The cycling between connected and disconnected is a common problem with atheros wi-fi card and the acer_wmi module. If you have an Acer laptop with an Atheros wireless card, you should read this article, just in case.

To repair the cycle between connected and disconnected on an Acer Aspire 5733Z-4851, or other Acer Aspire laptop with Atheros Wifi, blacklist the acer_wmi module:
$ echo blacklist acer-wmi | sudo tee /etc/modprobe.d/blacklist-acer-wmi
Next, unload the acer-wmi module:
$ sudo rmmod acer-wmi
The first command adds the acer-wmi module to blacklist, so it is not loaded at the next reboot, and the second command unloads the module instantly.