“…The rest of the papers (i.e., 87%) do not follow this principle. Either they are implemented as centralised architectures [2,10,14,23,43,47,49,56,57,67,81,98,105,106,112,116], or federated architectures where there are no interactions between nodes at the same layer (e.g., servers at the edge layer) [8,9,16,29,31,36,48,55,58,62,66,75,83,86,99,[101][102][103].…”