Thank you for writing to the Dell Community Forum.
The wireless cards tested on the system by Dell are, Dell Wireless 1704 and Bluetooth 4.0 and Dell Wireless 1705 and Bluetooth 4.0 with half-height mini-cards only. You can also get a USB wireless adapter, refer to this link http://dell.to/2tyOBh3. You can even get a PCIe x1 wireless card.
Kindly get back if there are any further queries.
For me to better assist in troubleshooting, please click my DELL-username and send me a Private Message with the Dell Service Tag number and your email address.