Does a technical definition of 5G even exist? Going from 3 to 4G was mostly about the transition from CDMA to ODFMA with other perks tacked on. This is why eve

Does a technical definition of 5G even exist? Going from 3 to 4G was mostly about the transition from CDMA to ODFMA with other perks tacked on. This is why even though the marketing department at AT&T called HSPA+ "4G" the engineers knew it really wasn't. What is the equivalent step change for 5G that is as significant as OFDMA, or is 5G is purely a collection of incremental improvements?