An admission control scheme for QoS-sensitive cellular networks

We propose an admission control scheme to guarantee a certain level of QoS to on-going connections in cellular networks. This admission control scheme is based on a differential bandwidth reservation policy that uses a sector of cells in making bandwidth reservation for accepting the new call. The sector of cells, which are located along the way to which the MT might move, are further divided into two regions depending on whether they have an immediate impact on the handoff or not. Two different bandwidth reservation policies are applied to cells in the two regions to optimize the connection dropping rate (CDR) while maximizing the connection blocking rate (CBR). In contrast to most prior policies, the proposed admission control scheme uses varying number of cells in the sector to make admission decision. Depending on the currently measured average CDR of the cells in the sector and the current cell where a new connection is generated, the number of cells involved in admission control can be changed dynamically to satisfy the target QoS (CDR) parameter. Simulation results indicate that our admission control policy guarantees the required CDR over the entire workload, while maintaining a competitive CBR. Comparison of the proposed scheme with two prior schemes shows that our approach is not only capable of providing better QoS guarantees, but also is more flexible in terms of using varying number of cells in satisfying a certain QoS requirement.