Wirelles disappear on XPS 13 (L321X)

Hello.

Today I have been working on my XPS 13 (L321X) and I nottice a couple of times that my wireless didn´t detect the available wireless at the office, then I restart it 2 times and again it starts getting the wifi.

But then I go out and the computer goes to hibernation, when retur and restart the computer the wireless  isn´t getting the wifi net and the wireless simbol isn´t appearing in the status bar. I restart a couple of times, and no ressult, I use the diagnossis tool here:

http://www.dell.com/support/home/us/en/19/product-support/servicetag/HVBDRS1/diagnose?s=BSD

And everything seems weel. I try pressing the Fn F2 button and nothing happend.

What else can I do?

Where is the problem? Now I´m connected to the net cable, and this didn´t work to me because I´m moving freccuently.

Thanks for your help