Seamless QoS-Aware Call Admission Control Policy in Heterogeneous Wireless Networks

The design criterion of call admission control policy in heterogeneous wireless networks (HWN) is to make full use of the spectrum resources in different radio access systems, under the constraint of seamless QoS. In order to overcome the shortcoming of the traditional optimal guard channel policy (OGCP) in providing seamless QoS, a definition of balance channel is proposed firstly, and then a QoS fairness factor is defined to measure the difference in QoS level between different areas of the HWN. Accordingly, a seamless QoS-aware call admission control policy in HWN is proposed, which is called the balance and guard channel policy (BGCP). In BGCP, the admission control problem is formulated as an optimization problem under the constraint of QoS fairness factor, and the optimizing object is to minimize the grade of service (GoS) of the HWN. Simulation results show that, in comparison with OGCP, the proposed admission control policy successfully provides the seamless QoS guarantee for the multi-mode mobile terminals, at the cost of a very little decrease in resource utilization.