Performance Analysis of Preemption-Based Call Admission Scheme for Macrocell Users in Multi-Operator LTE Picocellular–Macrocellular Networks

Abstract

A heterogeneous network (HetNet) is one of the core features that have been introduced in the LTE-advanced standardization to meet the predicted requirements for higher data rates and capacity. An integrated picocellular–macrocellular networks is part of such HetNets. Most previous works have concentrated on solving the picocellular–macrocellular networks challenges, including optimal picocell deployment, interference coordination, cell association methods and frequency resource allocations. However, the resource allocation control issue for LTE macrocells integrated with underlying picocells owned by different operators that can allow macrocell user (MU) accommodation has not been investigated deeply. Therefore, this paper proposes and analyzes a new resource allocation control framework called a preemption-based call admission control scheme (PCAC) for integrating independent underlying picocells with macrocell networks. The proposed scheme aims to utilize the resource blocks (RBs) of picocells efficiently to improve MU performance by allowing its MU visitors to utilize unused picocell RBs without any degradation for picocell users. A developed simulation model and a multi-dimensional continuous-time Markov chain (CTMC) model are used to model and analyze the proposed PCAC. The analytical model developed considers a limited-size buffer to store MUs, buffer time out and resource reservation. The MU connection-level performance metrics, including dropping and blocking probabilities, are derived and studied. The results indicate that better connection-level parameters for MUs and higher throughputs are achieved by using the proposed PCAC.