Development of call admission control schemes for guaranteeing QoS in wireless heterogeneous networks

Abstract

Next-generation wireless networks will combine heterogeneous networks to create novel ways to provide various services simultaneously such as information access, voice and (or) video transactions, entertainment and monitoring. Since each network has its own advantage and disadvantage, the resulting integrated network can become more efficient network as accepting advantages and complementing disadvantages of integrated networks. However, since each network has been developed individually, it is a strong challenge today that heterogenous networks work together harmoniously. In this dissertation, we deal with a 3G-WLAN integrated network where 3G-cellular network and WLAN cooperate to guarantee QoS requirement for one service. In the 3GWLAN integrated network, two networks share the database for the customers to provide seamless services and the mobile terminal (MT)s of the customers need to support the access capabilities for both networks. Here, we have to consider a new kind of handoff, called the vertical handoff (VHO), in addition to the horizontal handoff (HHO) which is generally considered in homogeneous networks, i.e., the VHO is a new factor to be added up in the integrated network. Hence, there are more complex channel requests and channel returns in the 3G-WLAN integrated network. However, 3G cellular network and WLAN have tried separately to utilize the radio resource more efficiently subject to QoS requirement. Then, it is needed to study the radio resource management for such a new factor, the VHO, to be considered in the integrated network. From this view point, we study some call admission control (CAC) schemes to utilize the overall radio resource efficiently in the 3G-WLAN integrated network. We use guard channel to give priority simply to some types of channel requests which are more important to customers. We propose two different GC based CAC scheme in this dissertation. In the first GC based CAC scheme, we concentrate the effects from mobili...