What is the GSM-sim slot beneathe the d630 used for?

"The D620/630 series had an option where you can purchase an internal mobile broadband data card. Like the iPad has a ""Cellular"" version where you can insert a sim and use data, the D620 has the same capability if you have this card. Please note, the Dell card is Carrier Specific (AT&T, T-Mobile, Sprint, Verizon have their own and are not interchangeable).

Here's a video on what it looks like in the laptop.

https://www.youtube.com/watch?v=6yaZXxNy...

Ebay sells this:

http://www.ebay.com/itm/DELL-Latitude-D4..."

"I found an option in the bios for sim cards that is factory defaulted to off, I have not got a chance to test it yet but I hope this works for you!

~Will"

My dell 630 computer isn't working sim card and I want to get the gsm for my computer

my laptop sim looked