I'm trying to improve my Facetime video call sessions between my Macbook and an iPhone. It seems there's some delay/latency. What can be done to improve the quality of the call/connection? Is 4G is the fastest/best speed available for a Facetime call? Do you think having a personal hotspot device would help improve the quality of a Facetime call from (or to) my Macbook, from an iPhone? Is a Cellular Data Plan(ATT) diffrent than wi-fi? Can Facebook run on either? Would the Cellular Data plan be better for this type of video connection? Thanks again for your insight. much appreciated.