A Flexible QoS-aware Service Gateway for Heterogeneous Wireless Networks

Abstract

ith the rapid development of wireless network technologies, various wireless network infrastructures have been designed and (partially) deployed, such as cellular networks (2G/2.5G/3G), wireless LAN (IEEE 802.11)/wireless MAN (metropolitan area networks) or WiMAX (worldwide interoperability for microwave access -IEEE 802.16) /MobileFi (IEEE 802.20)/WPAN (wireless personal area networks -IEEE 802.15), and a family of digital video broadcasting (DVB) technologies (i.e., DVB-satellite, DVB-cable, DVB-terrestrial, DVB-handheld). Each of these plays an important role in providing ubiquitous computing and a communication infrastructure upon which services operate. To balance the advantages and disadvantages of different wireless networks, two or more networks with different physical structures integrate to form new network structures, called heterogeneous wireless networks (HWNs). For example, cellular networks can benefit not only from the location management of DVB systems [1], they also can be exploited by WLAN or WiMAX, which can divert traffic in a crowded cellular cell and provide a higher data transmission rate in a cost-effective manner [2]. In practice the heterogeneity in network structures is a typical feature of future mobile wireless networks.The future commercial success of these mobile systems lies in their ability to provide users with cost-effective services. In an increasingly mobilized world, users naturally expect that services or applications will follow them, for example, from office or home to airport or to wherever they are. These services are known for high-speed, content-rich, and burst traffic. Therefore, the QoS (Quality of Service) guarantee is critical to these services. The diversity of the network structures, protocols, and standards in HWNs, combined with even more diverse application services from users, pose big challenges for network integration and service integration.Much research has been performed on the convergence of two types of wireless networks, especially the convergence of cellular networks with WLAN based ad hoc networks [2] and the convergence of cellular networks and DVB networks [1]. The focus is primarily on certain technical aspects of the convergence such as location management, routing, and so on. In this article, we propose a HWN architecture that is composed of three types of wireless access networks: cellular networks, ad hoc networks, and broadcasting networks, and in particular, UMTS (universal mobile telecommunications system), ad hoc WLAN, and DVB-H, respectively -as such, the so-called UWD network. Three networks cooperate and complement each other to support different services and to optimize network resource utilization. Instead of focusing on a specific technical challenge of UWD, we focus on the network architecture and its service-driven adaptation and management. To this end, we utilize a policy-based management (PBM) approach in combination with fuzzy control theory, aiming to maximize the overall effectiveness, flexibility, and robustness of the ne...

Multiple Downlink Fair Packet Scheduling Scheme in Wi-Max

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