Coordinated Call Admission Control for IPv6-based Integrated Hierarchical Wireless Access Networks

Abstract

In recent years, many wireless access systems have been developed to support users mobility and ubiquitous communication. Nevertheless, these systems always work independently and cannot simultaneously serve users properly. In this paper, we aim to integrate IPv6-based wireless access systems and propose a coordinated call admission control mechanism to utilize the total bandwidth of these systems and to minimize the call blocking probabilities, especially the handoff call dropping probabilities. First, we propose an intergrated hierarchical wireless architecture over IPv6-based networks to combine the wireless access systems including PCS, IEEE 802.11 a/b WLAN, and Bluetooth. In the proposed IPv6-based wireless networks, mobile user can request a call with quality of service (Qos) requirements. Once the call is admitted, the mobile user is able to access heterogeneous wireless access networks via multiple interfaces simultaneously. The proposed coordinated call admission control (CCAC) mechanism takes the available bandwidth, the reserved bandwidth, the Qos requirements, and the priority of the incoming call into consideration. The mechanism dynamically adjusts the bandwidth reserved for handoff calls at each level to admit the incoming call or reject it. The CCAC performs well by adjusting the guard channel dynamically and reducing the bandwidth of the admitted low-priority calls. The experimental results show that the CCAC outperforms other mechanisms proposed before