A Dynamic Call Admission Control Scheme and Performance Modeling for 4G LTE Networks

Abstract

There is an exponential increase in the number of high bandwidth and quality demanding users that has forced cellular service providers to offer better quality of service (QoS). In long term evolution (LTE) also called 4G networks, the number of service classes have been increased and call admission control (CAC) strategies are implemented to fulfill the QoS requirements. CAC schemes based on bandwidth reservation, bandwidth degradation and preemption have been proposed with the aim of better utilization of network resources. However, in heterogeneous network environment, high priority traffic classes sometimes demand complete protection and very efficient and dynamic call admission control (CAC) strategies are still required to guarantee quality of service while achieving better utilization of network resources. A dynamic CAC is proposed in this work with the aim to provide complete protection to high priority traffic. A combined usage threshold and total preemption mechanism have been introduced guarantying complete protection and improved quality of service for high priority traffic class. Markov chains have been used to evaluate the proposed CAC scheme along with necessary simulations for validation. Results show that the proposed CAC scheme significantly improves call dropping probability of high priority traffic, without much penalizing the low priority traffic. Numerical results imitate the experimental results with insignificant differences.