Disaggregation for Energy Efficient Fog in Future 6G Networks

We study the benefits of adopting server disaggregation in the fog computing tier by evaluating energy efficient placement of interactive apps in a future (6G) fog network. Using a mixed integer linear programming (MILP) model, we compare the adoption of traditional server (TS) and disaggregated server (DS) architectures in a fog network that comprises selected fog sites. We also propose a heuristic for energy efficient and delay aware placement of interactive fog apps in a fog network which effectively mimics the MILP model formulated in this paper. Compared to a non-federated fog computing layer, federation of selected fog computing sites over the metro-access network enables significant reductions of the total fog computing power consumption (TFPC). Relative to the use of TSs in the fog network, the adoption of DSs improves the energy efficiency of the fog network and enables up to 18% reduction in TFPC. To minimize response time, more instances of interactive fog apps are provisioned in a fog network that is implemented over a network topology with high delay penalty. Our result also shows that the proximity of metro-central offices and radio cell sites to geo-distributed users makes them important fog sites for provisioning delay-sensitive fog applications.