I have the exact same computer and wifi card (and Dlink DIR-855 access point) and I found this discussion:
<http://ubuntuforums.org/showthread.php?t=1605338>
I applied the discussed workaround and rebooted:
:/etc/modprobe.d$ cat intel-5300-iwlagn-disable11n.conf options iwlagn 11n_disable=1
This seems to have solved the problem, no wifi problem for 75 minutes yet anyway.
I have the exact same computer and wifi card (and Dlink DIR-855 access point) and I found this discussion:
<http:// ubuntuforums. org/showthread. php?t=1605338>
I applied the discussed workaround and rebooted:
:/etc/modprobe.d$ cat intel-5300- iwlagn- disable11n. conf
options iwlagn 11n_disable=1
This seems to have solved the problem, no wifi problem for 75 minutes yet anyway.