There is a lot of technical information about getting d-link to work with 3G,4G, and LTE. Before worrying about all this read below.
If your phone app ( IO7) is using d-link lite and you can not get it to connect on 3G,4G, or LTE services from the phone company make sure you DID NOT turn off cellular Data in - "Settings" "Cellular " "My D-link Lite" OR go to "Settings" "My D-Link Lite" and turn cellular data on there..
Hope this helps...