A Dynamic Bandwidth Reservation Scheme based on A Dynamic 2-tier Cell Structure in Cellular Networks

In multimedia wireless networks, when a mobile host (MH) moves to a neighbor cell, it requests the base station (BS) to reserve the bandwidth for seamless handoff. The reservation scheme based on the fixed 2-tier cell structure was proposed to prevent the reservation requests from the MHs close to the BSs. In this reservation scheme, the BS requests the reservation only when the MH is outside of the non-reservation zone which is the area within a fixed distance from the BS. In the fixed 2-tier cell structure, however, low-speed MHs degrade the bandwidth utilization by blocking new calls, because they keep the bandwidth reserved for a long time before handoff. Hence, to improve bandwidth utilization, the size of the non-reservation zone needs to be varied according to the speed of the MH. In this paper, we propose a new bandwidth reservation scheme based on the dynamic 2-tier cell structure. In our structure, the size of the non-reservation zone varies according to the speed of an MH. Our bandwidth reservation scheme determines the target cells for the bandwidth reservation using the current position of each MH and calculates the amount of the reserved bandwidth using the handoff probability. The simulation results show that the proposed scheme has better bandwidth utilization than the conventional reservation scheme based on the fixed 2-tier cell structure.