Multi-link propagation modeling for beyond next generation wireless

In this review paper, a number of recent contributions in the field of multi-link propagation are presented and analyzed, with a particular focus on beyond next generation wireless communication networks. Advances in channel sounding, characterization and modeling are described in three areas: (i) regarding cooperative channel fading statistics, the impact of node mobility is highlighted; (ii) metrics for characterizing the separation between multiple single- and/or multi-antenna channels are detailed; (iii) new geometry-based approaches with multi-link capabilities, including WINNER and COST models, are presented and compared. Finally, a couple of key features not sufficiently included in current models are discussed.