SL 6 / RHEL 6 How to change wireless standard

1.create a file called /etc/modprobe.d/iwlwifi.conf with a single line like this:

options iwlwifi 11n_disable=1

2. Reboot (or "modprobe -r iwlwifi ; modprobe iwlwifi" as root).

This can help in case of problem with iwlwifi driver / card.
 

Found on:  https://bugzilla.redhat.com/show_bug.cgi?id=785239