Does the system in fact have a WWAN card (they're not standard equipment, but rather optional when the system is configured)?  Without a WWAN card, the SIM card is useless. You can either look inside the system for the presence or absence of the card, or look up the as-shipped specifications at support.dell.com (use the service tag).    
Hi experts,   My Dell Latitude 5511 comes with a SIM Card slot and I am planning to travel and the internet via mobile sim card will help. I inserted a SIM card into the slot after shutting down, but nothing seem to happen. I tried updating BIOS and other seemingly related drivers from  [URL] Also tried a program Dell Mobile Broadband Manager but it shows "The Mobile broadband device is not communicating" I checked BIOS settings and couldn't find a feature to enable/disable the WWAN/4g/Cellular modem although there are others to enable/disable the integrated MicroSD card reader which sits next to the SIM card slot. Windows 10 Device Manager doesn't show network hardware that I can relate to the 4g modem.   Any advice on how to use the SIM card slot on this laptop?  
Latitude 5511 Sim card slot