Call Admission Control Policy Research Articles

Correction to: Performance Modeling of Call Admission Control Policy and Handover Management in 5G Ultra-Dense Cellular Network

Correction to: Performance Modeling of Call Admission Control Policy and Handover Management in 5G Ultra-Dense Cellular Network

Performance Modeling of Call Admission Control Policy and Handover Management in 5G Ultra-dense Cellular Network

Performance Modeling of Call Admission Control Policy and Handover Management in 5G Ultra-dense Cellular Network

Handoff Prioritize Call Admission Control Policy for Integrated Macrocell-Femtocell Network

Handoff Prioritize Call Admission Control Policy for Integrated Macrocell-Femtocell Network

A Call Blocking Model and Its Optimal Control Algorithm in LTE Networks

Call admission control must be designed to guarantee both a grade of service (GoS), i.e., probability of blocking new call, probability of forced termination of calls already in progress due to handoffs, and a quality of service (QoS), i.e., signal-to-interference ratio (SIR). Thus how to design appropriately call admission control policy is crucial in the envisioned personal communication networks. Considering user mobility in LTE networks, a call blocking model and its optimal solution algorithm is proposed to identify the criteria with which new mobile terminal requests will be blocked and to define the performance results, which will determine how optimal the resource allocation is.

Handover management with call admission control in integrated femtocell-macrocell network

For achieving high data rate and better indoor coverage and to fulfil high capacity demand, low power-low cost femtocell network is very good option. For successful deployment of femtocell, smooth integration of femtocell network in macrocell network and seamless communication between macrocell and femtocell network is very important. Conventional handoff algorithms used in macrocells need some modifications to satisfy handover management in integrated macrocell femtocell network. In this paper, we have proposed a new hybrid handover approach with call admission control policy which takes care of seamless communication between integrated femtocell-macrocell networks, effective utilisation of femtocells and avoids unnecessary handovers.

An Optimal Joint Call Admission Control Policy in Heterogeneous Wireless Networks

In heterogeneous wireless networks (HWNs), a scheme called Joint Call Admission Control (JCAC) is demanding for deciding whether or not an incoming service request will be accepted. In this paper, we propose an optimal JCAC policy for HWNs based on semi-Markov decision process (SMDP) to achieve the optimal resource management scheme in terms of minimal the network cost and acquire the required quality of service (QoS) of mobile user. Furthermore, an improved value iteration algorithm with multi-dimensional threshold structure is presented. Numerical results show that the proposed JCAC policy is the overall optimal policy. The proposed algorithm is effective for high QoS performance by reducing the probabilities of dropping and blocking calls. The optimal JCAC policy is ratified by the current trend in the design of next generation wireless networks (NGWNs).

Measuring QoS Metrics in Femto/Macro Cellular Networks with CAC Policy

Due to the growing importance of deploying femtocell technology in the current mobile network operators, data traffic processing and handover (HO) management in such networks are challenging issues. Consequently, due to the mobility of femto users between indoor and outdoor environments, the HO traffic interplay between macrocell and femtocells should be addressed, by determining accurate HO rate and actual channel holding time. Classical methods for data traffic process and HO management cannot directly apply in such network. In this paper, we propose an adaptive call admission control (CAC) policy based on a pre-reservation (PR) area as well as we employ the concept of adaptive reserved channel to accomplish quality of service (QoS) requirements for handover traffic requests. A teletraffic model based on queuing theory and Markov chains will allow us to evaluate and quantify QoS metrics performance of the proposed scheme. The numerical results reveal that the benefits of femtocell technology integration with the current macrocellular mobile networks, especially in reducing the traffic loads of macrocell in terms of minimizing blocking probability.

Call Admission Control Scheme and Handover Management in LTE Femtocell-Macrocell Integrated Networks

The femtocell technology is a quick and intelligent solution that improving system coverage and capacity to meet the great demand of services on broadband wireless access, the deployment of access point femtocells will unload a great quantity of traffic from the LTE macrocellular to be managed by the femtocellular network. Switching seamlessly between macrocell and femtocell base stations is a major challenge of LTE femtocell-macrocell integrated system; which is performed by the handover procedure that can guarantee an efficient transfer of UE from/to or between femtocells, and also offer an effective management of handover calls in the system. The intelligent LTE integrated system architecture, a generation and the optimization of neighboring list that contain the best cells for handover, efficient algorithm for call admission control, and also an optimized handover procedure are the most important topics for research. The intelligent LTE integrated system architecture is necessary to satisfy different criteria, as minimizing handover interruption, guarantee and assure minimum signaling overhead due to frequent and unnecessary handovers…so to determine a single handover decision making policy is not sufficient to develop the performance, thus in this paper we propose a call admission control policy to reduce the redundant handovers in the system and an improved process to create a neighboring list with best cells for handover and an appropriate ones for successful and efficient handover. Firstly, we present the LTE femtocell-macrocell integrated network architecture with a large deployment of femtocells. We propose the details signaling flux for handover procedure for different scenarios and the proposed CAC scheme to minimize the unnecessary handovers, based on an optimized neighboring list.

Energy efficiency in heterogeneous wireless access networks

In this article, we bring forward the important aspect of energy savings in wireless access networks. We specifically focus on the energy saving opportunities in the recently evolving heterogeneous networks (HetNets), both Single- RAT and Multi-RAT. Issues such as sleep/wakeup cycles and interference management are discussed for co-channel Single-RAT HetNets. In addition to that, a simulation based study for LTE macro-femto HetNets is presented, indicating the need for dynamic energy efficient resource management schemes. Multi-RAT HetNets also come with challenges such as network integration, combined resource management and network selection. Along with a discussion on these challenges, we also investigate the performance of the conventional WLAN-first network selection mechanism in terms of energy efficiency (EE) and suggest that EE can be improved by the application of intelligent call admission control policies.

Dynamic Threshold-based Congestion Control in Wireless Multimedia Networks

The last few decades have seen a tremendous growth of wireless networks demands due to the need to meet different multimedia applications available over the network. The demand has resulted into greater competition for the scarce available network resources and has introduced congestion in such networks that adversely affect the quality of service requirements of the applications. Call admission control is a key element if provision of quality of service in wireless networks is to be guaranteed. In this paper, a call admission control policy for wireless communication networks based on the use of dynamic threshold-based channel allocation scheme is proposed. The scheme deals with two traffic classes; voice and data with two different but equal channel thresholds, one for each traffic type assumed. The effect of the control parameters on the quality of service parameters is illustrated and analyzed.

A novel approach for the performance bound of QoS-aware data networks under greedy CAC policy

The performance of QoS-aware data networks is measured in terms of acceptance probability of traffic demands requiring an amount of end-to-end bandwidth, which is determined by the Call Admission Control (CAC) policy and the QoS routing algorithm. In this paper, we characterize the theoretical upper bound on the network performance under the greedy CAC policy. Whereas similar problems have been studied in teletraffic networks, the existing approaches consider a specific routing algorithm and obtain its performance. They cannot be used to find performance bound in data networks using complex dynamic QoS routing algorithms. We obtain the bound through modeling the network as a multidimensional Markov chain, which does not depend on a particular routing algorithm. Since this model is computational intensive, the greediest online routing algorithm is developed to estimate the performance bound with lower computational complexity through simulation. In single rate traffic condition, we show that resources allocated by this algorithm for each traffic class is approximately weighted max–min fair. Using this observation, we develop a novel technique to estimate the bound in which an individual loss system is considered per traffic class. Simulation results show that the technique provides an accurate estimation of the bound in a wide range of traffic and network parameter settings.

Dynamic spectrum access based on interruptible spectrum leasing

Dynamic spectrum access (DSA) based on interruptible spectrum leasing allows secondary users (SUs) to lease a licensed, but idle, spectrum that is owned by primary users (PUs) on condition that the PUs preempt the access to the leased spectrum. This paper considers a DSA scenario where the SUs opportunistically use the primary spectrum in addition to their own band and the PUs use their own band regardless of the opportunistic access. This operating scenario can contribute to leverage the spectrum utilization by exploiting underutilized spectrum resources, but involves a problem that the SUs may be forced to interrupt on-going services in response to the PUs' reclamation of the leased spectrum. In this paper, we address the optimal call admission control (CAC) problem in order to coordinate the DSA based on interruptible spectrum leasing by considering the tradeoff between the additional spectrum use and the penalty on the service interruption. To this end, we adopt the profit of the secondary wireless service provider as a cost function of the CAC policy in a market mechanism manner. The optimization problem is modeled as a profit maximization problem, and a linear programming (LP) formulation of the semi-Markov decision process approach is provided. Through the simulation results, we analyze the LP solution of the optimal CAC for the leasing based DSA and demonstrate that the proposed CAC policy judiciously uses the access opportunities of the SUs considering the service interruption.

Challenges of CAC in Heterogeneous Wireless Cognitive Networks

Abstract Call admission control (CAC) is known as an effective functionality in ensuring the QoS of wireless networks. The vision of next generation wireless networks has led to the development of new call admission control (CAC) algorithms specifically designed for heterogeneous wireless Cognitive networks. However, there will be a number of challenges created by dynamic spectrum access and scheduling techniques associated with the cognitive systems. In this paper for the first time, we recommend that the CAC policies should be distinguished between primary users and secondary users. The classification of different methods of cac policies in cognitive networks contexts is proposed. Although there have been some researches within the umbrella of Joint CAC and cross-layer optimization for wireless networks, the advent of the cognitive networks adds some additional problems. We present the conceptual models for joint CAC and cross-layer optimization respectively. Also, the benefit of Cognition can only be realized fully if application requirements and traffic flow contexts are determined or inferred in order to know what modes of operation and spectrum bands to use at each point in time. The process model of Cognition involved per-flow-based CAC is presented. Because there may be a number of parameters on different levels affecting a CAC decision and the conditions for accepting or rejecting a call must be computed quickly and frequently, simplicity and practicability are particularly important for designing a feasible CAC algorithm. In a word, a more thorough understanding of CAC in heterogeneous wireless cognitive networks may help one to design better CAC algorithms.

Insensitive Call Admission Control for Wireless Multiservice Networks

We propose a call admission control policy and prove that the CTMC that models the multiservice wireless system enforcing the CAC scheme is reversible and its stationary distribution is insensitive to the channel holding time distribution.

Dynamic QoS-Based Bandwidth Allocation Framework for Broadband Wireless Networks

Broadband wireless communication systems, namely, Worldwide Interoperability for Microwave Access (WiMAX) and Long-Term Evolution (LTE), promise to revolutionize the mobile users wireless experience by offering many of the services and features promised by fourth-generation (4G) wireless systems, such as supporting multimedia services with high data rates and wide coverage area, as well as all-Internet Protocol (IP) with security and quality-of-service (QoS) support. These systems, however, require proficient radio resource management (RRM) schemes to provide the aforementioned features they promise. In this paper, we propose a new framework, which is called dynamic QoS-based bandwidth allocation (DQBA), to support heterogeneous traffic with different QoS requirements in WiMAX networks. The DQBA framework operates as such; it dynamically changes the bandwidth allocation (BA) for ongoing and new arrival connections based on traffic characteristics and service demand. The DQBA aims at maximizing the system capacity by efficiently utilizing its resources and by being fair, practical, and in compliance with the IEEE 802.16 standard specifications. To achieve its objectives, DQBA employs a flexible architecture that combines the following related components: 1) a two-level packet scheduler scheme; 2) an efficient call admission control policy; and 3) a dynamic BA mechanism. Simulation results and comparisons with existing schemes show the effectiveness and strengths of the DQBA framework in delivering promising QoS and being fair to all classes of services in a WiMAX network.

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.

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.

The effect of call admission policies on the system benefit of CDMA communication networks

Previous studies of call admission control (CAC) in mobile communication networks focused on call blocking and call dropping mechanisms. However, achieving global optimization of the system benefit is a complicated process. In this paper, we propose a benefit optimization model that accommodates as many users as possible, while simultaneously maintaining system-wide quality of service (QoS) in terms of admission control. To clarify the CAC concept, we construct a framework of CAC policies, derive associated interference models based on the framework, and then investigate the effects of the policies on the system benefit. In addition, to solve the complicated integer programming problem, we adopt the Lagrangean relaxation approach, and employ Lagrangean multipliers to perform sensitivity analysis of several parameters. The contribution of this study is twofold: the novel problem formulation and the improvement in the system benefit. The computational results demonstrate that the system accrues more benefit as new traffic is loaded and the number of users increases. Meanwhile, the sensitivity analysis shows that proper assignment of the strength of power-controlled signals is a key factor in the global optimization of the system benefit.

A novel dynamic call admission control policy for wireless network

To address the issue of resource scarcity in wireless communication, a novel dynamic call admission control scheme for wireless mobile network was proposed. The scheme established a reward computing model of call admission of wireless cell based on Markov decision process, dynamically optimized call admission process according to the principle of maximizing the average system rewards. Extensive simulations were conducted to examine the performance of the model by comparing with other policies in terms of new call blocking probability, handoff call dropping probability and resource utilization rate. Experimental results show that the proposed scheme can achieve better adaptability to changes in traffic conditions than existing protocols. Under high call traffic load, handoff call dropping probability and new call blocking probability can be reduced by about 8%, and resource utilization rate can be improved by 2%–6%. The proposed scheme can achieve high source utilization rate of about 85%.

The Uplink Capacity Evaluation of Wireless Networks: Spectral Analysis Approach

In this paper we study the capacity of wireless cellular network, in particular the uplink of WCDMA system by using the two dimensional continuous-time Markov chain (CTMC) technique. Considering two types of calls: real-time (RT) calls that characterized by a quasi fixed transmission rate, and best-effort (BE) calls which do not require strict demand but need some reliability conditions. We develop an approach based on the spectral analysis for evaluating the cell capacity. We explicitly obtain the simultaneous distribution of the number of RT connections and the number of BE connections in the steady-state. This analysis allows us to simplify the computation of the performance measures including expected delay and throughput of BE traffic. These performances are obtained explicitly in both cases (finite and infinite) of BE calls as function of system parameters like arrival rate of BE and RT calls, service rate of BE and RT calls. These results allow the operator to evaluate the cell capacity by varying these parameters independently of the number of BE calls according to its policy to manage the network. Note that this analysis can be applied to various systems such as WiMAX/HSPA, and for both uplink and downlink scenarios, so our spectral analysis approach is not only applicable to the uplink of WCDMA system. We further propose some CAC (Call admission control) policies for BE traffic. We finally conclude this work by some numerical and simulation results. The simulation results obtained by the network simulator (NS2) are closely to the numerical results of our analytical results which validate our theoretical model.