Uplink Modeling of $K$ -Tier Heterogeneous Networks: A Queuing Theory Approach

Heterogeneous networks (HetNets) are expected to release enormous capacity beyond what is achievable now. This comes at the price of higher interference that may jeopardize proper network operation if not managed cautiously. In handling this problem, mathematical modeling of HetNets to understand their underlying facts is necessary. As the mathematical theory of waiting lines, queuing theory is exploited in this paper as a powerful tool to model the uplink transmission of a user equipment (UE) in a K-tier HetNet, as an M/G/1 queue with interruption operating at the packet level. By integrating key findings on HetNets (using stochastic geometry) into the queue, a realistic model is obtained. This model enables us to understand what a UE experiences in terms of throughput, an angle that has barely been looked through by others. The modeling framework considers all the essential HetNet parameters, including the transmit power, spatial distribution, service rate, traffic flow intensity, and base station coverage threshold, to obtain the probability generating function and related statistics of the UE queue length.