Adaptive Call Admission Control Scheme Research Articles

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

Radio resource management (RRM) techniques are employed for resource utilization in wireless broadband networks. One of the major RRM techniques that are aimed at controlling the admission and rejection of new or handoff calls/connections in a network is known as Call Admission Control (CAC). CAC accepts or rejects a connection request based on a certain pre-determined criterion(s). Performance Evaluation of some existing CAC schemes was presented in this paper. The schemes evaluated are; Adaptive Call Admission Control Scheme with Bandwidth reservation termed as (ACAC), QoS-Aware Call Admission Control Scheme termed as (QA-CAC) and Enhanced Adaptive Call Admission Control Scheme with bandwidth reservation termed (EA-CAC). Vienna LTE system level simulator was used for the simulation experiments conducted. After several experiments, the results show that the QA-CAC and EA-CAC schemes perform better in terms of increasing the throughput of real-time (RT) traffic while all the three schemes almost have the same performance in terms of admitting the non-real-time (NRT) traffic.

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

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.

An Adaptive Call Admission Control Scheme for Overflowed Traffic with Buffering of Data/New Voice Calls in Multilayer 3G Wireless Mobile Networks

An Adaptive Call Admission Control Scheme for Overflowed Traffic with Buffering of Data/New Voice Calls in Multilayer 3G Wireless Mobile Networks

Adaptive call admission control scheme with optimal resource allocation for multi-class cellular networks

There exists an increasing demand by an ever-growing number of mobile customers for transfer of rich media contents such as video conferencing, file transfer and retrieval service, e-mail, paging, fax in addition to simple voice calls. This requires very high bandwidth that cannot be provided by the current cellular systems maintaining quality of service (QoS) because of limited bandwidth capacity. In this paper, a new adaptive call admission control scheme is proposed for allocating bandwidth optimally as well as provisioning QoS to the mobile users so far as practicable. In addition to these services, the proposed scheme during congestion also attempts to maximise the number of served calls in a cell to satisfy maximum number of users. Extensive simulation results show that the proposed scheme outperforms the existing schemes in terms of call blocking probability, system delay and bandwidth utilisation.

Adaptive call admission control in 3GPP LTE networks

SUMMARYIn this article, we propose new methods to reduce the handoff blocking probability in the 3rd Generation Partnership Project Long Term Evolution wireless networks. This reduction is based on an adaptive call admission control scheme that provides QoS guarantees and gives the priority of handoff call over new call in admission. The performance results of the proposed schemes are compared with other competing methods using simulation analysis. Simulation results show the major impact on the performance of the 3rd Generation Partnership Project Long Term Evolution network, which is reflected in increased resource utilization ratio to (99%) and in the ability in satisfying the requirements of QoS in terms of call blocking probability (less than 0.0628 for Voice over IP service) and dropping probability rate (less than 0.0558).Copyright © 2012 John Wiley & Sons, Ltd.

Adaptive call admission control scheme for heterogeneous overlay networks

Any future heterogeneous overlay network system must be able to support ubiquitous access across multiple wireless networks. To coordinate these diverse network environments, one challenging task is a call admission decision among different types of network. In this paper, we propose a new call admission control scheme to provide quality of service (QoS) while ensuring system efficiency. Based on the interplay between network structure and dynamics, we estimate the network's QoS level and adjust the service price adaptively with the aim of maximizing the network performance. A simulation shows that the proposed scheme can approximate an optimized solution while ensuring a well-balanced network performance in widely different network environments.

Hybrid Adaptive Call Admission Control Mechanism for Ensuring QoS in 3GPP: LTE Networks

Third Generation Partnership Project (3GPP) Long Term Evolution (LTE) system is targeted to efficiently guarantee the quality of service (QoS) of services such as audio/video streaming, gaming and Voice over IP (VoIP). So the system resource allocation should obtain the multiuser diversity gain making full use of the channel condition, and take the quality of service (QoS) of different services into account. Due to the heavy user’s space and limited Resource Block (RBs), it is infeasible to guarantee all ongoing users' QoS. Then, some call are blocked and lost. The proposed method reduces the handoff blocking probability in LTE wireless networks. Hybrid Adaptive call admission control scheme performs the QoS operation based on the priority at the time of call admission. This method reduces new call blocking probability.

A Soft Computing Based Adaptive Call Admission Control Scheme for Bi-Class Traffic in CDMA Cellular Network

Soft handoff in CDMA cellular system increases system capacity as compared to hard handoff as interference is reduced by transmitting signals as lower power level. A CDMA cellular system involving voice and data calls is considered in this paper. The model proposed in this paper is for data and voice services (Bi-class). It is based on reservation for handoff voice and data calls along with call queuing scheme for handoff data calls. Preemptive priority scheme is used for handoff voice calls over ongoing data calls. Upper channel limits are set for new voice as well as data calls to give priority to handoff calls. For better resource management and efficient call admission to originating and handoff calls, Neuro-fuzzy call admission controller is designed. This controller uses the adaptable feature of soft handoff threshold parameters to accommodate important voice and data calls. The proposed ASNFC controller is compared with the two variants of Bi-class CAC scheme. General Terms Call Admission Control, Soft Computing

Bandwidth borrowing-based QoS approach for adaptive call admission control in multiclass traffic wireless cellular networks

SUMMARY This paper proposes a QoS approach for an adaptive call admission control (CAC) scheme for multiclass service wireless cellular networks. The QoS of the proposed CAC scheme is achieved through call bandwidth borrowing and call preemption techniques according to the priorities of the traffic classes, using complete sharing of the available bandwidth. The CAC scheme maintains QoS in each class to avoid performance deterioration through mechanisms for call bandwidth degradation, and call bandwidth upgrading based on min–max and max–min policies for fair resource deallocation and reallocation, respectively. The proposed adaptive CAC scheme utilizes a measurement-based online monitoring approach of the system performance, and a prediction model to determine the amount of bandwidth to be borrowed from calls, or the amount of bandwidth to be returned to calls. The simulation-based performance evaluation of the proposed adaptive CAC scheme shows the strength and effectiveness of our proposed scheme. Copyright © 2011 John Wiley & Sons, Ltd.

A Bandwidth Efficient Adaptive Call Admission Control Scheme for QoS Provisioning in IEEE 802.16e Mobile Networks

In wireless environment the bandwidth resource is limited and therefore judicious use of the available resources is needed. A bandwidth efficient Call Admission Control (CAC) is proposed in this paper for quality of service (QoS) provisioning for the services defined in IEEE 802.16e mobile WiMAX standards to satisfy both bandwidth and delay guarantees to the admitted connections. The concept of adaptive bandwidth degradation is introduced to improve the bandwidth utilization (BU) of the system. The proposed CAC scheme is analyzed by Markov Chain model and performance evaluation is made in comparison with fixed step size degradation. Results show that the proposed adaptive CAC scheme has excellent BU under stressed network condition. Also the long term average revenue is calculated for different service flows and for the overall system to see the efficiency of the adaptive CAC scheme.

Models for Call Acceptance Based on Handoff Guarantees

Call admission control (CAC) is important for cellular wireless networks to provide quality-of-service (QoS) requirements to users. Static and adaptive CAC schemes, respectively, make unrealistic assumptions about the distributions of the handoff call arrival process and the number of users in a cell. Handoff arrivals are usually assumed to follow Poisson process in static CAC schemes for Poisson new call arrivals and exponentially distributed call holding and cell residence times. We use a simple proof to show that this assumption of Poisson handoff arrival process is not justified for a two-cell wireless network. In general, we find that the handoff process can be captured by a two-dimensional Markov chain. We propose a novel adaptive CAC scheme for the two-cell system which accepts a new call if it can guarantee, with a certain probability, that a user's call will be maintained irrespective of its (his/her) movement in the system. Then, we extend this adaptive scheme for multiple-cell network. We develop another variant of this adaptive scheme which we call fractional adaptive scheme. Both the adaptive and fractional adaptive schemes are found to outperform the guard channel scheme in controlling the handoff failure probability in a cellular wireless network.