Joint Call Admission Control Research Articles

Adaptive joint call admission control scheme for LTE-A in mobile communication network and its performance analysis

Adaptive joint call admission control scheme for LTE-A in mobile communication network and its performance analysis

Resource Allocation for Video Streaming in Heterogeneous Cognitive Vehicular Networks

In future fifth-generation (5G) communication systems, driven by the evolution of today's most demanding applications, video streaming over vehicle networks will play an increasingly significant role in our daily lives. In this paper, based on a heterogeneous architecture consisting of both cellular base stations (BSs) of wide coverage and cognitive-radio-enabled roadside infrastructures, a semi-Markov decision process (SMDP)-based resource-allocation scheme is proposed to facilitate video streaming application in terms of peak signal-to-noise ratio (PSNR) and smooth playback. In addition to improving video quality of vehicle users, quality of service (QoS) provisioning for background users that can originally exist in the cellular network is also considered in the proposed scheme. Specifically, based on the states of the background users, vehicle users, and the availability of the cognitive bands, the optimal resource allocation, aiming at maximizing the video streaming quality while guaranteeing the call-level performance of the background users, is achieved by addressing two interrelated joint call admission control (CAC) and channel allocation problems for cellular and roadside infrastructure networks, respectively. Simulation results show that the proposed scheme can well protect background users when coexisting with bandwidth-hungry vehicle video users and is effective in not only improving video streaming quality for vehicle users but boosting bandwidth utilization of the whole network as well.

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).

Resource Allocation in Hospital Networks Based on Green Cognitive Radios

Pervasive wireless communication and computing can facilitate a variety of e-health applications to communicate patient medical data and information to the doctors/caregivers in an e-Health environment. With the advancement of medical devices and practicing methods the concept of in-cooperating latest communication techniques have taken a new direction by enabling cognitive radio networks in e-Health applications. This paper presents an approach to solve the joint call admission control and power allocation problem in a hospital environment based on green cognitive radio. Specifically, a multi-objective non-convex mixed integer non-linear programming (MINLP) problem of wireless access in an indoor hospital environment is formulated to maximize the number of admitted secondary users and minimize transmit power and carbon dioxide emission. Along with that the throughput requirement of all secondary users and interference constraints for the protected and primary users are also satisfied. In this paper, we invoke outer approximation approach based linearization technique to solve MINLP problem. The proposed method gives guaranteed $$\varepsilon $$? convergence to the optimal solution results with reasonable computational complexity. Simulation results verify the effectiveness of the proposed approach method.

Fairness-based joint call admission control for heterogeneous wireless networks: an SMDP approach

In heterogeneous wireless networks, both terminal heterogeneity and network heterogeneity give rise to the fairness problem of resource allocation. Due to the capability of exploiting the resources of multiple networks, the behavior of multi-mode terminals will have a great effect on single-mode terminals, and this influence becomes more severe when considering the different demands of different traffic. In this article, we propose a novel joint call admission control (JCAC) scheme to address this problem. The JCAC problem is modeled as a semi-Markov decision process (SMDP) with the aim of maximizing the average network revenue under the constraints of the fairness among different terminals and traffic classes. Based on the SMDP, we design an algorithm to achieve a good tradeoff between revenue and fairness by dynamically adjusting the threshold of fairness constraints imposed on heterogeneous terminals. Simulation results show that the proposed scheme can significantly improve the fairness among heterogeneous terminals and guarantee the priority and fairness among different traffic classes with little loss of network revenue compared with other schemes.

Joint call admission control algorithm based on reputation model

In order to make up for the limitation of research scenario of call admission control in heterogeneous wireless networks and reduce blindness of access network selection, the scenario was extended from integrated system with two networks to integrated system with multiple networks, and a joint call admission control algorithm based on reputation model was proposed. The reputation model was applied in the network selection and feedback mechanism. On the user side, the terminals chose the access network according to the networks' reputation; on the network side, the networks made decisions by adaptive bandwidth management and buffer queuing policy to enhance the probability of successful acceptation. Simulation results show that by using the proposed algorithm, new call blocking probability and handoff call dropping probability can be reduced effectively.

A semi-Markov decision process-based joint call admission control for inter-RAT cell re-selection in next generation wireless networks

In the next generation wireless networks (NGWNs), where different radio access technologies (RAT) will coexist and work in collaboration to provide ubiquitous access, a mechanism called Joint Call Admission Control (JCAC) will play an important role by deciding whether or not an incoming service request will be accepted according to an admission constraint as well as determining in which RAT (among the available) it will be connected. In this paper, we propose an optimal JCAC for inter-RAT cell re-selection problem also referred to as initial RAT selection in co-located wireless networks, which supports both real-time services and non-real-time services. To properly meet the JCAC goals, we propose a cost function that weigh two criteria: the blocking cost function, which takes into account the priority of each service class in each RAT, and the alternative acceptance cost, which reflects the multiplicity of RATs working in a collaborative fashion, mandatory in NGWN. We use the framework of Semi-Markov Decision Process (SMDP) to formulate the optimization problem and the value iteration algorithm to compute the optimal policy. Our model still takes into consideration the ratio between the radius of the co-located RATs and shows how it may impact on optimal initial RAT selection. Numerical results, supported by an analysis of the structure of the optimal policy, show that the proposed optimal JCAC selects for real-time service class the biggest RAT and for non-real-time service class the smallest one. This optimal JCAC policy is ratified by the current trend in the design of NGWN and also follows the 3rd Generation Partnership Project (3GPP) expectations.

A Utility-based Optimal Joint Call Admission Control Scheme with Vertical Handoff in Heterogeneous Wireless Networks

This paper comes up with a mechanism of optimal joint call admission control based on different service types. Considering practical wireless transmission environment, it divides the heterogeneous wireless network into several areas and also defines the peak rates that its users could get in each area. The process of call admission control is modeled into a semi-Markov process for the two typical services of streaming media service and elastic traffic which need high band width demand. In accordance with the features of different services, it also defines corresponding admission utility function. The optimal admission strategy with highest admission utility in the whole process of call admission control is obtained on the basis of guaranteeing successful session admission and vertical handoff. Simulation results show that the defined admission utility function could effectively reflect the influence of the change of network status to admission control. The suggested optimal joint call admission control excels the both schemes of non-combined call admission control and non-supporting users' mobility in terms of average admission utility and call blocking rate, and is capable of ensuring lower blocking probability and handoff success ratio.

Adaptive Terminal-Modality-Based Joint Call Admission Control for Heterogeneous Cellular Networks

The coexistence of different Radio Access Technologies (RATs) requires a need for Common Radio Resource Management (CRRM) to support the provision of Quality of Service (QoS) and the efficient utilization of radio resources. The provision of QoS is an important and challenging issue in the design of integrated services packet networks. Call admission control (CAC) is an integral part of the problem. Clearly, without CAC, providing QoS guarantees will be impossible. There is unfairness in allocation of radio resources among heterogeneous mobile terminals in heterogeneous wireless networks. In this paper, an Adaptive-Terminal Modality-Based Joint Call Admission Control (ATJCAC) algorithm is proposed to enhance connection-level QoS and reduce call blocking/dropping probability. The proposed ATJCAC algorithm makes call admission decisions based on mobile terminal modality (capability), network load, adaptive the bandwidth of ongoing call and radio access technology (RAT) terminal support index. Simulation results show that the proposed ATJCAC scheme reduces call blocking/dropping probability.

Multiple-RAT selection for reducing call blocking/dropping probability in cooperative heterogeneous wireless networks

There is an increasing demand for high bandwidth-consuming services such as real-time video and video streaming over wireless access networks. A single radio access technology (RAT) in a heterogeneous wireless network may not always have enough radio resource to admit high bandwidth-consuming calls, such as video calls. Existing joint call admission control (JCAC) algorithms designed for heterogeneous wireless networks block/drop an incoming call when none of the available individual RATs in the network has enough bandwidth to admit the incoming call. Consequently, video calls experience high call blocking/dropping probability in the network. However, some calls such as multi-layer coded (scalable) video can be transmitted/received over one or multiple RATs. This article proposes a JCAC algorithm that selects a single or multiple RATs for scalable video calls in heterogeneous wireless networks, depending on availability of radio resources in available RATs. Non scalable calls are always admitted into a single RAT by the algorithm. The aim of the proposed algorithm is to reduce call blocking/dropping probability for both scalable and non-scalable calls. An analytical model is developed for the proposed JCAC algorithm, and its performance is evaluated. Simulation results show that the proposed algorithm reduces call blocking/dropping probability in heterogeneous wireless networks.

The effect of Radio Resource Management in the performance of Heterogeneous Cellular Networks

Comparing market estimates for wireless personal communication and considering recent wide band multimedia services with the existing spectrum allocations for these types of systems show that spectrum resource management remains a very important topic. The coexistence of different cellular networks in the same geographical area requires joint radio resource management (JRRM) for efficient radio resource utilization and enhancement of quality of service (QoS) provisioning, maintain the planned coverage area and provide high capacity. This paper intends to provide an overview of the RRM problem and envisaged solutions in a Beyond 3G framework. Different scenarios of call admission control inheterogeneous cellular networks are analyzed and compared. Further, we focus on joint call admission control (JCAC) algorithms in heterogeneous cellular networks and present a JCAC model and assumptions for evaluating and discussing the performance of the JCAC algorithm through simulation results.

Immune optimization algorithm for solving joint call admission control problem in next-generation wireless network

The integration of radio access networks with different radio access technologies (RATs) is one of the remarkable characteristics of the next-generation wireless networks (NGWNs). In NGWN, the users with multi-network interface terminals should be able to select independently radio access network to obtain the best service. Therefore, joint call admission control (JCAC) schemes are required to select the most appropriate radio access network (RAN) for incoming calls. We propose an immune algorithm-based JCAC (IA-JCAC) scheme with users centric in order to enhance user's satisfaction. However, JCAC algorithms with users centric can lead to highly unbalanced traffic load among the available RANs in NGWN because users act independently, and most of them may prefer to be connected through a particular RAN. Highly unbalanced traffic load in NGWN will result in high overall call blocking/dropping probability and poor radio result utilization. To solve this problem, we employ dynamic pricing for balancing traffic load among available RANs in heterogeneous wireless networks where users' preferences are considered in decision-making on RAT selection. The proposed IA-based JCAC scheme is compared with another scheme that does not use the dynamic pricing on the performance. The simulation result shows the effectiveness of the proposed IA-JCAC scheme is improved significantly.

Terminal-Modality-Based Joint Call Admission Control Algorithm for Fair Radio Resource Allocation in Heterogeneous Cellular Networks

There is a problem of unfairness in allocation of radio resources among heterogeneous mobile terminals in heterogeneous wireless networks. Low-capability mobile terminals (such as single-mode terminals) suffer high call blocking probability whereas high-capability mobile terminals (such as quad-mode terminals) experience very low call blocking probability, in the same heterogeneous wireless network. This paper proposes a Terminal-Modality-Based Joint Call Admission Control (TJCAC) algorithm to reduce this problem of unfairness. The proposed TJCAC algorithm makes call admission decisions based on mobile terminal modality (capability), network load, and radio access technology (RAT) terminal support index. The objectives of the proposed TJCAC algorithm are to reduce call blocking/dropping probability, and ensure fairness in allocation of radio resources among heterogeneous mobile terminals in heterogeneous networks. An analytical model is developed to evaluate the performance of the proposed TJCAC scheme in terms of call blocking/dropping probability in a heterogeneous wireless network. The performance of the proposed TJCAC algorithm is compared with that of other JCAC algorithms. Results show that the proposed algorithm reduces call blocking/dropping probability in the networks, and ensure fairness in allocation of radio resources among heterogeneous terminals.

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.

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.

Dynamic pricing for load‐balancing in user‐centric joint call admission control of next‐generation wireless networks

AbstractNext‐generation wireless networks (NGWN) will be heterogeneous, comprising of a number of radio access technologies (RATs) co‐existing in the same geographical area. In NGWN, joint call admission control (JCAC) algorithms are required to select the most appropriate RAT for each incoming call. It is envisaged that these JCAC algorithms will be user‐centric (i.e. will consider users' preferences in making RAT selection decisions) in order to enhance user satisfaction. However, user‐centric JCAC algorithms can lead to highly unbalanced traffic load among the available RATs in NGWN because users act independently, and most of them may prefer to be connected through a particular RAT. Highly unbalanced traffic load in NGWN will result in high overall call blocking/dropping probability and poor radio result utilization. To address this problem, we propose dynamic pricing for balancing traffic load among available RATs in heterogeneous wireless networks where users' preferences are considered in making RAT selection decisions. By dynamically adjusting the service price in each of the available RATs, the proposed user‐centric JCAC scheme evens out the unbalanced traffic load caused by independent users' preferences. The JCAC scheme uses fuzzy multiple attribute decision‐making (MADM) technique to select the most appropriate RAT for each incoming call. We develop a Markov model to evaluate the overall call blocking/dropping probability and percentage load in each RAT in heterogeneous wireless networks. Performance of the proposed JCAC scheme is compared with that of a scheme that does not use dynamic pricing. Simulation results are given to show the effectiveness of the proposed JCAC scheme. Copyright © 2009 John Wiley & Sons, Ltd.

Heuristic RAT selection policy to minimize call blocking probability in next generation wireless networks

AbstractIn next generation wireless network (NGWN) where multiple radio access technologies (RAT) co‐exist, a joint call admission control (JCAC) algorithm is needed to make a RAT selection decision for each arriving call. RAT selection policy has a significant effect on the overall new call blocking probability in the network. We propose a heuristic RAT selection policy to minimize new call blocking probability in NGWN. The proposed JCAC scheme measures the arrival rate of each class of calls in the heterogeneous wireless network. Based of the measured values of the arrival rates and using linear programming technique, the JCAC scheme determines the RAT selection policy that minimizes overall call blocking probability in the heterogeneous wireless network. Using Markov decision process, we develop an analytical model for the JCAC scheme, and derive new call blocking probability, handoff call dropping probability (HCDP), and call incompletion probability (CIP). Performance of the proposed scheme is compared with the performance of other JCAC scheme. Simulation results show that the proposed scheme reduces new call blocking probability, HCDP, and CIP in the heterogeneous wireless network. Copyright © 2009 John Wiley & Sons, Ltd.

Adaptive Bandwidth Management and Joint Call Admission Control to Enhance System Utilization and QoS in Heterogeneous Wireless Networks

The coexistence of different cellular networks in the same area necessitates joint radio resource management for enhanced QoS provisioning and efficient radio resource utilization. We propose adaptive bandwidth management and joint call admission control (JCAC) scheme for heterogeneous cellular networks. The objectives of the proposed adaptive JCAC scheme are to enhance average system utilization, guarantee QoS requirements of all accepted calls, and reduce new call blocking probability and handoff call dropping probability in heterogeneous wireless networks. We develop a Markov chain model for the adaptive JCAC scheme and derive new call blocking probability, handoff call dropping probability, and average system utilization. Performance of the proposed adaptive JCAC scheme is compared with that of nonadaptive JCAC scheme in the same heterogeneous wireless network. Results show an improvement in average system utilization of up to 20%. Results also show that connection-level QoS can be significantly improved by using the proposed adaptive JCAC scheme.