According to insider information, Apple recently actively cooperates with Intel to create 5G-chips for future iPhone. Note that it was previously reported that Apple would refuse to cooperate with Snapdragon in favor of Intel for the production of chips for the iPhone and iPad in 2018.
Intel is working on 5G modems for the iPhone

Although at this stage Intel is behind Snapdragon in the development of 5G-modems, soon the situation will change. The same source said that several thousand people are engaged in Intel's research. At the same time for Intel, the most important thing is that the final product should be delivered for iPhone. In this case, we are talking about the models of 2019 or even 2020.
Recall that 5G-network will be able to provide data transfer rates up to 1 Gbit / s. However, the transition to a new communication standard by itself is rather complicated and requires coordination between operators and smartphone manufacturers.