Hi Avelinov,
I have checked the Service tag which is for Inspiron 5521 as per our data base and its shown as a different system at support site. I will contact the respective team to get that corrected.
Regarding the Wireless card, I see that the system was shipped with Intel Centrino Advanced-N 2230. Refer the following link to download the drivers: http://dell.to/10nl70k
Please try installing the drivers and let me know how it goes.