Abstract:
Call admission control (CAC) is one of the radio resource management (RRM) techniques that regulates and provide resources for new call requests or active call requests in the network. The existing call admission control schemes waste bandwidth due to its failure to check whether the degraded bandwidth will be enough to admit the new call requests. It also increases the call dropping probability (CDP) and calling blocking probability (CBP) of real time calls as a result of the delay incurred when bandwidth is degraded from the admitted real time (RT) calls. In this study, an Enhanced Adaptive Call Admission Control (EA-CAC) scheme with bandwidth reservation was proposed. The scheme proposed a prior-check mechanism which ensures bandwidth to be degraded will be enough to admit the new call request. It further incorporates an adaptive degradation mechanism which will degrade non-real time (NRT) calls first before degrading the RT calls, this also ensure that all admitted calls are not degraded below their minimum bandwidth requirement. The performance of the proposed scheme was evaluated against the benchmark scheme using different performance metrics. The EA-CAC increases the throughput of RT calls by 25% and also reduces the CBP and CDP by 12.2% and 15.2% respectively. The scheme performed better than the benchmark scheme in terms of throughput, CBP and CDP of RT calls without sacrificing the performance of the NRT calls.
