A new approach that combines physical and link layers is introduced to estimate the performance of wireless systems that support ultra-reliable low-latency communications (URLLC). Motivated by ultra-dense deployment in next-generation networks, the effects of spatial diversity of multiple base stations are investigated with analytical expressions for evaluating signal-to-noise-and-interference-ratio (SINR) coverage probability at physical layers and the average blocking probabilitiy at link layers. The impact of network densification on the blocking probability, which is of practical interest to carriers, is studied with numerical results. Specifically, considering the second cell to exploit the spatial diversity of multiple cells offers an order of magnitude improvement in the average blocking probability. Numerical results also show that SINR coverage and average blocking probabilities achieve optimal values at different cell sizes at either the first station or two stations. The proposed approach can be generalized to utilizing more than two cells through a recursive process.