Potential throughput in 3D ultradense cellular networks

We consider a three dimensional (3D) ultradense urban cellular network where the base stations (BSs) are stacked vertically as well as extending infinitely in the horizontal plane. We use a dual-slope path-loss model where different path-loss exponents are used for distances less and greater than a corner distance R_c. We derive the scaling laws for coverage probability and potential throughput for 3D case, and prove that if the path- loss exponent α₀ for the region inside R_c (termed as close-in region) is less than 3, then the SINR eventually decays to zero. We also show that the potential (i.e. best case) aggregate throughput decays to zero for α₀ <; 1.5. We also consider a case where user density is kept fixed and show that potential throughput saturates as BSs becomes ultradense in this case.