Enhanced Adaptive Call Admission Control Scheme with Bandwidth Reservation for LTE Networks

Abstract

Call admission control (CAC) is one of the radio resource management techniques that regulate resources for new or ongoing calls in a network. The existing CAC schemes waste bandwidth, due to their failure to check for the effect of degradation before degrading admitted RT calls and the schemes increases the call dropping probability (CDP) and calling blocking probability (CBP) of RT calls due to the delay incurred when bandwidth is degraded from the admitted RT calls. This paper proposed an enhanced adaptive call admission control (EA-CAC) scheme with bandwidth reservation. The scheme employs a prior-check mechanism that ensures bandwidth to be degraded will be enough to admit the new call request. It further incorporates an adaptive degradation mechanism that degrades NRT calls before degrading the RT calls. The performance of the EA-CAC scheme was evaluated against that of Adaptive Call Admission Control (ACAC) and QoS-Aware Call Admission Control (QA-CAC) schemes using the Vienna LTE system-level simulator. The EA-CAC scheme exhibits better performance compared to the two schemes in terms of throughput, CBP, and CDP of RT calls without sacrificing the performance of NRT calls.