Service Class Differentiation Research Articles

Research on dynamic RWA algorithm supporting service-differentiated provision

In the multi-service requirement of the next generation of optical networks, differentiated services should be provided, and the transmission quality of signal and the path reliability are two important parameters of service class differentiation. A new dynamic routing and wavelength assignment (RWA) algorithm supporting service-differentiated provision, which takes account of both requirements of the signal transmission quality and the path reliability, is proposed. The numerical results from simulation show that the algorithm can not only overcome the impact of impairment on signal transmission quality and guarantee lightpath reliability, but also offer the service-differentiated lightpath according to its class.

Efficient call admission control scheme for 4G wireless networks

AbstractNext generation wireless networks (NGWNs) will utilize several different radio access technologies, seamlessly integrated to form one access network. This network has the potential to provide many of the requirements that other previous systems did not achieve such as high data transfer rates, effectives user control, seamless mobility, and others which will potentially change the way users utilize mobile devices. NGWN will integrate a multitude of different heterogeneous networks including (a) cellular networks, passed through multiple generations—1G, 2G, 3G, and 3.5G; (b) wireless LANs, championed by the IEEE 802.11 wireless fidelity (WiFi) networks; and (c) broadband wireless access networks (IEEE 802.16, WiMAX). In this paper, a new adaptive quality of service (QoS) oriented CAC scheme is proposed to limit the occurrence of hard IEEE 802.11 WLAN‐UMTS handovers to mobile users using real time (RT) applications. This scheme is hybrid, based on the service class differentiation, the location in the heterogeneous infrastructure and a vertical handoff decision function as well. Simulation results show that our policy achieves significant performance gains. It maximizes the utilization of the resources available at the WLAN cells, and meets as much as possible the QoS requirement of higher priority users. Copyright © 2008 John Wiley & Sons, Ltd.

Combined fair packet scheduling policy and multi‐class adaptive CAC scheme for QoS provisioning in multimedia cellular networks

AbstractIn this paper, we propose a combined multi‐class adaptive connection admission control algorithm and a new fair packet scheduling policy, based on an enhanced weighted fair queuing algorithm. It takes into account a realistic behaviour of traffic while considering the spatial variation of the system characterizing both the user mobility and the signal propagation impairments due to the surrounding effects. The proposed allocation scheme provides enhanced traffic performance in heterogeneous environments and achieves a good level of capacity gain. The new adaptive quality of service (QoS) oriented connection admission control (CAC) function is proposed to meet the rapidly increasing demand for providing multimedia services with diversified quality requirements. It decides whether the connection request is to be admitted into the system, on the basis of the generated interference level and the waiting time before access. This CAC scheme, based on service class differentiation, aims at maximizing the use of available radio resource and meeting the QoS requirement of higher priority users as much as possible while maintaining the minimum requirements of lower priority users, especially when the system suffers from congestion. The results indicate that significantly increased traffic performance can be achieved in comparison with other conventional investigated policies. Copyright © 2006 John Wiley & Sons, Ltd.

Adaptive Assembly on Delay Fairness in Optical Burst Switched Networks

This paper focuses on burst assembly at edge node in optical burst switching networks, which can be implemented to provide the delay QoS guarantee for the whole network. Based on traffic prediction and delay fairness of different classes, a Prediction and delay QoS Burst Assembly (PQBA) mechanism is proposed to reduce the assembly delay and improve the delay fairness especially for high priority service at edge node. We compare the delay, burst size, burst utilization and length error rate of all service classes under different offered load. Simulation studies are carried out for PQBA and the results show that high priority service with relative small burst size achieves a low assembly delay and high burst utilization. Consequently, PQBA realizes the QoS-based delay fairness and service class differentiation at edge node.

A comparison of scheduling mechanisms for service class differentiation in HSDPA networks

Scheduling and service class differentiation in wireless systems is a challenging task. Compared to classical wireline systems, various problems arise from the time-varying and error-prone nature of the radio link. In this paper, we compare classical scheduling mechanisms to provide service class differentiation and their adaptation to the wireless domain, for example, a state-of-the-art HSDPA-system. We highlight the main differences between scheduling in fixed and wireless networks and discuss the advantages and disadvantages of the considered approaches.