Call Admission Control Scheme Research Articles

Performance evaluation of lifetime‐driven admission control for infrastructure‐less clustered wireless networks

SUMMARYClassical call admission control schemes focus on QoS enhancements because radio bandwidth will be allocated for mobile communications. Both of radio bandwidth and lifetime duration of mobile node are very important and precious for resources allocation in wireless networks. In this paper, we present a novel admission control for infrastructure‐less clustered wireless networks. The proposed admission control is based on QoS constraints and the lifetime duration of mobile nodes, including speed and power consumption parameters. Some new schemes are introduced, QoS parameters are negotiated during the admission procedure, and a forced handover technique is developed instead of reject flows, using a centralized view of topology. The performance of the proposed scheme was analyzed and evaluated with respect to throughput and call blocking probability, using different classes of traffic. Furthermore, simulation results confirmed the effectiveness of the admission control schemes. Copyright © 2011 John Wiley & Sons, Ltd.

A metamodeling approach for cross-layer optimization: A framework and application to Voice over WiFi

Cross-layer design has been proposed to optimize the performance of networks by exploiting the interrelations among parameters and procedures at different levels of the protocol stack. This paper introduces a quantitative framework for the study of cross-layer interactions, which enables design engineers to analyze and quantify interlayer dependencies and to identify the optimal operating point of the system, by using network economic theory principles. The framework is then used for performance optimization of a single-cell Voice over WiFi (VoWiFi) system. Insights gained from the considered scenario enable us to define a novel cross-layer Call Admission Control (CAC) scheme. The multistage CAC takes into account Quality of Service (QoS) criteria, which provide satisfaction to the end user, as well as revenue criteria that maximize the possible profit of the WiFi provider.

Multidimensional Erlang model with randomized call admission control strategy and its application in communication networks

An analytical method is proposed for the analysis of a multidimensional Erlang model with randomized call admission control strategy. The applications of this model in both wireless multiservice cellular networks and integrated voice/data networks are demonstrated.

Cooperative Game Theory-Based CAC Strategy for Mobile Communication Systems

由于无线频谱是极为有限的资源,呼叫接纳控制(call admission control,简称CAC)成为移动通信系统中无线资源管理的一个重要部分.针对流媒体对接入资源的过度占用问题,提出了一种基于合作博弈理论的CAC 策略,博弈方是处于服务状态的业务和申请接入的新业务,基站是保证协议强制执行的外在力量,基站选择效用和最大的策略组作为博弈过程的最终结果.仿真结果表明,所提策略有效缓解了流媒体业务对资源的捕获效应,保证了用户接入的公平性,对于实际系统性能的改善具有重要的意义.;Since the radio spectrum is a very scarce resource, the call admission control (CAC) is one of the most important parts in radio resource management of mobile communication systems. With the aim at resolving the problem of streaming a medium’s over-use of resource, a cooperative game theory-based CAC strategy is proposed in this paper. The players are the services in connection, and a new service requests to access the system. The base station is the external power, which ensures the protocol operation. The results show that the capture effect of resource caused by streaming media is eased by adopting the CAC strategy; therefore, the access fairness is guaranteed. It is very significant to improve the performance of practical system applications.

LTE-WLAN 이종 네트워크 환경에서 자원예약률 변화에 따른 통합 호 수락 제어의 성능분석

본 논문에서는 LTE와 WLAN이 존재하는 이종 네트워크 환경에서 네트워크 선택과 자원 예약 기반의 호 수락 제어 기법을 결합한 통합 호 수락 제어 기법을 제시하고 성능을 분석한다. 이를 위해 LTE 와 WLAN이 중첩된 네트워크 환경에서 단말이 네트워크를 선택할 때의 네트워크 결정률과 자원예약기법이 적용된 통합 호 수락 제어시스템을 제안하고 마코프 체인(Markov Chain) 모델링을 통해 제안된 시스템의 성능을 분석한다. 본 논문에서는 성능지표로서 LTE와 WLAN 각 네트워크 신규호 차단률(New call Blocking Probability), 핸드오프호의 절단률(Handoff call droppng Probability), RB 사용률(Resource Block utilization)을 사용한다. 본 논문의 분석결과로서 통합 호 수락 제어 기법을 적용한 시스템이 적용되지 않은 시스템에 비해 나은 성능을 보였고, 통함 호 수락 제어 기법을 적용할 경우에는 전체의 10%를 자원예약비율로 선택하는 것이 적합함을 보였다. 본 논문의 결과는 향후 LTE와 WLAN의 중첩된 네트워크 환경에서 자원예약기법이 적용된 통합 호 수락 제어 시스템 도입 시에 참고할 만한 자원예약률의 가이드라인을 제시할 수 있을 것이다. In this paper, we analyze and propose the Joint Call Admission Control(JCAC) scheme to combine network selection scheme and radio resource reservation based Call Admission Control(CAC) in LTE-WLAN heterogeneous networks. First, We propose the JCAC system that uses network decision rate to select a network for terminal and radio resource reservation scheme in overlaying LTE-WLAN network environment. And we analyze the performance of a proposed system using markov chain model. The performance is presented in terms of the new call blocking probability, handoff call dropping probability, and channel utilization of each network. As a performance result of the our research, the system using JCAC is better than the system using non-JCAC. We found a suitable resource reservation rate that is 10% in the system using JCAC. Our work may be useful as a guideline of resource reservation rate to introduce JCAC system using resource reservation scheme in overlaying LTE-WLAN network environment.

Endpoint-Based Call Admission Control and Resource Management for VoWLAN

This paper examines two specific aspects of resource management in Wireless Local Area Networks (WLANs)-Call Admission Control (CAC) and handling of Link Adaptation (LA) events. A self-consistent system to manage these for Voice over Internet Protocol (VoIP) over an IEEE 802.11 WLAN is presented. The proposed CAC scheme is based on the Endpoint Admission Control (EAC) paradigm, where the endpoints probe the network to determine if the call can be supported with acceptable Quality of Service (QoS). The proposed scheme was evaluated on an experimental testbed and test results show that correct admission decisions were made under various network configurations. The scheme also determines if LA has resulted in the system becoming congested and, if so, the voice codec of the handset which has undergone LA is adapted so as to restore the system to its earlier state, thereby alleviating the congestion. The proposed scheme was evaluated on the experimental testbed and test results show that the codec adaptation scheme was very effective at overcoming the effects of LA for VoIP over WLAN.

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.

A Novel Optimization Scheme Based on QoS in Wireless Networks

There has been explosive demand for supporting multi-class traffic, especially bandwidth-intensive multimedia traffic in wireless networks. The ability to manage bandwidth to cope with wireless network resource fluctuations is becoming increasingly important. In this paper, we propose an efficient Call Admission Control (CAC) scheme that relies on adaptive and dynamic resource reservation strategy for multi-class service wireless networks. Extensive simulation experiments have been conducted to evaluate the performance of the proposed scheme. Results show that our proposed adaptive scheme is effective in guaranteeing QoS requirements by keeping the call blocking and handoff dropping probabilities substantially low.

Dynamic Preemption Call Admission Control Scheme Based on Markov Decision Process in Traffic Groomed Optical Networks

In optical grooming networks, the capacity fairness issue can be resolved by utilizing a call admission control (CAC) mechanism. Existing CAC schemes are generally based on one of four different techniques, namely, static bandwidth reservation, static threshold setting, mathematical statistics, and Markov decision processing without buffer implementation (NB). However, irrespective of the technique used, a trade-off exists between the network fairness and the network throughput. In our previous work, a conditional-preemption CAC (CP-CAC) mechanism was proposed to increase the network throughput while simultaneously maintaining the fairness. However, a CP-CAC mechanism considers only the blocking probability at particular instants of preemption. This paper proposes the use of a dynamic-preemption call admission control scheme (DP-CAC) to decide whether or not to preempt existing requests based on the optimal policy derived from a Markov decision process. Similar to CP-CAC, the DP-CAC method is also based on a dynamic threshold setting concept and is implemented using a single connection buffer and an associated set of virtual indicators. The simulation results show that compared to the CP-CAC mechanism, the proposed DP-CAC further improves the network throughput without sacrificing the fairness. Additionally, the average waiting time induced by the buffer implementation for DP-CAC is just 0.23 time units shorter compared to 0.25 for CP-CAC. Finally, it is shown that the proposed method also ensures fairness in a variety of common network topologies including 6 × 6mesh-torus, NSF, and Cost239.

A Fairness-Based Greedy Call Admission Control Strategy with Non-uniform Traffic Distribution in CDMA Systems

A Fairness-Based Greedy Call Admission Control Strategy with Non-uniform Traffic Distribution in CDMA Systems

MANET QoS support without reservations

AbstractAn inelastic flow is a flow with an inelastic rate, i.e., the rate is fixed, and it cannot be dynamically adjusted to traffic and load condition as in elastic flows like TCP. Real time, interactive sessions, and video/audio streaming are typical examples of inelastic flows. Reliable support of inelastic flows in wireless ad hoc networks is extremely challenging because flows and routes dynamically change and flows compete for the shared wireless channel. Bandwidth must be reserved for inelastic flows at session set up time. To avoid repeated attempts to set up reservations in a ‘volatile’ network and prevent serious network capacity degradation due to call set up overhead, a Call Admission Control strategy robust to mobility must be developed. In this paper we propose ProbeCast, a probe based call admission control scheme with QoS guarantees for inelastic flows. ProbCast was designed for multicast streams but can also work, by default, for unicast. In ProbeCast, a path (or a tree) is probed for capacity availability. If an intermediate link along the probed path fails to meet the QoS requirement, the flow is ‘pushed back’ via backpressure upstream to an intermediate branch or possibly to the source. The backpressure principle is simple; however, its implementation requires some care to avoid unfairness and eventual capture by one of the flows sharing a congested bottleneck. We show that proportional fairness among inelastic contenders will prevent capture. To achieve this, we have developed the Neighborhood Proportional Drop (N‐PROD) scheme. N‐PROD guarantees fair rejection of unfeasible flows and maintains the same proportional drop rate among surviving flows in the same contention domain. We demonstrate the efficacy and robustness of ProbeCast for unicast as well as multicast scenarios using the Qualnet simulation platform. Copyright © 2010 John Wiley & Sons, Ltd.

Optimal Priority-based Call Admission Control Scheme For QoS Provisioning in Heterogeneous Wireless Networks

Next generation wireless networks will support a diverse set of access technologies. And the demanding breed of multimedia applications will even more considerably require Quality of Service (QoS) support. This paper proposes an optimal prority-based Call Admission Control (CAC) scheme in heterogeneous wireless networks, i.e., the generalized semi-Markov Decision Process based CAC (GCAC). Considering the limitations of the traditional Markov decision process for optimal CAC policy, we characterize the CAC problem through a GSMDP formulation that characterize s the network behaviors in the heterogeneous system more exactly. And the proposed scheme can guarantee the QoS constrains both in the physical and network layer. Numerical examples illustrate that the performance in the GCAC scheme is significantly better than that in the conventioinal GC scheme and an optimal CAC schme based on MDP.

Cooperation-based resource allocation and call admission for wireless network operators

The increasing number of radio access technologies and the availability of multi-radio devices boost the need for novel resource allocation schemes in cellular networks. This paper uses a cooperative game theoretic approach for resource allocation at the network level, while utilizing simultaneous use of available radio interfaces at the device level. We model resource allocation management using the well known bankruptcy model and apply Kalai-Smorodinsky bargaining solution method to find a distribution rule, based on which we propose resource allocation and call admission control schemes. Performance analysis of our allocation and control schemes demonstrates significant improvements over previous approaches in terms of utilization of the available bandwidth and the number of call drops. We also study the performance of proposed approach for different operator policies.

Admission control by dynamic bandwidth reservation using road layout and bidirectional navigator in wireless multimedia networks

In this paper, we propose a Call Admission Control (CAC) scheme by dynamic bandwidth reservation where a new call is admitted only when both the remaining resource units at the serving Base Station (BS) excluding the resource units of ongoing calls in the BS and the reserved resource units of anticipated incoming handoff calls from direct neighbor cell is enough to accommodate the new call, and when the next cell for this call to visit has enough resource units to accommodate the new call. The proposed call admission control incorporates both mobile information such as position, speed, and next cell to visit by using bidirectional navigator and road layout information. Simulation results show that the handoff call dropping probability and new call blocking probability of our proposed CAC scheme are lower than an existing similar CAC scheme, respectively. To show the practicality of the assumption of having bidirectional navigator for each Mobile Station (MS), we give a simulation where some MSs have bidirectional navigators and some MSs don't have. The simulation results show that more MSs with bidirectional navigators, less the new call blocking probability, while keeping handoff call dropping probability at the same level.

Performance analysis of the CAC scheme CARETON under mixed cell environment in overlay networks

The paper proposes a call admission control (CAC) scheme to offer best services to the users in the next generation heterogeneous networks. It optimises the available resources without compromising the interest of the service providers. It has combined the three commonly used CAC schemes – guard channel, buffer-based and priority-based schemes. It considers wireless overlay model for analysing the heterogeneity with detailed analysis of the WLAN-cellular mixed cell environment. The scheme considers differentiated services for the real time and non-real time calls to provide appropriate quality of service (QoS). The proposed scheme has been evaluated through simulation. The results show that the scheme outperforms some significant CAC schemes and shows even better performance under cellular-WLAN mixed environment due to the dual subscription of the users with dual mobile terminal.

Overlap Area Assisted Call Admission Control Scheme for Communications System

In this paper we propose a novel call admission control scheme named overlap area assisted new call blocking scheme (NCBS-OA) for High Altitude Platform (HAP) based communications systems, which utilizes both the geographical information and the overlap area to intelligently decide when to block a new call to help avoid possible handover failure. An approximate analytical model is derived to estimate the new call blocking performance of the new scheme, which is verified by simulation results. Research results show that the NCBS-OA can improve the new call blocking probability significantly (by a minimum of 25% for the system model with the parameter values chosen) while maintaining a zero handover call dropping probability seen with the time-based channel reservation algorithm (TCRA), and that the greater the cell radius and the more the number of connections considered in the overlap area of a virtual cell, the better the new call blocking performance.

A Novel Call Admission Control Policy Using Mobility Prediction and Throttle Mechanism for Supporting QoS in Wireless Cellular Networks

The decision of call admission becomes an important work owing to the scarce wireless spectrum for wireless cellular networks. If there exists adequate information for call admission control (CAC) schemes, the terms of quality of service (QoS), such as call dropping probability (CDP), call blocking probability (CBP), and system utilization, will be kept in a certain acceptable level. Therefore, a prediction system which can predict most information, such as system utilization and CDP, in advance with a novel data mining technique and a distributed CAC scheme is presented in this paper. Based on the prediction results and the bandwidth consumption of adjacent cells, the proposed CAC scheme is able to decide to admit a new call. The throttle flag that can indicate the usage of current cell is proposed to prevent the newly admitted call request from being blocked in adjacent cells if handoff is needed. The simulation results show that the proposed CAC scheme can maintain the CDP below a predefined threshold, and the CBP is also lower than the cluster prediction and traditional guard channel policies.

SE-CAC: A Novel Call Admission Control Scheme for Multi-service IDMA Systems

In this paper a simple and effective call admission control (CAC) scheme is proposed for the emerging interleave-division multiple-access (IDMA) systems, supporting a variety of traffic types and offering different quality of service (QoS) requirements and priority levels. The proposed scheme is signal-to-interference-plus-noise ratio (SINR) evolution based CAC (SE-CAC). The key idea behind the scheme is to take advantage of the SINR evolution technique in the process of making admission decisions, which is developed from the effective chip-by-chip (CBC) multi-user detection (MUD) process in IDMA systems. By virtue of this semi-analytical technique, the MUD efficiency can be estimated accurately. Additionally, the computational complexity can be considerably reduced. These features make the scheme highly suitable for IDMA systems, which can combat intra-cell interference efficiently with simple CBC MUD. Analysis and simulation results show that compared to the traditional CAC scheme considering MUD efficiency as a constant, the proposed SE-CAC scheme can guarantee high power efficiency and throughput for multimedia traffic even in heavy load conditions, illustrating the high efficiency of CBC MUD. Furthermore, based on the SINR evolution, the SE-CAC can make accurate estimation of available resource considering the effect of MUD, leading to low outage probability as well as low blocking and dropping probability.

Using traffic prediction and estimation of provider revenue for a joint GEO satellite MAC/CAC scheme

Satellite networks present an attractive solution in providing worldwide access to the present and future generation multimedia communication services. However, the burstiness of multimedia traffic and the long propagation delays in Geostationary (GEO) satellite systems call for an efficient Medium Access Control (MAC) protocol and an equally efficient Call Admission Control (CAC) scheme, in order to provide acceptable Quality of Service (QoS) to multimedia users. This paper proposes a fair and dynamic CAC and MAC framework, named Fair Predictive Resource Reservation Access (FPRRA), which is based on accurate videoconference traffic prediction and makes decisions after taking into account the provider revenue. The framework's performance is evaluated in comparison to other efficient schemes from the literature.

A probabilistic approach for fair-efficient call admission control in wireless multiservice networks

The efficiency of call admission control (CAC) schemes in multiclass wireless networks should be evaluated not only with regard to the call blocking probability (CBP) achieved for every service class (SC) supported but also with regard to quality of service (QoS) and network efficiency criteria. In this article, four CAC schemes offering priority to SCs of advanced QoS requirements, based on guard channel policy, are studied and evaluated taking into account fairness and throughput criteria in addition to CBP. For the performance evaluation of the proposed CAC schemes and to examine fairness issues, two fairness indices are introduced along with a throughput metric. The analytical results, validated through extensive simulations, indicate that by appropriate selection of the CAC parameters satisfactory fairness and throughput are achieved while achieving low CBP.