An adaptive bandwidth reservation scheme for 4G cellular networks using flexible 2-tier cell structure

Many mechanisms based on bandwidth reservation have been proposed in the literature to decrease connection dropping probability for handoffs in cellular communications. The handoff events occur at a much higher rate in packet-switched fourth generation mobile communication networks than in traditional cellular systems. An efficient bandwidth reservation mechanism for the neighboring cells is therefore critical in the process of handoff during the connection of multimedia calls to avoid the unwillingly forced termination and waste of limited bandwidth in fourth generation mobile communication networks, particularly when the handoff traffic is heavy. In this paper, an adaptive two-tier scheme, which employs grey prediction theory and swarm intelligence techniques, is proposed to reduce the forced termination probability of multimedia handoffs. The simulation results show that the proposed scheme can achieve superior performance than the representative bandwidth-reserving schemes in the literature when performance metrics are measured in terms of the forced termination probability for the handoffs, the call blocking probability for the new connections and bandwidth utilization. 2010 Elsevier Ltd. All rights reserved.