i'm using a dell laptop the wifi turns off automatically after some time
and only if i restart the machine it work this happens very often

I have already tried the MTU method it is in automatic
and this problem happens in both college(proxy) and home networks(no proxy)

And deleting the connections from the menu and turning off and on the wifi doesnt work is there any permanent solution for this

    *-network

   description: Wireless interface

   product: Centrino Wireless-N 2230

   vendor: Intel Corporation

   physical id: 0

   bus info: pci@0000:08:00.0

   logical name: wlan0

   version: c4

   serial: 68:5d:43:5e:b1:f9

   width: 64 bits

   clock: 33MHz

   capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless

   configuration: broadcast=yes driver=iwlwifi driverversion=3.8.0-19-generic firmware=18.168.6.1 ip=192.168.40.202 latency=0 link=yes multicast=yes wireless=IEEE 802.11bgn

   resources: irq:45 memory:c1500000-c1501fff