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 regulates and provide resources for new or ongoing calls in the network. The existing CAC schemes wastes bandwidth due to its failure to check before degrading admitted real-time calls and it also increases the call dropping probability (CBP) and calling blocking probability (CBP) of real-time calls due to the delay incurred when bandwidth is degraded from them. This paper proposed an enhanced adaptive call admission control (EA-CAC) scheme with bandwidth reservation. The scheme employs a prior-check mechanism that ensured bandwidth to be degraded will be enough to admit the new call request. It further incorporates an adaptive degradation mechanism that degrades non-real time calls before degrading the RT calls. The performance of the EA-CAC scheme was evaluated against two existing schemes using 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.

Performance Evaluation of Call Admission Control Schemes in 3GPP Long Term Evolution Networks

“…Enhanced Adaptive CAC scheme with bandwidth reservation was proposed in [1]. The EA-CAC scheme was aimed at improving the QoS of all admitted calls thereby increasing the throughput of the overall system without degrading the performance of NRT calls as it has been happening in the previous schemes.…”

“…BCAC doesn't take into cognizance different traffic types and as such it cannot be applied in today's network which has diverse applications or traffic types. In this paper, we are considering the schemes proposed in [1], [2] and [10]. Fig.…”

“…2 shows the diagrammatic description of the scheme proposed in [10] which is Adaptive Call Admission Control (ACAC) with Bandwidth reservation. The pseudo-code for algorithm proposed in [1] and [2] are also presented in this section.…”

“…Hence, EA-CAC was proposed in [1] to overcome the challenges of the QA-CAC. The scheme works in a similar way with the QA-CAC but has some improvements by introducing a prior-checking mechanism and also an adaptive degradation procedure all with the aim of improving the performance of the QA-CAC.…”

“…Therefore, achieving speedy delivery of data to satisfy user needs requires improvement of quality of Service (QoS). Long Term Evolution (LTE) was one of the technologies proposed by the Third Generation Partnership Project (3GPP) as a promising wireless technology that will cater for the high demands of mobile users by supporting a number of diverse applications [1]. The main objective of LTE is to deliver high data rates for bandwidth-demanding applications such as; live streaming, high speed download and upload, as well as improving the spectral efficiency of the network [2].…”