A Comparison of the Performance of Two-Tier Cellular Networks Based on Queuing Handoff Calls

Two-tier cellular networks provide an enhanced use of the networks' resources for both high and low speed users. However, they cause an increase in the number of handoffs between cells due to having smaller cell sizes in the microcell tier. An effective approach used to prevent the dropping of ongoing calls in a network is delaying these calls in a queue until a channel becomes available. In this paper, we propose a new Markov model for a two-tier cellular network having a FIFO queue in the microcell tier. The performance of the model is then compared with those of a previously proposed model having a queue in the macrocell tier and the effect of having a queue in the microcell or macrocell on both high and low speed users is observed. Keywords—Blocking probability, FIFO queue, Markov chains, Two-tier cellular networks.