Core Definition as a premise of 5G in conceptual terms

I am Ph.D. Candidate at the State University of Campinas (UNICAMP), with a 5G topic research. I would like to ask a technical but also theoretical question. The 5G concept, whereas a relational variable (5G+X), depends on the Core definition from a theoretical perspective. How would be this definition in 5G terms? What do you think about this topic? Do you agree 5G is 5G+X, or do you have a better formulation?

Thank you in advance,
Best Regards.