Call Admission Control Algorithm Research Articles

A novel statistical and distributed CAC algorithm for IEEE 802.11 based single and multi-hop wireless ad hoc networks

In this paper, we propose a statistical Call Admission Control (CAC) schemes for single and multi-hop IEEE 802.11 based wireless ad hoc networks. Unlike most papers which consider average end-to-end delay, our algorithm guarantees statistical delay that would be more efficient for real time multimedia applications. We use Effective Bandwidth/Effective Capacity theory to compute delay bound stochastically in each hop. The proposed distributed CAC algorithm is suitable for ad hoc networks. Also, with a few changes, it has been implemented in the AODV routing protocol. Simulation results demonstrate that proposed CAC algorithm works efficiently in both single and multi-hop networks. Moreover, we investigated our algorithm with aggregated traffic and the result shows that the algorithm performed accurately under that condition.

Novel, graded, priority-oriented admission control in mobile networks

Call admission control plays a crucial role in providing quality of service to the different services in mobile broadband networks (WiMAX, LTE). A new connection is admitted only when the network can support the QoS needs of the connection without degrading the QoS for existing connections. An efficient call admission control algorithm ensures higher throughput and fewer delays for the admitted connections. In this paper a graded priority-based call admission control algorithm is proposed for LTE and WiMAX networks. The number of permissible connections shall be segregated into two classes. The new connection shall be graded, prioritized, and admitted based on the device requesting the connection. Simulation results show that graded priority-based admission control algorithm improves the connection admission rate from 3% to as high as 30% for select users. This results in higher throughput for priority users.

A Self-Similar Call Admission Control Algorithm in WiMAX

Modelling WiMAX network traffic based on the self-similarity character is better than the traditional model based on the Poisson process, because the former can provide more accurate calculation for effective bandwidth. In this paper we propose a WiMAX network traffic model based on M/Pareto model to describe its self-similarity character. Then we deduce the average transmission rate and the variance coefficient for the FBM traffic model by the M/Pareto model, and get the Hurst parameter of the FBM traffic model by statistical analysis method. By the FBM traffic model we get a formula for calculating the effective bandwidth. Accordingly, we propose a modified self-similar call admission control algorithm (SS-CAC). SS-CAC can avoid measuring the parameter values of FBM traffic flow to do call admission control. Simulation results show that SS-CAC greatly reduces the call blocking rate and improves the bandwidth utilization.

Handover management framework for WiMAX Point-to-Multi-Point networks

In this paper, a distributed base station cooperation-based handover management method is proposed for WiMAX Point-to-Multi-Point networks to provide quality of service to handover nodes. Moreover, a delay reduction method is proposed to reduce the packet delivery delays during handover. A Call Admission Control (CAC) algorithm is proposed to handle handover calls of various service classes fairly, according to their priorities. A bandwidth borrowing scheme is proposed to reduce the handover call dropping probabilities of various service classes while not starving the ongoing calls of lower priority service classes. A Markov model is developed to analyze the proposed CAC method and to obtain the approximate handover call dropping probabilities of various service classes. Simulation experiments are conducted to establish the performance advantages of the proposed handover management and CAC methods.

An effective cross-layer designed packet scheduling, call admission control, and handover system for video streaming services over LTE network

This paper presents an effective cross-layer designed packet scheduling, call admission control, and handover system to provide a seamless video streaming services over LTE network. The proposed packet scheduling algorithm allocates wireless network resources to admitted UEs while considering QoE states and wireless link states of UEs simultaneously. The proposed call admission control algorithm estimates the cell availability at the next call arriving time based on the current QoE states of UEs to determine the admission of a new UE. The proposed handover algorithm determines the appropriate handover trigger timing to keep a balance of the QoE states among immediately adjacent cells based on both the cell availability and wireless link states. Finally, simulations are conducted to evaluate the performance of the proposed system. Results indicate that the proposed cross-layer designed system improves the QoE states of all admitted UEs and overall network utilization better than other existing methods.

Performance Analysis of WiMAX Networks: Discrete Event Simulator (DES) Development

Simulation is one of the most widely performance analysis technique used in academia for the evaluation of resource management algorithms in (WiMAX networks. Different simulation tools are available, including public, private and standalone simulators. However, these simulators have a complex structure and require enormous licensing cost, which limit their use. In this paper, we propose a general programming language based discrete event simulation for WiMAX networks. The research focus is on developing a (DES) built from the scratch that provides ease of use and customization. It implements packet scheduling algorithms and Call Admission Control (CAC) algorithm for WiMAX. The results show that the developed simulator achieves similar results with the benchmarks. These findings have shown that our simulator has become a reliable performance analysis alternative for WiMAX resource management evaluations.

Performance Analysis of Handoff Calls for Quality of Service using Call Admission Control Algorithm for Data, Video and Voice Traffic

Call admission control is a very important measure in CDMA system to guarantee the quality of the communicating links. In future wireless networks multimedia traffic will have different QoS requirements. The call admission control is very important measure in CDMA system to guarantee the quality of the communicating link In future wireless networks multimedia traffic will have different QoS requirements. We have proposed call admission and call control algorithms for QoS provisioning for multimedia traffic in a cellular mobile network. In this paper we propose a call admission control algorithm that keeps the dropping probability below a specified level while achieving high channel utilization.

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.

MetroNet: a disruption‐tolerant approach for mobile downloads on metro systems

ABSTRACTIn this study, we propose a disruption‐tolerant network based system called MetroNet, which exploits the precise schedules of metro systems to pre‐fetch data and facilitate mobile Internet downloads, even if an end‐to‐end path between the source (i.e. content sources) and the destination (i.e. users) does not exist contemporaneously. Using a comprehensive set of simulations, as well as real‐world scenarios of the Taipei and Atlanta metro systems, we demonstrate that MetroNet can handle the intermittent Internet connectivity caused by mobility and therefore provide a better mobile download service. The simulation results demonstrate that the proposed call admission control algorithm utilises the network resource effectively and provides better quality of service for mobile users than the first‐come‐first‐serve and least‐first algorithms. Copyright © 2013 John Wiley & Sons, Ltd.

Energy-aware QoS uplink scheduling for UGS traffic flows in WiMAX networks

This paper presents a new energy-aware QoS scheduling and call admission control algorithm for WiMAX IEEE 802.16e wireless access standard. The scheduling algorithm works at MAC layer and is designed towards minimizing power consumption at mobile stations supporting multiple Unsolicited Grant Service (UGS) connections, while meeting the QoS requirements of the connections. The algorithm uses a novel idea to fill an active OFDM frame as much as possible in order to increase the number of OFDM frames in sleep mode at mobile station. The algorithm also considers the dynamic nature of connection joining and termination. We used Voice-over-IP (VoIP) traffic connection models for UGS traffic flows to simulate and validate algorithm. The simulation model was tested using VoIP codec types with different rates and QoS requirements. Simulation results show that a power saving in the range of 50–75% can be easily achieved at the mobile station under low-to-moderate traffic intensities.

Quality of service analysis and resource allocation scheme for Long‐Term Evolution network

SUMMARYIn this paper, we analyze the quality of service (QoS) framework supported by the Long‐Term Evolution standard and model the behavior of a finite‐state downlink wireless fading channel based on the configurations and system parameters provided by the 3GPP Long‐Term Evolution and provide experimental results. The model can be used to provide realistic physical layer input to evaluate the performance of algorithms at the upper layers. For example, the medium access control layer will use this data to test the performance of scheduling, admission control, power control, and so on. The QoS requirements at the physical layer, the data link layer, and the cross‐layer modeling are stated. Then, we present a QoS‐based call admission control algorithm that considers admission of calls for future start‐up as well as the immediate and hand‐off calls with a certain priority admission scheme. Analytical study based on two‐dimensional Markov chain is also provided. We then use a stochastic discrete event simulator to evaluate the performance of the call admission control algorithm. The results obtained for look‐ahead admission are compelling and indicate the usefulness of making advance resource reservations. Copyright © 2013 John Wiley & Sons, Ltd.

New adaptive frame aggregation call admission control (AFA‐CAC) for high throughput WLANs

AbstractThe major enhancements introduced by the very high throughput wireless local area network, cannot provide quality of service (QoS) satisfaction for real time and multimedia applications. The recent standard IEEE 802.11n introduced new Medium Access Control (MAC) mechanisms based on aggregation scheme to enhance throughput. Besides that, functional modules for QoS provisioning such as call admission control and bandwidth management should be implemented in the access point. Hence, an efficient call admission control (CAC) algorithm is required for 802.11n network to satisfy QoS requirements of strict multimedia services. In this paper, we propose a new model‐based call admission control algorithm, called adaptation of frame aggregation AFA‐CAC to be implemented within the QoS access point in IEEE 802.11n standard in a way to provide QoS satisfaction to real time services. We first propose an accurate analytical model to estimate the achieved QoS metrics of a new flow entering in the network. Then, we detailed the AFA‐CAC algorithm that supports IEEE 802.11n aggregation schemes aggregated MAC service data unit and aggregated MAC protocol data unit and consider the IEEE 802.11e enhanced distributed channel access. AFA‐CAC is based on both predicting the QoS constraints of the already active flows and the new flow, and adjusting the number of aggregated subframes of each flow. Conducted simulations illustrate the performance of our proposed AFA‐CAC in terms of satisfying QoS throughput and end‐to‐end delay requirements of voice and video traffics. Copyright © 2013 John Wiley & Sons, Ltd.

Opportunistic call admission control for wireless broadband cognitive networks

Wireless Broadband Cognitive Networks (WBCN) are new trend to better utilization of spectrum and resources. However, in multiservice WBCN networks, call admission control (CAC) is a challenging point to effectively control different traffic loads and prevent the network from being overloaded and thus provide promised quality of service. In this paper, we propose a CAC framework and formulate it as an optimization problem, where the demands of both WBCN service providers and cognitive subscribers are taken into account. To solve the optimization problem, we developed an opportunistic multivariate CAC algorithm based on a joint optimization of utility, weighted fairness, and greedy revenue algorithms. Extensive simulation results show that, the proposed call admission control framework can meet the expectations of both service providers and subscribers in wireless broadband cognitive networks.

A Multi-Class on Time Call Admission Control for Wireless Broadband Cognitive Networks

Wireless Broadband Cognitive Networks (WBCN) are new trend in networking for better utilization of spectrum and resources. However, in multiservice WBCN networks, Call Admission Control (CAC) is a challenging point to effectively control different traffic loads and prevent the network from being overloaded and thus provide promised QoS. In this Study, we propose a CAC framework and formulate it as an optimization problem, where the demands of both WBCN service providers and cognitive subscribers are taken into account. To solve the optimization problem, we developed an opportunistic multivariate CAC algorithm based on a joint optimization of utility, weighted fairness and greedy revenue algorithms. Extensive simulation results show that, the proposed call admission control framework can meet the expectations of both service providers and subscribers in wireless broadband cognitive networks.

Adaptive control of call acceptance in WCDMA network

Adaptive control of call acceptance in WCDMA network

PHY/MAC Enhancements and QoS Mechanisms for Very High Throughput WLANs: A Survey

Wireless local area networking has experienced tremendous growth in the last years with the proliferation of IEEE 802.11 devices in order to improve wireless technology. The first generation of high throughput networks known as IEEE 802.11n was developed in 2009 to reach 130 Mbps. Furthermore, to enhance the throughput, two new amendments for IEEE 802.11 are under developments which are IEEE 802.11ad and IEEE 802.11ac. The first one aims to reach 1Gbps with supporting multi-user access techniques. The second amendment aims to enable up to 7Gbp with the possibility of transmitting in the 60GHz band that provides the opportunity for much wider band channels. Another WLAN is already finalized called IEEE 802.11aa in the goal to provide a reliable multicast transport for video streaming. In this survey, we examine the different PHY and MAC enhancements introduced by all these WLAN specifications. Particularly, we focus on the characteristics of each amendment as well as the main MAC mechanisms that lead to improve the network performance. Based on the fact that all recent MAC mechanisms aim to increase QoS guarantee for real time multimedia applications, we have studied different schemes and mechanisms that provide QoS satisfaction for real time multimedia flows transport over WLANs. Namely, we investigate the scheduling mechanisms, the call admission control algorithms, and the anticipated MAC enhancement which are proposed for WLANs networks to support real time applications with QoS satisfaction.

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.

UTILITY BASED SCHEDULING AND CALL ADMISSION CONTROL FOR LONG TERM EVOLUTION NETWORKS

In this study, we propose to design a call admission control algorithm which schedules the channels for Real time and non-real time users. In Long Term Evolution (LTE) 3GPP Networks, several works were done on call admission control but these works rarely considers scheduling of resources to the real time and non-real time users.When the system meets traffic oriented performance degration, maximum resources are utilized for load balancing and to maintain the consistent quality. In order to avoid the channel degradation and improve the Quality of Service (QoS), the call requests are classified into New Call (NC) request and Handoff Call (HC) request and the type of services are classified as VoIP and video. Then based upon the Received Signal Strength (RSS) value, the channel is estimated as good channel or bad channel. Resource allocation is made for VoIP users based on traffic density. Then non-VoIP users and the non-real time users are allocated resource blocks using the channel condition based marginal utility function. When there are no sufficient resources to allocate, it allocates the resources of bad channel users there by degrading their service. We have designed the network topology with G (n) and B (n) for representing the available good and bad channels. We investigate the performance degradation when the real time, Non real Time, video and VOIP environments based on RSS threshold value.Comparison is made with the VOS in terms of the paramenters like throughput,bandwidth,delay,fairness and rate. Our proposed method provides good performance and quality.From our simulation results we show that this admission control algorithm provides channel quality and prioritizes the handover calls over new calls which allocates resources to all kinds of users.

A Novel Routing Mechanism with Distributed Call Admission Control Algorithms in MANET

A Novel Routing Mechanism with Distributed Call Admission Control Algorithms in MANET

LTE 网络中具备QoS 保障的动态负载均衡算法

In this paper, dynamic load balancing with different quality-of-service (QoS) requirements is investigated in 3GPP long-term evolution (LTE) networks. Load unbalancing among neighboring cells often has different negative impacts on users with different QoS demands. For users with minimum rate requirements, the load unbalancing results in high new call blocking rate, while for users with no rate guarantees, the throughput of boundary users in an overloaded cell often significantly decreases. Furthermore, the different load unbalancing problems are coupled with each other so that it is difficult to analyze the problem in a uniform manner. To deal with this issue, a multi-objective optimization problem is proposed. The objectives in the problem are load balancing index of users with QoS requirements and the total utility function of users without QoS requirements, and the constraints are physical resource limits and QoS demands. Then the complexity of the problem is analyzed, and a real-time distributed algorithm framework with low complexity/overhead is proposed, which includes a QoS guaranteed hybrid scheduling scheme, handover of users with and without QoS requirements, and a call admission control algorithm. Extensive simulations are conducted and the results show that the proposed algorithm framework leads to significantly better load balancing so as to yield the decrement of new call blocking rate of users with QoS requirements, and the increment of throughput of boundary users with only a bit degradation of total throughput of users without QoS requirements.