Back in June, there were reports of Intel getting orders from Apple for modem chips that would be used for various wireless connectivity which would go into AT&T variants as well as some other versions of the new iPhone 7.
Chipworks performed a teardown of the iPhone7 which did not stop at just taking the unit apart. The teardown goes even further into the specific chips used in the A1778 iPhone 7 model which they have gotten their hands on. This model is used on AT&T or T-Mobile and other GSM networks. Its not known (but likely) that the CDMA variants connecting to Sprint or Verizon stuck to Qualcomm for their modems.
An entire mobile cellular platform was found in the iPhone 7 including a modem (with model number XMM7360), two RF transceivers, and a power management integrated circuit. If you wish to get into the nitty gritty of the chips and their descriptions, you can head over to the source link below.
Chipworks says it will get a Verizon unit and confirm whether or not the CDMA variant also makes use of these Intel chips.
Source | Via