A Novel Backoff Algorithm with QoS Support in Heterogeneous Wireless Networks

Abstract

Abstract-The main objective of the future networks is to provide users with always best connectivity through available different access networks. Wireless convergence has emerged as a multidimensional concept that combines networks, applications, user interfaces and management, which aimed at supporting voice, data and multimedia over IP-based networks. In this paper, we model the end-to-end quality of service (QoS) provisioning mechanisms in the wireless local area network (WLAN) and worldwide interoperability for microwave access networks (WiMAX) interworking network. For the end to end QoS guaranteed service, we make changes to multiple access protocol. The media access control (MAC) analysis using hybrid protocol based on virtual slot multiple access (VSMA) with a novel backoff mechanism is extended to the heterogeneous networks and its throughput and delay characteristics are analyzed. By the simulation results, our proposed protocol can provide the low end to end delay and improved throughput for different traffics, even though the traffic load in the network increases. Especially, the end-to-end delay of the IP based voice is smaller when the QoS parameter mappings are applied to the interworking network.Index Terms-Backoff mechanism, medium access control, WiMAX, WLAN. I. INTRODUCTIONThe advent of ubiquitous computing and the growth of portable computing devices have raised the importance of mobile and wireless networking. With the rapid growth of the Internet and interactive facilities of multimedia-based services, the current wireless technology is flourishing in every aspect of human life ranging from home, education, medicine, e-commerce and m-commerce. Today, almost every network technology is prepared or even explicitly designed to transport IP-packets. To meet the ever increasing consumer demands the mobile networks have evolved from first generation (1G) to fourth generation (4G) [1].In order to ensure consistent user experience across heterogeneous wireless networks, the main challenge is to provide end-to-end QoS and to optimize transmission of all data, voice, and video applications to and among end users. The performance needs of applications are characterized by four key parameters: bandwidth, packet loss, delay, and jitter (i.e., delay variation), which determine the QoS.Overall, the needs of the distinct applications are different with respect to QoS. For example, some popular data applications (such as e-mail and Web access) require low to Manuscript received February 15, 2012; revised April 25, 2012. The authors are with the Department of Electronics Engineering, School of Engineering and Technology, Pondicherry Central University, Puducherry, INDIA (e-mail: rajeshatnet@gmail.com; rnakeeran @ pec.edu). medium bandwidth and are quite relaxed as far as the delay and jitter are concerned. On the other hand, Video-on-Demand (VoD) flows have relaxed requirements on delay, but they do need high bandwidth and cannot tolerate much packet loss or jitter. Voice over IP (VoIP), while tolerating som...